The certification of trace elements mass fraction in electrolytic copper ERM®-EB074A, B and C : certification report.
Date: 2015-06-16
Institutions: Institute for Reference Materials and Measurements
Subjects: Community certification, copper, industrial production, industrial research, materials technology, research report, resistance of materials, sampling, spectrometry, technical standard

CERTIFICATION REPORT 

The certification of trace elements mass fraction in 
electrolytic copper: 
ERM®-EB074A, B and C 

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JRC-IRMM promotes a common and reliable European measurement  
provides reference measurements. 

European Commission 
Joint Research Centre 
Institute for Reference Materials and Measurements (IRMM)  

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JRC92119 

EUR 26890 EN 

ISBN 978-92-79-43606-2 (PDF) 
ISSN 1831-9424 (online) 
doi:10.2787/10090 

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© European Union, 2015 

Reproduction is authorised provided the source is acknowledged. 
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Abstract 
This report describes the production of ERM®-EB074A, B and C, a pure copper material with low level of added impurities certified for the mass 
fractions of Ag, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, P, Pb Sb, Se, Te, Ti and Zn. The material was produced following ISO Guide 34:2009 . 
A melt is consisting of pure copper and alloy to obtain a copper material with added impurities. After casting, the material was processed by hot 
extrusion and cold machining to produce discs of 39 mm diameter (ERM-EB074A), cylinders of 8 mm diameter (ERM-EB074B) and chips of 250 mg 
(ERM-EB074C). 
Between unit-homogeneity was quantified and stability during dispatch and storage were assessed following ISO Guide 35:2006. Within-unit 
homogeneity was quantified to determine the minimum sample intake. 
The material was characterised by an intercomparison among laboratories of demonstrated competence and adhering to ISO/IEC 17025. Technically, 
invalid results were removed but no outlier was eliminated on statistical grounds only.  
Uncertainties of the certified values were calculated in compliance with the Guide to the Expression of Uncertainty in Measurement (GUM); the 
estimated total uncertainty includes uncertainties related to possible inhomogeneity, instability and characterisation. 
The material is intended for use in the quality control and assessment of method performance. As any reference material, it can also be used for 
control charts or validation studies. The certified reference material (CRM) is available in three different formats: 
- ERM-EB074A: disc of 39 mm diameter; 30 mm thick; packed in a a box 
- ERM-EB074B: cylinder of 8 mm diameter; 100 mm length; sealed in a plastic sachets under vacuum 
- ERM-EB074C: bottle of 50 g of chips; chip weight of approximately 250 mg 

For ERM-EB074A, B and C, the minimum amount of sample to be used is 10 mg for Ag, As, Be, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Ti and Zn; 20 
mg for Au, In and Te. 

The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials Consortium.

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
CERTIFICATION REPORT 

The certification of trace elements mass fraction in 
electrolytic copper:  
ERM®-EB074A, B and C 

Thomas BACQUART, Thomas P.J. LINSINGER 

European Commission, Joint Research Centre 
Institute for Reference Materials and Measurements (IRMM) 
Geel, Belgium 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Disclaimer 

Certain commercial equipment, instruments, and materials are identified in this paper to specify adequately the 
experimental  procedure.  In  no  case  does  such  identification  imply  recommendation  or  endorsement  by  the 
European Commission, nor does it imply that the material or equipment is necessarily the best available for the 
purpose.  

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Summary 

This report describes the production of ERM®-EB074A, B and C, a pure copper material with 
low level of added impurities certified for the mass fractions of Ag, As, Au, Be, Bi, Cd, Co, Cr, 
Fe, In, Mg, Mn, Ni, P, Pb Sb, Se, Te, Ti and Zn. The material was produced following ISO 
Guide 34:2009 [1]. 

A  melt  is  consisting  of  pure  copper  and  alloy  to  obtain  a  copper  material  with  added 
impurities. After casting, the material was processed by hot extrusion and cold machining to 
produce  discs  of  39  mm  diameter  (ERM-EB074A),  cylinders  of  8  mm  diameter  (ERM-
EB074B) and chips of 250 mg (ERM-EB074C). 

Between  unit-homogeneity  was  quantified  and  stability  during  dispatch  and  storage  were 
assessed  following  ISO  Guide  35:2006  [2].  Within-unit  homogeneity  was  quantified  to 
determine the minimum sample intake. 

The material was characterised by an intercomparison among laboratories of demonstrated 
competence  and  adhering  to  ISO/IEC  17025  [3].  Technically,  invalid  results  were  removed 
but no outlier was eliminated on statistical grounds only.  

Uncertainties  of  the  certified  values  were  calculated  in  compliance  with  the  Guide  to  the 
Expression  of  Uncertainty  in  Measurement  (GUM)  [4];  the  estimated  total  uncertainty 
includes uncertainties related to possible inhomogeneity, instability and characterisation. 

The  material  is  intended  for  use  in  the  quality  control  and  assessment  of  method 
performance. As any reference material, it can also be used for control charts or validation 
studies. The certified reference material (CRM) is available in three different formats: 

- ERM-EB074A: disc of 39 mm diameter; 30 mm thick; packed in a a box 

- ERM-EB074B: cylinder of 8 mm diameter; 100 mm length; sealed in a plastic 

sachets under vacuum 

- ERM-EB074C: bottle of 50 g of chips; chip weight of approximately 250 mg 

For ERM-EB074A, B and C, the minimum amount of sample to be used is 10 mg for Ag, As, 
Be, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Ti and Zn; 20 mg for Au, In and Te. 

The  CRM  was  accepted  as  European  Reference  Material  (ERM®)  after peer  evaluation  by 
the partners of the European Reference Materials consortium. 

1 

 
 
  
 
 
 
 
 
 
 
 
 
 
The following certified values were assigned for ERM-EB074A, B and C: 

Mass Fraction 

Certified value 1) 
[mg/kg] 
1.03 

Uncertainty 2) 
[mg/kg] 
0.07 

1.23 

0.52 

0.31 

0.51 

0.40 

0.83 

0.37 

5.8 

0.49 

2.03 

0.93 

0.61 

1.53 

2.7 

0.57 

0.55 

0.50 

0.97 

2.2 

0.08 

0.06 

0.06 

0.04 

0.04 

0.06 

0.04 

0.8 

0.07 

0.27 

0.07 

0.08 

0.25 

0.4 

0.04 

0.07 

0.06 

0.18 

0.4 

Ag 

As 

Au 

Be 

Bi 

Cd 

Co 

Cr 

Fe 

In 

Mg 

Mn 

Ni 

P 

Pb 

Sb 

Se 

Te 

Ti 

Zn 

1) Unweighted mean value of the means of accepted sets of data each set being obtained in a 
different  laboratory  and/or  with  a  different  method  of  determination.  The  certified  value  and  its 
uncertainty are traceable to the International System of Units (SI). 

2) The uncertainty of the certified value is the expanded uncertainty with a coverage factor k = 2 
corresponding  to  a  level  of  confidence  of  about  95  %  estimated  in  accordance  with  ISO/IEC 
Guide 98-3, Guide to the Expression of Uncertainty in Measurement (GUM:1995), ISO, 2008. 

2 

 
 
 
 
 
Table of Contents 

Summary .............................................................................................................................. 1 
Table of Contents ................................................................................................................ 3 
Glossary ............................................................................................................................... 4 
Introduction .............................................................................................................. 7 
1 
Background ............................................................................................................... 7 
1.1 
Choice of the material ................................................................................................ 7 
1.2 
Design of the project .................................................................................................. 8 
1.3 
Participants .............................................................................................................. 8 
2 
Project management and evaluation .......................................................................... 8 
2.1 
Processing ................................................................................................................. 8 
2.2 
Homogeneity study .................................................................................................... 8 
2.3 
Characterisation ......................................................................................................... 8 
2.4 
Material processing and process control .............................................................. 9 
3 
Origin/Purity of the starting material ........................................................................... 9 
3.1 
Processing ................................................................................................................. 9 
3.2 
Process control .........................................................................................................12 
3.3 
Homogeneity ...........................................................................................................12 
4 
Between-unit homogeneity........................................................................................13 
4.1 
4.2  Within-unit homogeneity and minimum sample intake...............................................22 
Homogeneity uncertainty of ERM-EB074A, B and C .................................................25 
4.3 
Stability....................................................................................................................26 
5 
Characterisation .....................................................................................................27 
6 
Selection of participants ............................................................................................27 
6.1 
6.2 
Study setup ...............................................................................................................27 
6.3  Methods used ...........................................................................................................28 
Evaluation of results .................................................................................................28 
6.4 
Value Assignment ...................................................................................................33 
7 
Certified values and their uncertainties .....................................................................33 
7.1 
Indicative values and their uncertainties....................................................................34 
7.2 
Additional material information ..................................................................................35 
7.3 
8 
Metrological traceability and commutability .........................................................36 
8.1  Metrological traceability ............................................................................................36 
Commutability ...........................................................................................................36 
8.2 
Instructions for use ................................................................................................37 
9 
Safety information .....................................................................................................37 
9.1 
Storage conditions ....................................................................................................37 
9.2 
9.3 
Preparation and use of the material ..........................................................................37 
9.4  Minimum sample intake ............................................................................................37 
Use of the certified value ..........................................................................................37 
9.5 
Acknowledgments ..................................................................................................38 
10 
References ..............................................................................................................39 
11 

3 

 
Glossary 
AC 
ASTM 
International 
ANOVA  
b 
BCR® 

BIPM 

CEN 
CI 

CRM 

DC 
EC 
EN 
ERM® 
ETV 
EU 
GD 
GUM 
ICP 
ICP-MS 
IGF 
INAA 
IR 
IRMM 
ISO 
JRC 
k 
k0-NAA  
LA 
LOD 
MS 
MSbetween 
SDS 
MSwithin  
n 
N 
n.a. 
n.c. 
n.d. 
NIST 
OES 
QC 
rel 
RM 
RSD 
s 
sbb

sbetween 

Alternating current 
ASTM International (formerly American Society for Testing and 
Materials) 
Analysis of variance 
Slope in the equation of linear regression y = a + bx 
One of the trademarks of CRMs owned by the European Commission; 
formerly Community Bureau of Reference 
Bureau International des Poids et Mesures (International Bureau of 
Weights and Measures) 
European Committee for Standardization 
Confidence interval 

Certified reference material 

Direct current 
European Commission 
European norm (standard) 
Trademark of European Reference Materials 
Electro-thermal vaporisation 
European Union 
Glow discharge 
Guide to the Expression of Uncertainty in Measurements [4] 
Inductively coupled plasma 
Inductively coupled plasma-mass spectrometry 
Inert gas fusion 
Instrumental neutron activation analysis 
Infra-red 
Institute for Reference Materials and Measurements of the JRC  
International Organization for Standardization  
Joint Research Centre of the European Commission 
Coverage factor 
k0-Neutron activation analysis 
Laser ablation 
Limit of Detection 
Mass spectrometry 
Mean of squares between-unit from an ANOVA 
Safety data sheet 
Mean of squares within-unit from an ANOVA 
Number of replicates per unit 
Number of samples (units) analysed 
Not applicable 
Not calculated 
Not detectable 
National Institute of Standards and Technology (USA) 
Optical emission spectrometry 
Quality control 
Index denoting relative figures (uncertainties etc.) 
Reference material 
Relative standard deviation 
Standard deviation 
Between-unit standard deviation; an additional index "rel" is added when 
appropriate 
Standard deviation between groups as obtained from ANOVA; an 
additional index "rel" is added as appropriate 

4 

 
 
 
SI 
smeas 

sns 
swithin 

swb 
ta

, df 

u 
U 
u*

bb  

ubb 

uchar  

uCRM 

UCRM  

u∆ 

umeas 
Umeas 
urec  

usts 

ut 
VIM 
VIDP 
x  
nsx  
refx
a  
D meas 

n s,meas 
n

MSwithin

 and df 

International System of Units 
Standard deviation of measurement data; an additional index "rel" is 
added as appropriate 
Standard deviation of results of normal stock samples 
Standard deviation within groups as obtained from ANOVA; an additional 
index "rel" is added as appropriate 
Within-unit standard deviation 
Critical t-value for a t-test, with a level of confidence of 1-a
degrees of freedom 
Standard uncertainty  
Expanded uncertainty 
Standard uncertainty related to a maximum between-unit inhomogeneity 
that could be hidden by method repeatability; an additional index "rel" is 
added as appropriate 
Standard uncertainty related to a possible between-unit inhomogeneity; 
an additional index "rel" is added as appropriate 
Standard uncertainty of the material characterisation; an additional index 
"rel" is added as appropriate 
Combined standard uncertainty of the certified value; an additional index 
"rel" is added as appropriate 
Expanded uncertainty of the certified value; an additional index "rel" is 
added as appropriate 
Combined standard uncertainty of measurement result and certified 
value 
Standard measurement uncertainty 
Expanded measurement uncertainty 
Standard uncertainty related to possible between-unit inhomogeneity 
modelled as rectangular distribution; an additional index "rel" is added as 
appropriate 
Standard uncertainty of the short-term stability; an additional index "rel" 
is added as appropriate 
Standard uncertainty of trueness 
Vacuum induction melting 
Vacuum induction degassing pouring 
Arithmetic mean 
Arithmetic mean of all results of normal stock samples  
Arithmetic mean of results of reference samples 

Significance level 
Absolute difference between mean measured value and the certified 
value 
Degrees of freedom for the determination of the standard deviation smeas 
Degrees of freedom of MSwithin 

5 

 
 
 
 
 
 
 
 
6 

 
 
 
1  Introduction  

1.1  Background 

Copper  is  essential  for  humans  in  their  daily  life  and  industry.  Copper  was  one  of  the  first 
metals  ever  extracted  and  used  by  humans  (e.g.  coins,  ornaments)  and  one  of  the  first 
alloying  metal  with  zinc  (brass),  aluminium  and  tin  (bronze)  [5].  Copper  is  important  to  the 
development of human civilisation (e.g. Bronze Age). 

Currently,  copper  is  present  in  various  sectors  and  industries:  building  construction,  power 
generation  and  transmission,  electronic  product  manufacturing,  production  of  industrial 
machinery and the transportation sector [6]. Its relevance is due to its physical (ductility) and 
chemical properties (excellent thermal and electrical conductivity, corrosion resistance) [7] its 
high antimicrobial activity [8]. 

Copper  is  traded  internationally;  production  and  transformation  of  copper  (from  cathode  to 
semi-finished product and final production) are widespread geographically. The demand for 
refined copper was estimated to be 0.5 million tons in 1900 and was 20 million tons in 2012 
[5].  The  copper  market  is  an  important  globalised  market,  which  drives  the  need  for 
international standardisation. 

Depending  on  the  commodity  exchange,  the  chemical  composition  of  electrolytic  copper 
cathode is defined according to three standards: EN 1978:1998 (Cu-CATH-1) [9], GB/T 467-
2010  (Cu-CATH-1)  [10]  and  ASTM  B115-10  (cathode  Grade  1)  [11].  These  require  the 
determination of 12 to 18 elements which should, alone or in groups of a few elements, not 
exceed upper limits of a few mg/kg: Ag, As, Bi, Cd, Co, Cr, Fe, Mn, Ni, P, Pb, S, Sb, Se, Si, 
Sn, Te and Zn [9-11].  

The  price  of  copper  is  established  as  a  function  of  the  impurity  levels,  the  premium  being 
paid for very low levels and penalties for high levels.  

As  the  analyses  of  impurities  at  these  very  low  levels  are  subject  to  many  possibilities  of 
error, the  industry  has  a  strong  need for  reliable  certified reference materials  to  ensure  the 
quality and the accuracy of their measurements. 

To support the industry,  two CRMs for trace elements in copper were produced in 1992 
within the scope of the European Commission's BCR-programme. The two CRMs (BCR-074 
and BCR-075 [12]) are close to exhaustion and need replacement. 

In addition to the elements required by the various standards, eleven elements (Al, Au, Be, 
H, Hg, In, Mg, O, Ti, W and Zr) were found to be of interest for copper industry and quality 
control  laboratories  involved  in  copper  trade.  These  elements  were  considered  relevant  for 
the certification or as indicative values and were included in the scope of the project. 

1.2  Choice of the material 

ERM-EB074  is  produced  from  pure  copper  with  the  addition  of  low-level  impurities.  The 
addition  of  impurities  permits  achieving  pre-defined  levels  of  trace  elements  more  easily. 
These  levels  of  trace  elements  were  chosen  to  below  the  limits  set  in  the  international 
standards. The levels of trace elements are similar to those of the nearly exhausted CRM for 
trace elements in electrolytic copper: BCR-074 [12]. 

The  material  was  produced  in  three  different  formats  in  compliance  with  the  various 
analytical methods used by industry:  

ERM-EB074A:  discs  of  39  mm  diameter  were  designed  for  solid  sampling  techniques  (e.g. 
spark optical emission spectrometry (spark-OES) or glow discharge mass spectrometry (GD-
MS)),  

7 

 
ERM-EB074B: cylinders of 8 mm diameter were designed for solid sampling techniques (e.g. 
GD-MS) and analysis after acid dissolution, 

ERM-EB074C: chips of approximately 250 mg were designed for solid sampling techniques 
(e.g. direct current arc optical emission spectrometry (DC-arc-OES)) and analysis after acid 
dissolution. 

1.3  Design of the project 

After processing, homogeneity of the materials was evaluated in a dedicated study of each 
material  format  using  different  techniques.  The  homogeneity  results  of  the  three  formats 
were  finally  pooled  to  obtain  an  overall  uncertainty.  The  stability  was  assessed  using  a 
similar  existing  material.  The  certification  was  performed  using  an 
interlaboratory 
comparison.  The  results  showed  no  difference  between  the  three  formats,  so  one  single 
value for each element for all three formats could be assigned. 

2  Participants 

2.1  Project management and evaluation 

European  Commission,  Joint  Research  Centre,  Institute  for  Reference  Materials  and 
Measurements (IRMM), Geel, BE 
(accredited to ISO Guide 34 for production of certified reference materials, BELAC No. 268-RM) 

2.2  Processing  

European  Commission,  Joint  Research  Centre,  Institute  for  Reference  Materials  and 
Measurements (IRMM), Geel, BE 

Luvata Pori Oy, Pori, FI 

Wieland-Werke, Ulm, DE 

2.3  Homogeneity study 

Alfred H Knight International Ltd, St Helens, UK 

Evans Analytical Group SAS, Tournefeuille, FR 

Umicore Analytical competence center, Olen, BE 

Umicore Analytical Competence Center, Hanau-Wolfgang, DE 

2.4  Characterisation 

Activation Laboratories Ltd., Ancaster, CA 
(measurements performed under the scope of ISO/IEC 17025 accreditation, SCC No. 266) 

Aurubis AG, Hamburg, DE 

Bundesanstalt für Materialforschung und –prüfung (BAM), Berlin, DE 
(measurements performed under the scope of ISO/IEC 17025 accreditation, DAkkS No. DP-L-11075-14-00) 

CCR affinerie, Montreal, CA 

Evans Analytical Group LLC, Liverpool, NY, US 

Evans Analytical Group SAS, Tournefeuille, FR 

Institut "Jozef Stefan" (IJS), Department of Environmental Sciences, Ljubljana, SI 
(measurements performed under the scope of ISO/IEC 17025 accreditation, Slovenska Akreditacija-LP090) 

Laboratory Testing Inc., Hatfield, US 
(measurements performed under the scope of ISO/IEC 17025 accreditation, A2LA No. 0117.05) 

8 

 
 
 
National Research Council Canada, Ottawa, CA 
(measurements performed under the scope of ISO/IEC 17025 accreditation, SCC No. 474) 

Umicore Analytical Competence Center, Olen, BE 

Umicore Analytical Competence Center, Hanau-Wolfgang, DE 

Studiecentrum voor Kernenergie, SCK, Mol, BE 
(measurements performed under the scope of ISO/IEC 17025 accreditation; BELAC No. 015-TEST) 

TU Delft, Delft, NL 
(measurements performed under the scope of ISO/IEC 17025 accreditation; Rva L049) 

Ultra Traces Analyses Aquitaine (UT2A), Pau, FR 

3  Material processing and process control 

3.1  Origin/Purity of the starting material 

The starting materials were pure copper (purity > 99.999 %) from Luvata Pory Oy (Pori, FI), 
pure metals (Ag, Al, Au, In, Ni, Pb, Sb, Sn and Zn; purity > 99.7 %) and copper master alloys 
(CuAs30,  CuBe4,  CuBi2,  CuCd50,  CuCo15,  CuCr10,  CuFe20,  CuMg20,  CuMn50,  CuP10, 
CuS20,  CuSe37,  CuSi10,  CuTe50,  CuTi30,  CuZr50;  purity  >  99.5  %)  from Wieland Werke 
(Ulm,  DE).  The  specifications  of  the  starting  material  complied  with  international  standards 
EN 1981: 2003 [13]) and were documented in certificates of analysis from producers.  

3.2  Processing 

The production of ERM-EB074A, B and C was done in two steps: 

- Melting and casting of copper rods with added impurities, 

- Extrusion of copper billets and mechanical processing into final dimensions. 

Melting  and  casting  of  copper  with  added  impurities  and  the  first  extrusion  into  rods  was 
realised  by Wieland-Werke (Ulm,  DE). The  rods were  then  processed  into  their final  shape 
by Luvata Pori Oy (Pori, FI). The production scheme is detailed in Figure 1.  

9 

 
 
Starting 
materials 

Pure copper  
Purity > 99.999 % 

Pure metals and master alloys  
Purity > 99.5 % 

Production 
of copper 
with added 
impurities 

Vacuum induction 
melting process 

(VIDP furnace) 

Casting in 2 moulds 

Billet 
1 

Billet 
2 

Hot extrusion to 
diameter 9.8 mm 

Cold drawing to 
diameter 8 mm 

Hot extrusion to 
diameter 40 mm 

Processing to 
final unit 
dimensions 

Preparation of chips: cold 
drawing to diameter 3 mm and 
cutting of chips (250 mg) 

Preparation of 
cylinder: Cutting 
and engraving 

Preparation of discs: 
Cutting, surface 
polishing and engraving 

Cleaning and 
packaging 

ERM-EB074C 
Bottle 50 grams 
 Chip: 250 mg  

Cleaning and 
packaging 

Cleaning and 
packaging 

ERM-EB074B 
Cylinder Ø 8 mm 
Length 100 mm 

ERM-EB074A 
Disc Ø 39 mm 
Thickness: 30 mm 

Final units 

Figure 1: Processing scheme of ERM-EB074A, B and C 

3.2.1  Melting and casting of copper billets with added impurities 

The first step of the production was obtaining a homogeneous melt of pure copper with the 
added  impurities  by  Wieland-Werke  (Ulm,  DE)  by  vacuum  induction  melting  (VIM),  a 
technique  for  melting  metal  via  electromagnetic  induction  under  vacuum.  An  induction 
furnace  containing  an  electrographite  crucible  surrounded  by  an  induction  coil  is  located 
inside a vacuum chamber. The induction furnace is connected to an AC power source at a 
frequency that is precisely correlating to the furnace size and the material being melted. 

10 

 
 
 
 
 
The advantages of VIM are: 

-  Homogeneous  distribution  of  chemical  elements  in  the  material  due  to  constant 

stirring of the molten metal during melting and casting; 

- Limitation of non-metallic oxide inclusions. Melting under vacuum helps to limit metal 

reactivity with atmospheric oxygen; 

-  Precise  adjustment  of  alloy  composition,  since  the  temperature,  vacuum,  gas 
atmosphere,  pressure  and  material  transport  (e.g.  through  stirring  of the  bath)  can 
be adjusted independently of one another. 

The VIM technique produces a highly homogenous melt and allows casting of materials with 
controlled  composition.  The  crucible  used  for  melting  was  a  dedicated  electrographite 
crucible, which mitigates the risk of metallic contamination. 

Approximately  2.2  tons  of  copper  were  charged  into  the  electrographite  crucible  in  the 
vacuum  induction  degassing  pouring  furnace  (VIDP  furnace)  under  vacuum  (10-1  –  10-2 
mbar). The molten metal composition was then adjusted using the different pure metals and 
master  alloys  until  the  precise  melt  chemistry  was  achieved.  The  manufactuer performed  a 
single analysis to verify the composition before casting. After verification, two copper billets 
were cast in two different moulds. 

3.2.2  Extrusion of copper billets and mechanical processing into final dimensions 
The two copper billets were dispatched for the production of ERM-EB074A, B and C by hot 
extrusion and mechanical machining. 

ERM-EB074A: Production of discs 

One  and  a  half  billets  were  dedicated  to  the  production  of  ERM-EB074A  (discs  with  a 
diameter  of  39  mm).  Each  billet  was  first  cut  into  two  parts,  and  hot  extruded  to  a  final 
diameter  of  40  mm  by  Wieland-Werke  (Ulm,  DE).  The  three  last  rods  had  a  length  of  nine 
meters; they were labelled and cut into three parts for further processing. 

From  the  nine  last  rods  (diameter:  40  mm;  length:  3  m),  7  rods  were  selected  for  final 
processing by Luvata Pori Oy (Pori, FI). The rods were cut to 30 mm length and polished (on 
all  surfaces),  the  final  diameter  after  polishing  is  39  mm.  The  discs  were  engraved 
mechanically  on  the  curved  surface  with  “74-XXX”.  The  code  “74-XXX”  corresponds  to  the 
material  ID  (74  stands  for  ERM-EB074)  and  the  unit  number  (XXX).  Then,  the  discs  were 
degreased,  cleaned  with  deionised  water,  dropped  into  2-propanol  /  isopropanol  and  dried. 
Finally, the discs were visually checked at IRMM and packed in individual cardboard boxes. 

ERM-EB074B and C: production of cylinders and chips 

A half billet was dedicated to the production of ERM-EB074B and C. The half billet was hot 
extruded to diameter of 9.8 mm and then processed to 8 mm diameter using cold drawing by 
Wieland-Werke  (Ulm,  DE).  In  total,  61  rods  were  obtained  with  a  diameter  of  8  mm  and  a 
length of 3 m. 

Thirty-five rods were selected after analysis of Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, 
Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, W, Zn and Zr by GD-MS (one GD-MS analysis 
per  rod)  and  rods  with  grossly  deviating  values  were  excluded  from  further  processing 
(Section 3.3). Nine rods were randomly selected for the production of ERM-EB074B and 26 
rods for the production of ERM-EB074C. 

For  ERM-EB074B,  the  nine  selected  rods  were  cut  into  cylinders  of  100  mm  length  and 
engraved mechanically with the code “74-XXX” by Luvata Pori Oy (Pori, FI). Afterwards, the 
cylinders  were  degreased,  cleaned  with  deionised  water,  dropped  into  2-propanol  / 

11 

 
isopropanol and dried. The final batch of cylinders was visually checked at IRMM and packed 
into plastic sachets sealed under vacuum. 

For  ERM-EB074C,  the  26  selected  rods  were  processed  to  3  mm  diameter  using  cold 
drawing  by  Luvata  Pori  Oy  (Pori,  FI). The  material  obtained  was  cut  into  pieces  of  250 mg 
(with a relative tolerance of 3 %). The pieces were grouped per rods (~ 5200 pieces per rod) 
and followed a cleaning process (degreasing, cleaning with deionised water, rinsing with 2-
propanol  /  isopropanol  and  drying).  Finally,  50  g  of  chips  were  placed  into  cleaned  amber 
glass bottles, flushed with inert gas (Ar) and closed. 

The final products were:  

ERM-EB074A: 550 units. Each unit is a disc of 39 mm diameter with thickness of 30 mm; 

ERM-EB074B: 240 units. Each unit is a cylinder of 8 mm diameter with length of 100 mm; 

ERM-EB074C:  675  units.  Each  unit  is  a  bottle  containing  50  g  of  chips.  Each  chip  has  a 
mass of approximately 250 mg.  

3.3  Process control  

Several controls of the composition and the homogeneity of trace elements in copper in the 
semi-finished  products  were  realised  by  the  manufacturer  during  the  melting  (one 
composition analysis by GD-MS) and after casting of the two billets (one GD-MS analysis on 
the  top  and  bottom  of  each  billet).  No  major  element  inhomogeneity  was  observed  by  the 
measurements. 

Before processing the 8 mm rods into their final formats ERM-EB074B  and C, one GD-MS 
analysis was performed on every 8 mm rod for Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, 
Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, W, Zn and Zr by GD-MS (data not shown). The 
objective  was  to  select  the  thirty-five  8  mm  rods  for  the  production  of  ERM-EB074B  and  C 
and  to  exclude  outlying  values  and  extreme  values  (highest  and  lowest  values  for  each 
element). 

Visual control was done for each unit during the packaging. A few units were excluded due to 
major scratches or unclear engraving. 

The  segregation  between  billets  is  a  source  of  inhomogeneity  in  metal  production;  the 
different  processing  steps  could  be  another  source  of  difference  between  the  formats  A,  B 
and C. It was studied during the process control (data not shown) and it is detailed in Section 
4.1.2. 

4  Homogeneity 

A key requirement for any reference material is the equivalence between the various units. In 
this respect, it is relevant whether the variation between units is significant compared to the 
uncertainty of the certified value. It is not relevant if the variation between-units is significant 
compared to the analytical variation. Consequently, ISO Guide 34 requires RM producers to 
quantify  the  between-unit  variation.  This  aspect  is  covered  in  between-unit  homogeneity 
studies. 

Production  of  metallic  CRMs 
inhomogeneity sources have to be taken into account:  

requires  extensive  homogeneity 

test  since  several 

-  Trend  or  segregation  within  billet:  during  the  casting  some  elements  are  known  to 
segregate  within  the  billet,  e.g.,  lead  in  copper.  The  trend  or  segregation  within  billet  was 
tested using ERM-EB074A units from one billet (Section 4.1.2). The outcome of the study is 
considered  to  be  similar  for  all  billets  as  they  were  melted  and  cast  under  the  same 
conditions. 

12 

 
 
-  Between-billet  homogeneity  (Section  4.1.3):  the  final  material  is  composed  of  two  casted 
billets that may show differences due to the melting or casting process (i.e. inhomogeneity of 
the  melt,  delay  in  casting)  for  some  elements  (see  Section  3.3.2).  Between-billet 
homogeneity was studied using a large number of ERM-EB074A units from the two billets. 

- Between-unit homogeneity (Section 4.1.4). 

- Within-unit  inhomogeneity  is  essential  for  solid  sampling  techniques  (e.g., GD-MD,  spark-
OES).  These  techniques  use  tiny  sample  intake  and  are  subject  to  differences  due  to  the 
aliquot  location  (radial  homogeneity  on  discs;  Section  4.2.1)  and  to  the  sample  intake 
(minimum sample intake). 

The within-unit inhomogeneity does not influence the uncertainty of the certified value when 
the minimum sample intake is respected, but determines the minimum size of an aliquot that 
is representative for the whole unit. Quantification of within-unit inhomogeneity is, therefore, 
necessary to determine the minimum sample intake. 

4.1  Between-unit homogeneity 

The between-unit homogeneity was evaluated to ensure that the certified values are valid for 
all units of the material, within the stated uncertainty. 

4.1.1  Study setup 
The between-unit homogeneity study was performed for each format independently using an 
appropriate  analytical  method  (Table  2).  This  approach  allows  coherence  among  the 
intended use, homogeneity estimation and the minimum sample intake.  

The  within-billet  homogeneity  and  the  between-billet  homogeneity  were  evaluated  using 
results  on  the  ERM-EB074A  units  (Table  2).  The  evaluation  of  these  three  studies  was 
necessary to select the most appropriate uncertainty estimation (sbb, u*

bb or urec). 

35 units of ERM-EB074A, 27 units of ERM-EB074B and the 29 bottles of ERM-EB074C were 
selected  using  a  random  stratified  sampling  scheme  covering  the  whole  batch  for  the 
between-unit homogeneity test. For this, the batch was divided into 27, 29 or 35 groups (with 
a similar number of units) and one unit was selected randomly from each group.The number 
of  selected  units  (35  units  for  ERM-EB074A,  27  units  for  ERM-EB074B  and  29  bottles  for 
ERM-EB074C) corresponds to more than 3.8 % of the production of each format (more than 
the  cubic  root  of  the  total  number  of  the  produced  units)  and  is  considered  sufficient  to 
represent a lot/batch consisting of large number of units for which it is impractical to test 8 % 
of the units as recommended in ASTM E826 [14].  

Four independent aliquots for Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, P, 
Pb, S, Sb, Se, Si, Sn, Te, Ti, W, Zn, Zr and three independent aliquots for O were taken from 
each  selected  unit,  and  analysed  by  glow  discharge  mass  spectroscopy  and  by  inert  gas 
fusion  with  IR  detection  for  ERM-EB074A  and  B.  For  ERM-EB074C,  four  independent 
aliquots for As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, P, Pb, Sb, Se, Sn, Te, Ti and 
W  and  three  independent  aliquots  for  O  and  S  were  taken  from  each  selected  unit,  and 
analysed  by  ICP-MS,  ICP-OES  (for  Ag,  Al,  Si,  Zn  and  Zr),  by  inert  gas  fusion  with  IR 
detection  (O)  and  by  combustion  with  IR  detection  (S).  A  summary  of  the  study  is  given  in 
Table 2. 

13 

 
 
 
Table 2: Summary of the homogeneity study. 

Material 
format 

Within-billet 
homogeneity study 
Number of units 
selected 

Between-unit 
homogeneity study 
Number of units 
selected 

ERM-
EB074A 

1 billets 
15 discs 

35 discs 
(15-20 discs per 
production billet) 

ERM-
EB074B 

ERM-
EB074C 

n.a. 

27 cylinders 

n.a. 

29 bottles 

Elements 

Techniques 

Number of 
replicates / 
Number of 
analytical runs 

Ag, Al, As, Au, Be, Bi, 
Cd, Co, Cr, Fe, Hg, 
In, Mg, Mn, Ni, P, Pb, 
S, Sb, Se, Si, Sn, Te, 
Ti, W, Zn, Zr 
O 
As, Au, Be, Bi, Cd, 
Co, Cr, Fe, Hg, In, 
Mg, Mn, Ni, P, Pb, S, 
Sb, Se, Sn, Te, Ti, W  
O 
Ag, As, Au, Be, Bi, 
Cd, Co, Cr, Fe, Hg, 
In, Mg, Mn, Ni, P, Pb, 
Sb, Se, Sn, Te, Ti, W, 
Zn, Zr 
Ag, Al, Si, Zn, Zr 
O 
S 

GD-MS 

4 / 4 

IGF-IR 

GD-MS 

IGF-IR 

3 / 3 

4 / 4 

3 / 3 

ICP-MS 

4 / 4 

ICP-OES 
IGF-IR 
Combustion-IR 

4 / 4 
3 / 3 
3 / 3 

The  measurements  were  performed  in  a  randomised  block  design  because  the  number  of 
replicates  on  all  units  (81  -  140  analyses)  could  not  be  included  in  a  single  run  due  to 
instrumental  constraints  (drift  towards  the  end  of  a  long  run,  time  of  analysis).  Improved 
precision (measured as the within-unit standard deviation) was obtained using several short 
runs in a randomised block design compared to the one achieved in a single run with 81 to 
140 analyses. 

The  design  applied  consisted  of  three  to  four  measurement  sequences,  each  comprising  a 
single measurement on each unit. The order of units in each run was randomised individually 
for  each  sequence  to  separate  a  potential  analytical  drift  from  a  trend  in  the  processing 
sequence.  

A  two-way  analysis  of  variance  without  replication  was  used  to  estimate  the  within-  and 
between-unit standard deviations independently any potential analytical sequence effect. 

For two elements (Hg and W), the results in all units were reported below the detection limit 
of the method (0.01 mg/kg). The data treatment was not applied to these two elements. 

For Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn, 
Zr, the data evaluation was performed in the following order: 

1 – Trends in analytical run / correction for significant trends  

Regression  analyses  were  performed  to  evaluate  potential  trends  in  each  analytical  run. 
Some  significant  (95  %  confidence  level)  trends  in  the  analytical  sequence  were  visible; 
indicating a signal drift in the analytical system (Tables 3-5). The correction of biases, even if 
they  are  statistically  not  significant,  allows  the  combination  of  the  smallest  uncertainty  with 
the  highest  probability  to  cover  the  true  value  [11].  Correction  of  trends  was  therefore 
expected to improve the sensitivity of the subsequent statistical analysis through a reduction 
in  analytical  variation  without  masking  potential  between-unit  heterogeneities.  As  the 
analytical  sequence  and  the  unit  numbers  were  not  correlated,  trends  significant  at  95  % 
confidence level were corrected as described in equation 1.  

14 

 
 
 
 
 
),(x T
ir

=

),(x
ir

rb

)(

i

Equation 1 

i 

r 

b(r) 

x(r,i)  

xT(r,i)  

position of the result in the analytical run 

number of the analytical run from 1 to 4 

slope of the linear regression for the analytical run r 

measurement results on the position i in the analytical run r 

corrected results for analytical trend in the position i in the analytical run r 

2 – Evaluation of between-analytical run effect / Normalisation of dataset (if necessary) 

The  analytical  trend-corrected  dataset  was  evaluated  for  significant  differences  between 
analytical  runs  (95  %  confidence  level)  using  one-way  ANOVA.  Significant  differences 
between  analytical  runs  were  observed  on  the  95  %  confidence  level  for  all  elements  in 
ERM-EB074A (except O) in ERM-EB074B (except for Cr, Fe, Si and Zr) and for Al, As, Au, 
Bi, Co, Fe, Mn, Ni, Sb, Se, Si, Zn, Zr in ERM-EB074C (Tables 3-5). As it is assumed that run 
effects  and  unit  effects  are  independent,  the  differences  between  analytical  runs  on  95  % 
confidence level were normalised as described in equation 2.  

x

R

),(
ir

=

),(x
ir
T
)(
rx
T

x
T

Equation 2 

i 

r 

Tx  

)(rxT

xT(r,i)  

xR(r,i)  

position of the result in the analytical run 

number of the analytical run from 1 to 4 

mean results of all the analytical runs 

mean  results  of  the  analytical  run  r  after  correction  for  the  trend  in  analytical 
sequence (if necessary) 

corrected results for analytical trend on the position i in the analytical run r 

normalised results on the position i in the analytical run r 

3 – Statistical evaluation of the datasets 

The  normalised  datasets  were  tested  for  consistency  using  Grubbs  outlier  tests  on  a 
confidence level of 99 % on the individual results, and the unit means (Tables 3-5). The unit 
means for ERM-EB074A, B and C are presented graphically in Annex A.  

15 

 
 
(cid:215)
-
 
 
·
 
 
 
 
Table 3: Results of the statistical evaluation of the homogeneity studies of ERM-EB074A; n = 
number of outliers; T = number of series with an analytical trend. 

ERM-
EB074A 

Analyte 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

Analytical trends 

Significant at 95% 
confidence level 
(T) 
Yes (1) 
No 
Yes (2) 
Yes (3) 
Yes (1) 
Yes (3) 
No 
Yes (2) 
Yes (4) 
Yes (3) 
Yes (2) 
Yes (3) 
Yes (1) 
Yes (1) 
No 
Yes (4) 
Yes (3) 
Yes (1) 
Yes (3) 
Yes (2) 
Yes (1) 
No 
Yes (2) 
Yes (3) 
Yes (2) 
Yes (4) 

Between analytical run 
difference 
Tested with one way 
ANOVA 
Significant difference at 
95% confidence level 
(F-test) 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
No 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 

Outliers at 99% 
confidence level 

Distribution 

Unit 
means 
(n) 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 

Individual 
results 
(n) 
No 
Yes (1) 
No 
No 
No 
Yes (1) 
Yes (1) 
No 
No 
No 
Yes (1) 
No 
No 
No 
Yes (2) 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
Yes (2) 
No 
Yes (1) 

Unit 
means 

Individual 
results 

bimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
bimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
bimodal 
bimodal 
unimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
unimodal 

bimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
bimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
bimodal 
bimodal 
unimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
bimodal 
unimodal 
unimodal 
bimodal 
unimodal 

Table 4: Results of the statistical evaluation of the homogeneity studies of ERM-EB074B; n = 
number of outliers; T = number of series with an analytical trend. 

ERM-
EB074B 

Analyte 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

Analytical trends 

Significant at 95% 
confidence level 
(T) 
Yes (1) 
No 
Yes (1) 
Yes (1) 
Yes (1) 
Yes (1) 
No 
Yes (4) 
Yes (4) 
Yes (2) 
Yes (1) 
Yes (1) 
Yes (3) 
Yes (3) 
Yes (1) 
Yes (1) 
Yes (1) 
No 
Yes (3) 
Yes (1) 
No 
No 
Yes (2) 
Yes (3) 
Yes (1) 
Yes (3) 

Between analytical run 
difference 
Tested with one way ANOVA 
Significant difference at 95% 
confidence level 
(F-test) 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
No 
No 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
Yes 
No 
Yes 
Yes 
Yes 
Yes 
No 

16 

Outliers at 99% 
confidence level 

Distribution 

Unit 
means 
(n) 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 
No 
No 
Yes (1) 
No 
No 
No 
No 
No 

Individual 
results 
(n) 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
Yes (1) 
No 
No 
Yes (1) 
No 
Yes (1) 

Unit 
means 

unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 

Individual 
results 

unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 

 
 
Table 5: Results of the statistical evaluation of the homogeneity studies of ERM-EB074C; n 
= number of outliers; T = number of series with an analytical trend. 

ERM-
EB074C 

Analyte 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

Analytical trends 

Significant at 95% 
confidence level 
(T) 
No 
Yes (1) 
No 
Yes (1) 
Yes (1) 
Yes (1) 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 

Between analytical run 
difference 
Tested with one way ANOVA 
Significant difference at 95% 
confidence level 
(F-test) 
No 
Yes 
Yes 
Yes 
No 
Yes 
No 
Yes 
No 
Yes 
No 
No 
Yes 
Yes 
No 
No 
No 
No 
Yes 
Yes 
Yes 
No 
No 
No 
Yes 
Yes 

Outliers at 99% 
confidence level 

Distribution 

Unit 
means 
(n) 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
Yes (1) 
No 
No 
No 
No 
No 
No 
No 
No 
No 

Individual 
results 
(n) 
No 
Yes (1) 
No 
Yes (1) 
No 
Yes (2) 
No 
No 
Yes (1) 
Yes (1) 
No 
Yes (1) 
No 
No 
No 
No 
Yes (1) 
No 
No 
Yes (1) 
No 
No 
Yes (1) 
No 
No 
Yes (1) 

Unit 
means 

unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 

Individual 
results 

unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 
unimodal 

No outlying means were detected at the 99 % confidence level except for Ag mass fraction in 
ERM-EB074A,  for  Pb  and  Si  mass  fraction  in  ERM-EB074B  and  for  Al,  Fe  and  Pb  mass 
fraction in ERM-EB074C. Some outlying individual results were detected. Since no technical 
reason for the outliers could be found, all the data were retained for statistical analysis.  

4.1.2  Evaluation of the trend or segregation within-billet 
The normalised datasets of ERM-EB074A study were used to detect significant trend within-
billet.  Fifteen  units  of  ERM-EB074A  were  selected  using  a  random  stratified  sampling 
scheme covering half billet for the within-billet homogeneity test. Regression analyses were 
performed using these 15 units to evaluate potential trends within-billet.  No outlying means 
were detected at the 99 % confidence level in the datasets used for within-billet homogeneity 
study. 

Regression  analyses  were  performed  using  these  nine  units  to  evaluate  potential  trends 
within the billet. No trends in the billet were visible on the 95 % confidence level for Ag, Al, 
As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, O, P, S, Sb, Se, Si, Sn, Te, Ti, W, Zn, Zr. 
A significant trend within billet was detected for Pb on the 95 % confidence level. 

For  Pb  ,  where  the  trend  in  the  billet  (segregation)  was  significant  at  the  95  %  confidence 
level,  the  uncertainty  was  assessed  in  a  different  way.  Here,  urec  was  estimated  using  a 
rectangular distribution between the highest and lowest unit mean. The corrected uncertainty 
in those cases where there was a significant trend in the filling sequence is given in Equation 
3. 

u

rec

,

rel

=

highest re

sult - low

est result

2

3

y 

y  

mean of all results of the homogeneity study 

Equation 3 

17 

 
(cid:215)
(cid:215)
 
This applies for Pb for ERM-EB074A, B and C. 

4.1.3  Between-billet inhomogeneity quantification for ERM-EB074A 
ERM-EB074A  was  the  only  format  produced  using  different  billets  (two  billets).  The 
Significance  of  the  between-billet  difference  was  evaluated  using  the  results  of  the  ERM-
EB074A homogeneity study. 

In the ERM-EB074A homogeneity study, 15 and 20 units were selected from each of the two 
billets. Quantification of between billet inhomogeneity was accomplished using the analytical 
trend corrected dataset by the mean of a two-way ANOVA. A two-way ANOVA can separate 
the  between-run  variation  (sR),  the  between-billet  variation  (sbb,billet)  and  the  within-billet 
variation  (swb,billet).  An  F-test  was  used  to  determine  if  the  variance  due  to  the  billets  is 
significant on a 95 % confidence level. For Ag, Co, Cr, Fe, Mn Ni, O, Pb, S, Si, Sn and Zn, 
the difference between billets was significant. The data do not follow a unimodal distribution 
for Ag, Co, Cr, Fe, Mn Ni, O, Pb, S, Si, Sn and Zn mass fraction in ERM-EB074A. Therefore, 
urec,rel  was  estimated  using  a  rectangular  distribution  between  the  highest  and  lowest  unit 
mean [12]. The uncertainty in those cases is given as 

u

rec

,

rel

=

highest re

sult - low

est result

2

3

y 

y  

mean of all results of the homogeneity study 

The results of these evaluations are listed in Table 6. 

Equation 4 

4.1.4  Between-unit inhomogeneity quantification 
Quantification  of  between-unit  inhomogeneity  was  accomplished  using  the  analytical  trend 
corrected  dataset  by  two-way  ANOVA,  which  can  separate  the  between-run  variation  (sR), 
the between-unit variation (sbb) and the within-unit variation (swb). The latter is equivalent to 
the method repeatability if the individual samples are representative of the whole unit.  

Evaluation  by  ANOVA  requires  unit  means  that  follow  at  least  a  unimodal  distribution  and 
results for each unit that follow unimodal distributions with approximately the same standard 
deviations.  Distribution  of  the  unit  means  was  visually  tested  using  histograms  and  normal 
probability  plots.  Minor  deviations  from  unimodality  of  the  individual  values  do  not 
significantly affect the estimate of between-unit standard deviations.  

Recall  that  sbb,rel  and  swb,rel  are  estimates  of  the  true  standard  deviations  and,  therefore, 
subject to random fluctuations. Therefore, the mean square between groups (MSbetween) can 
be  smaller  than  the  mean  squares  within  groups  (MSwithin),  resulting  in  negative  arguments 
under the square root used for the estimation of the between-unit variation, whereas the true 
variation cannot be lower than zero. In this case, u*
bb, the maximum inhomogeneity that could 
be hidden by method repeatability, was calculated as described by Linsinger et al. [15]. u*
bb is 
comparable  to  the  limit  of  detection  of  an  analytical  method,  yielding  the  maximum 
inhomogeneity that might be undetected by the given study setup.  

Analysis of variance applied to a randomised block design with one observation per unit per 
run  leads  to  a  between-run  mean  square  MSR  together  with  a  between-unit  mean  square 
MSbetween,  and  a  residual  mean  square  MSwithin.  The  residual  mean  square  MSwithin  is  an 
unbiased estimate of the repeatability variance 2
rs . The between-unit standard deviation sbb is 
calculated  as  described  in  equation  5.  Method  repeatability  (swb,rel),  between–unit  standard 
deviation (sbb,rel) and u*

bb,rel were calculated as:  

18 

 
(cid:215)
(cid:215)
  
 
s

,wb

rel

=

MS

within

y 

s

,bb

rel

=

u

*
,bb

rel

=

MS

between

MS

within

n
y

MS
within
n

4

ν

2

MSwithin

y

Equation 4 

Equation 5 

Equation 6 

MSwithin 

mean square within a unit from an ANOVA  

MSbetween  mean squares between-unit from an ANOVA 

y  

n 

ν

MSwithin

mean of all results of the homogeneity study 

number of analytical runs 

degrees of freedom of MSwithin  

For ERM-EB074A, the homogeneity study showed unimodal distribution and no outlying unit 
means  or  trends  within-billet  for  As,  Al,  Au,  Be,  Bi,  Cd,  In,  Mg,  P,  Sb,  Se,  Te,  Ti  and  Zr. 
Therefore, the between-unit standard deviation can be used as estimate of ubb. As u*
bb sets 
the limits of the study to detect inhomogeneity, the larger value of sbb and u*
bb is adopted as 
the uncertainty contribution to account for potential inhomogeneity. 

For  ERM-EB074B  and  C,  the  homogeneity  study  showed  unimodal  distribution,  no  outlying 
unit means or trends within-billet for all elements except the Pb and Si mass fraction in ERM-
EB074B and the Al, Fe and Pb mass fraction in ERM-EB074C. Therefore, the between-unit 
standard  deviation  can  be  used  as  estimate  of  ubb.  As  u*
bb  sets  the  limits  of  the  study  to 
detect  inhomogeneity,  the  larger  value  of  sbb  and  u*
bb  is  adopted  as  the  uncertainty 
contribution to account for potential inhomogeneity. 

However, a different approach was adopted for the Ag mass fraction of ERM-EB074A, for the 
Pb and Si mass fractions of ERM-EB074B and for the  Al, Fe and Pb mass fractions of ERM-
EB074C  for  which  one  outlying  unit  mean  was  detected.  In  these  cases  between-unit 
inhomogeneity was modelled as a rectangular distribution limited by the largest outlying unit 
mean, and the rectangular standard uncertainty of homogeneity was estimated by: 

=

u rec

outlier

y

3

y

Equation 7 

y  

mean of all results of the homogeneity study 

It should be mentioned that the outlying unit means are a result of the presence of outlying 
individual values and do not necessarily reflect the real distribution of these elements in the 
material. 

The  results  of  the  evaluation  of  the  between-unit  variation  in  ERM-EB074A,  B  and  C  are 
summarised  in  Tables  6-8.  The  resulting  values  from  the  above  equations  were  converted 
into relative uncertainties.  

19 

 
 
-
 
 
 
(cid:215)
-
 
 
 
 
Table 6: Results of the homogeneity study of ERM-EB074A 

ERM-EB074A 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

swb,rel 
[%] 
2.76 
7.43 
3.83 
3.07 
11.71 
6.62 
5.50 
2.54 
2.92 
1.69 
7.66 
6.82 
1.77 
3.79 
12.80 
7.68 
6.44 
5.25 
4.69 
5.04 
6.65 
5.23 
5.54 
5.66 
5.33 
7.13 

sbb,rel 
[%] 
0.63 
3.23 
0.29 
0.57 
3.60 
n.c. 1) 
0.95 
1.07 
1.86 
1.67 
n.c. 1) 
1.74 
1.25 
6.28 
7.23 
1.73 
6.78 
3.67 
n.c. 1) 
0.94 
5.29 
12.24 
0.31 
3.03 
5.57 
2.83 

1) n.c.: cannot be calculated as MSbetween < MSwithin 
2) n.a.: not applicable 

u*
bb,rel 
[%] 
0.52 
1.40 
0.72 
0.58 
2.19 
1.24 
1.03 
0.48 
0.55 
0.32 
1.43 
1.28 
0.33 
0.71 
2.65 
1.44 
1.21 
0.98 
0.88 
0.94 
1.25 
0.98 
1.04 
1.06 
1.00 
1.33 

urec,rel 
[%] 
2.06 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
2.21 
2.46 
2.15 
n.a. 2) 
n.a. 2) 
1.91 
6.28 
13.01 
n.a. 2) 
7.13 
5.09 
n.a. 2) 
n.a. 2) 
9.60 
9.54 
n.a. 2) 
n.a. 2) 
5.61 
n.a. 2) 

ubb,rel 
[%] 
2.06 
3.23 
0.72 
0.58 
3.60 
1.24 
1.03 
2.21 
2.46 
2.15 
1.43 
1.74 
1.91 
6.28 
13.01 
1.73 
7.13 
5.09 
0.88 
0.94 
9.60 
12.24 
1.04 
3.03 
5.61 
2.83 

20 

 
 
 
Table 7: Results of the homogeneity study of ERM-EB074B 

ERM-EB074B 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

swb,rel 
[%] 
2.70 
6.82 
2.71 
3.85 
8.78 
7.13 
5.15 
2.42 
3.25 
2.25 
6.73 
5.66 
1.71 
4.13 
13.39 
6.09 
6.53 
5.18 
5.17 
5.37 
16.23 
4.99 
5.58 
4.36 
3.77 
6.60 

sbb,rel 
[%] 
0.58 
2.89 
0.31 
n.c. 1) 
n.c. 1) 
n.c. 1) 
1.08 
0.75 
0.54 
0.64 
1.95 
n.c. 1) 
n.c. 1) 
2.91 
7.78 
2.17 
1.90 
1.73 
0.52 
1.41 
5.02 
1.45 
1.70 
1.90 
1.49 
2.97 

u*
bb,rel 
[%] 
0.54 
1.37 
0.54 
0.77 
1.76 
1.43 
1.03 
0.48 
0.65 
0.45 
1.35 
1.13 
0.34 
0.83 
3.42 
1.22 
1.31 
1.04 
1.03 
1.07 
3.29 
1.00 
1.12 
0.87 
0.75 
1.33 

1) n.c.: cannot be calculated as MSbetween < MSwithin 
2) n.a.: not applicable 

Table 8: Results of the homogeneity study of ERM-EB074C 

ERM-EB074C 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

swb,rel 
[%] 
5.68 
24.01 
6.74 
14.53 
30.53 
18.66 
6.99 
10.70 
12.29 
5.67 
6.69 
12.92 
8.35 
13.75 
9.88 
23.57 
3.60 
19.87 
9.55 
19.62 
13.19 
8.41 
14.11 
11.93 
15.04 
10.31 

sbb,rel 
[%] 
1.46 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
1.77 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
5.01 
5.44 
0.70 
5.69 
n.c. 1) 
n.c. 1) 
n.c. 1) 
n.c. 1) 
4.10 
6.58 
1.22 
2.39 

1) n.c.: cannot be calculated as MSbetween < MSwithin 
2) n.a.: not applicable 

21 

u*
bb,rel 
[%] 
1.12 
4.73 
1.32 
2.85 
6.00 
3.68 
1.37 
2.11 
2.41 
1.12 
1.31 
2.54 
1.66 
2.70 
1.60 
4.63 
0.71 
3.22 
1.88 
3.85 
2.59 
1.65 
2.77 
2.34 
2.96 
2.03 

urec,rel 
[%] 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
4.48 
n.a. 2) 
n.a. 2) 
n.a. 2) 
12.74 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 

urec,rel 
[%] 
n.a. 2) 
17.56 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
5.21 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
3.05 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 

ubb,rel 
[%] 
0.58 
2.89 
0.54 
0.77 
1.76 
1.43 
1.08 
0.75 
0.65 
0.64 
1.95 
1.13 
0.34 
2.91 
7.78 
2.17 
4.48 
1.73 
1.03 
1.41 
12.74 
1.45 
1.70 
1.90 
1.49 
2.97 

ubb,rel 
[%] 
1.46 
17.56 
1.32 
2.85 
6.00 
3.68 
1.37 
2.11 
2.41 
5.21 
1.31 
2.54 
1.66 
2.70 
5.01 
5.44 
3.05 
5.69 
1.88 
3.85 
2.59 
1.65 
4.10 
6.58 
2.96 
2.39 

 
 
The  three  formats  were  produced  from  the  same  melt;  it  was  decided  to  assign  one 
uncertainty contribution to ERM-EB074. It is detailed in Section 4.3. 

4.2  Within-unit homogeneity and minimum sample intake 

The within-unit homogeneity is closely correlated to the minimum sample intake. Due to this 
correlation, individual aliquots of a material will not contain the same amount of analyte. The 
minimum sample intake is the minimum amount of sample that is representative of the whole 
unit and thus can be used in an analysis. Sample sizes greater than or equal to the minimum 
sample intake guarantee the certified value within its stated uncertainty.  

4.2.1  Radial within-unit homogeneity for ERM-EB074A 
For ERM-EB074A which was suspected of being inhomogeneous across the face of a disk, 
perhaps due to the migration of certain elements during cooling of casting, face homogeneity 
was tested using solid sampling techniques that consume microgram quantities of material. A 
mapping  technique  was  applied  in  which  analytical  spots  were  selected  across  the  face  of 
the discs.  

For  the  radial  within  unit  homogeneity  study,  one  unit  of  ERM-EB074A  was  selected 
randomly  and  cut  into four  thinner  discs  to test four  different faces for the  radial  within-unit 
homogeneity test.  

For  the  radial  within  unit  homogeneity  study,  one  unit  of  ERM-EB074A  was  selected 
randomly  and  cut  into  four  thinner  discs  (~10  mm  thick)  to  test  four  different  faces  for  the 
radial within-unit homogeneity test. The discs were prepared according to the instructions for 
use, including mechanical cleaning of the surface.  

The  disc  face  was  divided  into  three  areas:  central,  intermediate  and  external  (Figure  2B). 
Three, four and six independent locations were analysed from the central, intermediate and 
external  areas  respectively.  Analyses  were  performed  by  spark-OES for  Ag,  Al,  As,  Be,  Bi, 
Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Ti, Zn, Zr mass fraction. 

1 cm 

External 
area 

A 

Central 
area 

B 

1 cm 

External 
area 

Intermediate 
area 

Central 
area 

Figure 2: Figure 2A: Localisation of the two different areas for the radial within-unit 
homogeneity study by GD-MS; Figure 2B: localisation of the three different areas for 
radial within-unit homogeneity study by spark-OES. The red points represent the 
number of spot analysis per area. 

For Au, In and Te, the within-unit homogeneity study was performed by GD-MS. The analysis 
area is larger for GD-MS than for spark-OES. Therefore, it was only possible to perform one 
analysis in the central area and six analyses in the external area. No analyses were made in 

22 

 
 
              
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
the  intermediate  area  (Figure  2A).  One  and  six  independent  locations  from  central  and 
external areas were analysed by GD-MS for Au, In and Te.  

The  measurements  were  performed  in  a  randomised  block  design  because  the  number  of 
replicates on all units (52 analyses) could not be included in a single run due to instrumental 
constraints (drift towards the end of a long run). Improved precision (measured as the within-
unit standard deviation) was obtained using several short runs in a randomised block design. 

In the randomised block design for 13 independent analyses on each of four faces of ERM-
EB074A,  four  measurement  sequences  (one  measurement  sequence  per  face)  were 
planned, with each spot measured once in random order. Runs were randomised individually 
in a manner to be able to separate a potential analytical drift from any radial trend in the disc.  

Regression analysis and F-test (or T-test for Au, In and Te) were used to estimate the radial 
within-unit homogeneity independently of the analytical sequence effect. 

The data evaluation was performed in the following order: 

1 – Trends in analytical run / correction for significant trends  

Regression  analyses  were  done  to  evaluate  potential  trends  in  each  analytical  run.  Some 
significant (95 % confidence level) trends in the analytical sequence were visible, pointing at 
a  signal  drift  in  the  analytical  system  (Table  9).  As  the  analytical  sequence  and  the  unit 
numbers  were  not  correlated, trends  significant  on  a  95  %  confidence  level  were  corrected 
as explained in equation 1.  

2 – Evaluation of between analytical run effect / Normalisation of dataset (if necessary) 

The  analytical  trend-corrected  dataset  was  evaluated  for  significant  differences  between 
analytical  runs  (95  %  confidence  level)  using  one-way  ANOVA.  Significant  differences 
between  analytical  runs  were  observed  on  the  95  %  confidence  level  for  all  elements  in 
ERM-EB074A except As, Be, Co, Mn, Ni, Se, Sn, Zn and Zr (Table 9). As it is assumed that 
run effects and unit effects were independent, differences between analytical runs on 95 % 
confidence level were corrected as explained in equation 2.  

3 – Statistical evaluation of the datasets 

The  normalised  datasets  were  tested  for  consistency  using  Grubbs  outlier  tests  on  a 
confidence level of 99 % on the individual results and the unit means (Table 9).  

No  outlying  means  were  detected  on  the  99  %  confidence  level  except  for  In.  Since  no 
technical  reason  for  the  outliers  could  be  found,  all  the  data  were  retained  for  statistical 
analysis. 

23 

 
 
 
Table 9: Results of the statistical evaluation of the radial within-unit homogeneity study 
of ERM-EB074A; T = number of series with analytical trend 

ERM-
EB074A 

Analyte 

Ag 
Al 
As 
Au1) 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In1) 
Mg 
Mn 
Ni 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te1) 
Ti 
Zn 
Zr 

Analytical trends 

Significant at 
95% confidence 
level 
(T) 
Yes (1) 
No 
Yes (1) 
No 
No 
Yes (1) 
Yes (2) 
Yes (1) 
Yes (1) 
Yes (1) 
No 
Yes (1) 
Yes (2) 
No 
Yes (2) 
Yes (1) 
No 
No 
Yes (1) 
Yes (1) 
Yes (2) 
No 
No 
No 
No 

Between 
analytical run 
difference 
Significant 
difference at 
95% confidence 
level 
Yes 
Yes 
No 
Yes 
No 
Yes 
Yes 
No 
Yes 
Yes 
Yes 
Yes 
No 
No 
Yes 
Yes 
Yes 
Yes 
No 
Yes 
No 
Yes 
Yes 
No 
No 

Outliers at 99% 
confidence level 

Trend / inhomogeneity 

Inhomogeneity 
uncertainty 

Unit 
means 

Individual 
results 

None 
None 
None 
None 
None 
None 
None 
None 
None 
None 
Yes (1) 
None 
None 
None 
None 
None 
None 
None 
None 
None 
None 
No 
No 
None 
None 

None 
None 
None 
None 
None 
None 
None 
None 
None 
None 
Yes (1) 
Yes (1) 
None 
Yes (2) 
None 
None 
None 
None 
None 
None 
None 
Yes (1) 
None 
None 
None 

Radial linear 
trend at 95% 
confidence 
level 
No 
Yes 
No 
n.a. 2) 
No 
No 
No 
No 
No 
No 
n.a. 2) 
No 
Yes 
No 
No 
No 
No 
No 
No 
No 
No 
n.a. 2) 
No 
No 
Yes 

Between area 
difference at 
95% confidence 
level 
Yes (F-test) 
No (F-test) 
No (F-test) 
Yes (T-test) 
Yes (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
Yes (F-test) 
Yes (T-test) 
Yes (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
No (F-test) 
Yes (T-test) 
No (F-test) 
No (F-test) 
Yes (F-test) 

urec,rel 
[%] 

1.23 
0.52 
n.a. 2) 
1.85 
1.03 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
2.12 
6.35 
0.87 
0.27 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
n.a. 2) 
5.11 
n.a. 2) 
n.a. 2) 
1.85 

1) Au, In and Te were tested using GD-MS and only on central and external area 
2) n.a.: not applicable  
Regression  analyses  were  performed  to  evaluate  potential  radial  trends  within-unit.  No 
trends within the unit face were visible on a 95 % confidence level for all elements except Al, 
Mn  and  Zr,  where  significant  radial  trends  within  unit  (decrease  or  increase  from  centre  to 
external area) were detected (95 % confidence level). 

An  F-test  was  used  to  determine  if  a  significant  difference  is  observed  between  the  three 
areas  on  the  95  %  confidence  level.  For  Be  Fe,  Mg  and  Zr,  the  difference  between  face 
areas was significant on a 95% confidence level. 

For  Au,  In  and  Te,  a  T-test  was  used  to  determine  if  a  significant  difference  is  observed 
between the central and external areas on a 95 % confidence level. For Au, In and Te, the 
difference between central and external area was significant on a 95 % confidence level. 

For Al, Au, Be, Fe, In, Mg, Mn, Te and Zr, inhomogeneity was observed along the radial axis 
of ERM-EB074A face. Therefore, urec was estimated using a rectangular distribution between 
the highest and lowest face area mean [12]. The uncertainty in those cases is given in: 

u

rec

,

rel

=

highest re

sult - low

est result

2

3

y 

y  

mean of all results of the homogeneity study 

Equation 3 

The results of the study are summarised in Table 9. Central, intermediate and external area 
mean values are given in Annex B. 

The radial inhomogeneity was tested and found not significant for As, Bi, Cd, Co, Cr, Ni, P, 
Pb, S, Sb, Se, Si, Ti and Zn. Significant radial inhomogeneity was observed for Ag, Al, Au, 

24 

 
(cid:215)
(cid:215)
  
Be,  Fe,  In,  Mg,  Mn,  Sn,  Te  and  Zr  and  estimated  using  rectangular  distribution.  The 
uncertainty  contribution  from  radial  within-unit  uncertainty  is  below  2.5%  for  all  elements 
(except In and Te) which is considered sufficiently small to make the material useful. 

For In and Te, the central area of ERM-EB074A showed significantly lower results than the 
external area. The radial within-unit uncertainty is estimated to 5.1 % and 6.4 %. The within-
unit  contribution  is  not  negligible  and  it  will  be  included  in  the  final  uncertainty  budget  of 
ERM-EB074A, B and C. 

4.2.2  Minimum sample intake estimation 
Homogeneity/stability experiments were performed using GD-MS and spark-OES technique 
for Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, 
W, Zn, Zr. The sample intake of these methods gives acceptable repeatability, demonstrating 
that  the  within-unit  inhomogeneity  does  not  contribute  to  analytical  variation  at  this  sample 
intake.  

Quantification of the sample intake for GD-MS and spark-OES is difficult, as both are direct 
surface sampling and analysis methods. In contrast, the minimum sample intake required for 
ICP-MS is significantly larger and quantifiable. Based on the acceptable repeatability of the 
direct  surface  sampling  and  analysis  methods,  the  sample  intake  of  those  methods  meets 
the minimum sample intake requirements for ERM-EB074A, B and C. 

A rough estimation was done for each technique to estimate the sample intake used for GD-
MS and spark-OES.. For spark-OES, a spot analysis of 4 mm diameter, a depth of 0.1 mm 
and  the  copper  density  of  8.96  g/cm3  was  assumed.  For  GD-MS,  a  spot  analysis  of  8  mm 
diameter, a depth of 0.05 mm and the copper density of 8.96 g/cm3 was assumed. Therefore, 
the sample intake of spark-OES was estimated to approximately 11 mg and 20 mg for GD-
MS.  Using  the  rough  estimation  of  GD-MS  and  spark-OES  sample  intake,  the  following 
minimum sample intakes are derived: 

- Sample intake of 10 mg for Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, Hg, Mg, Mn, Ni, P, Pb, S, Sb, 
Se, Si, Sn, Ti, W, Zn, Zr 

- Sample intake of 20 mg for Au, In and Te. 

Results by laser ablation (data not shown) indicate that the material is not homogeneous on 
the  micrometre  scale.  Results  from  several  points  need  to  be  pooled  when  using  laser 
ablation 

4.3  Uncertainty of homogeneity of ERM-EB074A, B and C 

The  three  formats  are  produced  from  the  same  melt;  it  was  decided  to  assign  the  same 
uncertainty contribution to all three formats. 

For ERM-EB074A, the final homogeneity uncertainty is the combination of the ubb,rel and the 
uwithin-rad,rel.  

The largest ubb,rel of ERM-EB074A, B and C is adopted as the uncertainty of inhomogeneity 
of  ERM-EB074  except  when  the  uncertainty  contribution  of  ERM-EB074C  corresponds  to 
u*

bb,rel for the following reason:  

The methods used to assess homogeneity (Table 2) were different for ERM-EB074A, B (GD-
MS)  and  ERM-EB074C  (ICP-MS  /  ICP-OES).  The  GD-MS  method  used  for  ERM-EB074A 
and B provided better repeatability and lower u*
bb,rel than the method used for ERM-EB074C. 
It  should  be  noticed  that  in  all  cases  except  for  Ag,  Fe,  O,  P,  Pb,  S,  Te,  Ti  and  Zr,  the 
homogeneity uncertainty assigned to ERM-EB074C corresponds to u*
bb,rel, i.e. only an upper 
limit  of  potential  inhomogeneity  could  be  calculated. In  order to  avoid  overestimation  of  the 
uncertainty of homogeneity due to the method repeatability, u*
bb,rel of ERM-EB074C was not 
used for the estimation of ubb,rel of ERM-EB074. The combined homogeneity uncertainties are 
given in Table 10. 

25 

 
The uncertainty of homogeneity of the Ag, Al, As, Au, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, 
P,  Pb,  S,  Sb,  Se,  Sb,  Sn,  Te,  Ti,  W  and  Zn  mass  fractions  in  ERM-EB074A,  B  and  C  is 
sufficient  small  to  make  the  material  useful.  The  homogeneity  study  showed  significant 
inhomogeneity  for  the  Al,  O  and  Si  and  Sn  mass  fractions,  which  limits  the  use  of  the 
materials as reference materials for these elements.  

Table 10: Summary of the homogeneity study for ERM-EB074. The data shown in the 
right  column  were  used  as  estimate  of  the  uncertainty  of  homogeneity  for  all  three 
formats. 

ERM-EB074A 

Analyte 

ubb,rel 
[%] 

uwithin-rad,,rel 
[%] 

Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

urec,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
urec,rel 
urec,rel 
urec,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
sbb,rel 
urec,rel 
sbb,rel 
urec,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
urec,rel 
urec,rel 
u*
bb,rel 
sbb,rel 
urec,rel 
sbb,rel 

2.06 
3.23 
0.72 
0.58 
3.60 
1.24 
1.03 
2.21 
2.46 
2.15 
1.43 
1.74 
1.91 
6.28 
13.01 
1.73 
7.13 
5.09 
0.88 
0.94 
9.60 
12.24 
1.04 
3.03 
5.61 
2.83 

1) n.a.: not applicable 

5  Stability 

1.23 
0.52 
n.a. 1) 
1.85 
1.03 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
2.12 
6.35 
0.87 
0.27 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
n.a. 1) 
5.11 
n.a. 1) 
n.a. 1) 
n.a. 1) 
1.23 

Combined 
ubb,rel 
[%] 
2.40 
3.27 
0.72 
1.94 
3.75 
1.24 
1.03 
2.21 
2.46 
3.02 
6.51 
1.94 
1.93 
6.28 
13.01 
1.73 
7.13 
5.09 
0.88 
0.94 
9.60 
12.24 
5.22 
3.03 
5.61 
3.38 

ERM-EB074B 
ubb,rel 
[%] 

ERM-EB074C 
ubb,rel 
[%] 

ERM-EB074 
ubb,rel 
[%] 

sbb,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
sbb,rel 
urec,rel 
sbb,rel 
u*
bb,rel 
sbb,rel 
urec,rel 
sbb,rel 
sbb,rel 
sbb,rel 
sbb,rel 
sbb,rel 

0.58 
2.89 
0.54 
0.77 
1.76 
1.43 
1.08 
0.75 
0.65 
0.64 
1.95 
1.13 
0.34 
2.91 
7.78 
2.17 
4.48 
1.73 
1.03 
1.41 
12.74 
1.45 
1.70 
1.90 
1.49 
2.97 

sbb,rel 
urec,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
urec,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
urec,rel 
sbb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
u*
bb,rel 
sbb,rel 
sbb,rel 
u*
bb,rel 
sbb,rel 

1.46 
17.56 
1.32 
2.85 
6.00 
3.68 
1.37 
2.11 
2.41 
5.21 
1.31 
2.54 
1.66 
2.70 
5.01 
5.44 
3.05 
5.69 
1.88 
3.85 
2.59 
1.65 
4.10 
6.58 
2.96 
2.39 

2.40 
17.56 
0.72 
1.94 
3.75 
1.43 
1.08 
2.21 
2.46 
5.21 
6.51 
1.94 
1.93 
6.28 
13.01 
5.44 
7.13 
5.69 
1.03 
1.41 
12.74 
12.24 
5.22 
6.58 
5.61 
3.38 

Stability assessment is necessary to establish conditions for storage (long-term stability) as 
well  as  conditions  for  dispatch  to  the  customers  (short-term  stability).  During  transport, 
especially  in  the  summer,  temperatures  up  to  60  °C  could  be  reached  and  stability  under 
these conditions must be demonstrated if transport at ambient temperature is to be applied. 

Metallic copper is stable over time and temperature as archaeological artefacts and antique 
copper  cooking  ware  demonstrate:  they  remain  unchanged  without  special  precautions  for 
hondreds and tousands of years. 

Copper  has  good  chemical  resistance  to  degradation  under  normal  storage  and  handling 
conditions.  However,  copper  is  subject  to  surface  oxidation  over  time.  Before  using  ERM-
EB074A, B and C, it is mandatory to remove the oxide layer that may appear on the surface 
of the material as explained in section 9.3 Instructions for use. 

The  stability  of  trace  elements  in  electrolytic  copper  was  studied  using  data  from  BCR-075 
[12]. BCR-075 was produced and certified in 1992 and used in this investigation as a quality 

26 

 
control material for evaluation of the characterisation results. The BCR-075 results reported 
in  this  study  confirmed  the  certified  values,  taking  into  consideration  the  measurement 
uncertainty and substantiated the stability of trace elements in copper.  

The trace element mass fractions in ERM-EB074A, B and C are therefore considered stable 
under normal dispatch conditions (up to 60 °C).  

Based on previous experience, a validity period of the certificate for ERM-EB074A, B and C 
of 10 years is set. 

Recommended storage and transport conditions: 

The  material  can  be  transported  under  ambient  conditions  without  special  precautions  and 
stored at a temperature not exceeding 18 –  5 °C. Uncertainties due to storage and shipment 
conditions are considered negligible regarding the material property. 

After  the  certification  campaign,  the  material  will  be  subjected  to  IRMM's  regular  stability 
monitoring programme to control its further stability. 

6  Characterisation 

The material characterisation is the process of determining the property values of a reference 
material.  The  material  characterisation  was  based  on  an  intercomparison  of  expert 
laboratories. The Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, H, Hg, In, Mg, Mn, Ni, O, P, Pb, S, 
Sb,  Se,  Si,  Sn,  Te,  Ti,  W,  Zn  and  Zr  mass  fractions  of  the  ERM-EB074A,  B  and  C  were 
determined  in  different  laboratories  that  applied  different  measurement  procedures  to 
demonstrate  the  absence  of  a  measurement  bias.  This  approach  aims  at  randomisation  of 
laboratory  bias.  The  intercomparison  of  laboratories  seeks  to  reduce  the  combined 
uncertainty. 

6.1  Selection of participants 

Eighteen  laboratories  were  selected  based  on  criteria  that  comprised  both  technical 
competence  and  quality  management  aspects.  Each  participant  was  required  to  operate  a 
quality system and to deliver documented evidence of its laboratory proficiency in the field of 
element  measurements  in  relevant  matrices  by  submitting  results  for  intercomparison 
exercises or method validation reports. Having a formal accreditation was not mandatory, but 
meeting  the  requirements  of  ISO/IEC  17025  was  obligatory.  Where  the  scope  of 
accreditation  covers  measurement,,  the  accreditation  number  is  stated  in  the  list  of 
participants (Section 0). 

6.2  Study setup  

Each laboratory received two units of ERM-EB074A, B and C and was requested to provide 
at least three independent results per unit. Several analytical techniques (i.e. GD-MS, spark-
OES,  DC-arc-OES)  were  not  able  to  analyse  trace  elements  in  all  three  formats  due  to 
instrument constraints (sample size). Each laboratory was required to provide the results of 
at  least  three  independent  results  on  each  of the  two  units  for  one format  analysed  for  the 
following elements: Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, H, Hg, In, Mg, Mn, Ni, O, P, Pb, S, 
Sb, Se, Si, Sn, Te, Ti, W, Zn and Zr. 

The  units  for  material  characterisation  were  selected  using  a  random  stratified  sampling 
scheme and covered the whole batch. The sample preparations and measurements had to 
be  spread  over  at  least  two  days  to  ensure  intermediate  precision  conditions.  An 
independent calibration was performed for each result.  

Each  participant  received  a  sample  of  BCR-075  as  a  blind  quality  control  (QC)  sample 
except for L13, which used BCR-075 for calibration. In this case, the calibration results were 
used to support the evaluation of the characterisation results. 

27 

 
Laboratories  were  also  requested  to  give  estimations  of  the  expanded  uncertainties  of  the 
mean value of the results. No approach for the estimation was prescribed, i.e. top-down and 
bottom-up  were  regarded  as  equally  valid  procedures.  These  uncertainties  were  used  to 
evaluate the dispersion of the laboratory results (Annex E). 

6.3  Methods used 

A variety of acid digestion (HCl, HNO3, HF), extraction methods (co-precipitation with yttrium) 
with  different  quantification  steps  (ICP-MS,  ICP-OES)  as  well  as  methods  without  sample 
preparation (combustion with IR quantification, GD-MS, LA-ICP-MS, IGF-IR, INAA or spark-
OES)  were  used  to  characterise  the  material.  The  combination  of  results  from  methods 
based on entirely different principles mitigates undetected method bias. 

All  methods  used  during  the  characterisation  study  are  summarised  in  Annex  C.  The 
laboratory  code  (e.g.  L1)  is  a  random  number  and  does  not  correspond  to  the  order  of 
laboratories  in  Section  0.  The  lab-method  code  consists  of  a  number  assigned  to  each 
laboratory (e.g. L01) and abbreviation of the measurement method used (e.g. ICP-MS).  

6.4  Evaluation of results 

The characterisation campaign resulted in 3-15 datasets per element. All individual results of 
the  participants,  grouped  per  element  are  displayed  in  a  tabular  and/or  graphical  form  in 
Annex E.  

ERM-EB074A, B and C were considered homogeneous. Therefore, the results were pooled 
per  laboratory  independently  of  the  format  analysed  by  each  laboratory.  In  support  of  this 
assumption,  the  characterisation  study  was  performed  for  each  format  using  the  accepted 
datasets.  The  mean  of  laboratory  means  and  the  standard  deviation  of  the  mean  are 
presented in each format in Annex D, demonstrating the equivalence of the three formats. 

6.4.1  Technical evaluation 
The  data  obtained  were  first  checked  for  compliance  with  the  requested  analysis  protocol 
and their validity based  on technical reasons. The following criteria were considered during 
the evaluation:  

-  appropriate validation of the measurement procedure, 

- 

compliance  with  the  analysis  protocol:  sample  preparations  and  measurements 
performed on two days, and the analytical sequence, 

-  absence of values given as the below limit of detection or below limit of quantification, 

-  absence of technical problems (i.e. contamination, RSD > 50 %), 

-  method  performance,  i.e.  agreement  of  the  measurement  results  with  the  assigned 
value of the QC sample. As this test is performed using the respective uncertainties 
of  the  certified  values  and  the  measurement  uncertainties  estimated  by  the 
laboratory, it should be borne in mind that even national metrology institutes tend to 
underestimate their measurement uncertainties [16]. 

Most  technical  problems  were  inherent  in  one  laboratory  only,  except  data  for  Zr: 
Laboratories  not  using  HF  for  digestion  found  considerable  lower  values  for  Zr  than 
laboratories using HF. This can be explained by the fact that Zr precipitates in the absence of 
HF [17]. Laboratory 9 repeated the analysis using HF and obtained results between 4.3 and 
6.4 mg/kg,  confirming  that  this  is  not  a  laboratory-dependent  effect.  Therefore,  results  from 
digestions without HF were excluded for Zr. 

For Hg and W, most of the laboratories provided results below their reported LOD. In these 
specific cases, all data were retained to assign indicative values (Table 15). 

28 

 
Based  on  the  above  criteria,  the  following  datasets  were  rejected  as  not  technically  valid 
(Table 11). 

Table  11:  Datasets  that  showed  non-compliances  with  the  analysis  protocol  and 
technical specifications, and action taken 

Analyte 

Lab code 

Description of problem 

Action taken 

Ag 

Al 

As 

Au 

Bi 

Cd 

Co 

Cr 

Fe 

Mg 

Mn 

Ni 

O 

P 

Pb 

S 

Sb 

Se 

Si 

Sn 

Te 

Zn 

Zr 

L1, L12 
L6, L21 
L1, L4 
L9 
L18 
L8, L18 
L21 

L9 

L3, L4, L5, L18 
L2, L21 
L6, L21 
L18 
L6, L21 
L10, L15 L18 
L14, L15, L18 
L20, L21 
L1 
L7, L8, L9, L15, L21 
L10 
L1 
L20 
L5, L8, L11 and L18 
L21 
L4 
L1, L6, L8, L21 
L8, L18 

Deviating result on QC sample 
Report results below LOD 
Technical problem (RSD > 50%) 
Report results below LOD 
Technical problem (contamination) 
Deviating result on QC sample 
Report results below LOD 
Laboratory did not use aqua regia 
for digestion. 
Deviating result on QC sample 
Report results below LOD 
Report results below LOD  
Deviating result on QC sample 
Report results below LOD  
Deviating result on QC sample 
Deviating result on QC sample 
Report results below LOD 
Technical problem (contamination) 
Deviating result on QC sample 
Report results below LOD 
Report results below LOD 
Technical problem (blank) 
Deviating result on QC sample 
Report results below LOD  
Technical problem 
Report results below LOD  
Deviating result on QC sample 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

not used for evaluation 

L17 

Not compliant with analysis protocol 

not used for evaluation 

L1, L2, L6, L9 

Report results below LOD 

not used for evaluation 

L1, L2, L8, L18, L20, 
L21 
L4 
L9 
L2, L21 
L5 
L2, L7, L21 
L1, L4, L8, L11, L20 

Deviating result on QC sample 

not used for evaluation 

Technical problem (RSD > 50%) 
Report results below LOD 
Report results below LOD 
Deviating result on QC sample 
Report results below LOD 
Deviating result on QC sample 

not used for evaluation 

not used for evaluation 

not used for evaluation 

L1, L6, L9 

Report results below LOD 

not used for evaluation 

L21 

Report results below LOD 

not used for evaluation 

L9, L11 
L2, L7 
L6, L21 
L1, L8, L9 
L1, L8, L9, L11, L16 
L18 

Deviating result on QC sample 
Report results below LOD 
Report results below LOD 
Deviating result on QC sample 
Technical problem in digestion (HF 
not used for digestion) 

not used for evaluation 

not used for evaluation 

not used for evaluation 

29 

 
 
6.4.2  Statistical evaluation 
The  datasets  accepted  based  on  technical  reasons  were  tested  for  normality  of  dataset 
means  using  kurtosis/skewness  tests  and  normal  probability  plots.  Datasets  were  further 
evaluated  for  outlying  means  using  the  Grubbs  test  and  the  Cochran  test  for  outlying 
standard deviations, (both at a 99 % confidence level). Standard deviations within (swithin) and 
between (sbetween) laboratories were calculated using one-way ANOVA. The results of these 
evaluations are shown in Table 12. 

Table 12: Statistical evaluation of the technically accepted datasets for Ag, Al, As, Au, 
Be, Bi, Cd, Co, Cr, Fe, In, Mg, Mn, Ni, O, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn and Zr. p: 
number of technically valid datasets 

Analyte 

p 

Outliers 

Means 

Variances 

Normally 
distributed 

Statistical parameters  

Mean of the 
laboratory mean 
[mg/kg] 

s 
[mg/kg] 

sbetween 
[mg/kg] 

swithin 
[mg/kg] 

Ag 

Al 

As 

Au 

Be 

Bi 

Cd 

Co 

Cr 

Fe 

In 

Mg 

Mn 

Ni 

O 

P 

Pb 

S 

Sb 

Se 

Si 

Sn 

Te 

Ti 

Zn 

Zr 

15 

8 

15 

10 

12 

11 

12 

13 

12 

11 

14 

10 

9 

11 

3 

9 

11 

7 

16 

11 

5 

15 

14 

12 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

No 

Yes (L9) 

Yes (L5) 

Yes (L1) 

Yes (L16) 

Yes (L5) 

Yes (L16) 

Yes (L9) 

Yes (L2) 

Yes (L9) 

Yes (L2) 

Yes (L5) 

Yes (L4) 

No 

Yes (L7) 

No 

Yes (L4) 

Yes (L5) 

Yes (L7) 

Yes (L9) 

Yes (L9) 

No 

Yes (L1) 

Yes (L3) 

Yes (L5) 

14  Yes (L18) 

Yes (L4) 

7 

No 

Yes (L15) 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

No 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

Yes 

No 

Yes 

30 

1.027 

0.851 

1.234 

0.520 

0.311 

0.507 

0.402 

0.830 

0.373 

5.777 

0.494 

2.025 

0.931 

0.607 

8.411 

1.529 

2.675 

3.270 

0.567 

0.555 

1.240 

1.492 

0.505 

0.973 

2.189 

8.843 

0.073 

0.073 

0.095 

0.382 

0.409 

0.129 

0.144 

0.122 

0.092 

0.087 

0.081 

0.091 

0.080 

0.055 

0.056 

0.057 

0.059 

0.063 

0.063 

0.045 

0.034 

0.680 

0.604 

0.053 

0.051 

0.397 

0.394 

0.076 

0.075 

0.037 

0.031 

1.529 

1.435 

0.275 

0.265 

0.218 

0.220 

1.147 

1.105 

0.068 

0.064 

0.108 

0.105 

0.407 

0.368 

0.159 

0.151 

0.055 

0.051 

0.211 

0.199 

0.369 

0.396 

2.017 

2.060 

0.031 

0.038 

0.053 

0.037 

0.072 

0.117 

1.007 

0.055 

0.280 

0.070 

0.079 

1.232 

0.221 

0.208 

0.651 

0.042 

0.075 

0.122 

0.195 

0.066 

0.123 

0.326 

1.612 

 
 
The  laboratory  means  follow  a  normal  distribution.  None  of  the  data  contained  outlying 
means  except  Bi,  Pb  and  Zn.  The  statistical  evaluation  flagged  at  least  one  laboratory  as 
having an outlying variance for each analyte except for O and Si (Table 12). This reflects the 
fact  that  different  methods  have  distinctive  intrinsic  variability.  As  all  the  measurement 
methods were found to be technically sound, all the results were retained. The datasets are 
therefore consistent, and the mean of laboratory means is a good estimate of the true value. 

The statistical evaluation flagged laboratory L18 as an outlier for Zn mass fraction, although 
outlier  tests  do  not  take  uncertainty  information  into  consideration.  A  closer  investigation 
revealed that the difference between the mean value of laboratory L18 and the other results 
is  covered  by  the  measurement  uncertainty  of  laboratory  L18.  There  is,  therefore,  no 
evidence that the results of laboratory L18 deviate from the other results, and the result was 
retained.  

The statistical evaluation flagged laboratory L18 as an outlier for Bi and Pb mass fraction. As 
the difference between the mean value of laboratory L18 and the other results is not covered 
by  the  measurement  uncertainty  of  laboratory  L18,  there  is  evidence  of  a  significant 
disagreement of results. As the technical evaluation of results did not indicate any technical 
flaws  in  any  method,  there  is  no  reason  for  discarding  any  of  the  results.  As  there  is  the 
possibility that the results of laboratory L18 are the only correct ones, no value is assigned to 
Bi and Pb mass fraction. 

For  the  As,  Ti  mass  fractions,  a  closer  investigation  revealed  that  the  measurement 
uncertainty did not cover a difference between the assigned value and the L20 mean value.. 
However, the measurement uncertainty reported by L20 is considered underestimated (two 
times  the  standard  deviation).  Standard  deviations  among  laboratories  are  larger  than  the 
standard  deviation  within  laboratories,  showing  that  two  times  the  standard  deviation  of 
replicate measurements is unsuitable as an estimate of measurement uncertainty. Moreover, 
L20 mean value was not flagged as an outlier by the statistical test. Therefore, it was decided 
to retain the uncertainties of As and Ti as calculated in Table 13. 

For  the  Au  mass  fraction,  a  closer  investigation  revealed  that  a  difference  between  the 
assigned  value  and  the  L8  and  L20  mean  value  was  not  covered  by  the  measurement 
uncertainty.  However,  the  measurement  uncertainty  reported  by  L8  and  L20  most  likely 
underestimated,  as  it  is  based  only  on  the  experimental  standard  deviation.  Moreover,  the 
mean values of  L8 and L20 were not flagged as outliers by the statistical test. Therefore, it 
was decided to keep the Au uncertainty as calculated in Table 13. 

For  the  Be  mass  fraction,  a  closer  investigation  revealed  that  a  difference  between  the 
assigned  value  and  respectively,  the  L8 mean  value  was  not  covered  by  the  measurement 
uncertainty.  However,  the  measurement  uncertainty  reported  by  L8  and  L16  is  considered 
underestimated compared to other uncertainties for the ICP-MS method. Moreover, L8 mean 
value was not flagged as an outlier by the statistical test. Therefore, it was decided to keep 
the Be uncertainty as calculated in Table 13. 

For  the  Mg  and  Ti  mass  fraction,  a  closer  investigation  revealed  that  the  measurement 
uncertainty  did  not  cover  a  difference  between  the  assigned  value  and  L16  mean  value.. 
However,  the  measurement  uncertainty  reported  by  L16  is  considered  underestimated 
compared to other uncertainties for the ICP-MS method. Moreover, the L16 mean value was 
not flagged as an outlier by the statistical test. Therefore, it was decided to keep the Mg and 
Ti uncertainty as calculated in Table 13. 

The datasets were, therefore, consistent, and the mean of laboratory means is considered to 
be a good estimate of the true value. The uncertainty related to the characterisation (uchar) is 
estimated as the standard error of the mean of laboratory means (Table 13). 

31 

 
 
 
Table 13: Uncertainty of characterisation for Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, In, 
Mg, Mn, Ni, O, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, Zn and Zr. 

Analyte 

p 

Ag 

Al 

As 

Au 

Be 

Bi 

Cd 

Co 

Cr 

Fe 

In 

Mg 

Mn 

Ni 

O 

P 

Pb 

S 

Sb 

Se 

Si 

Sn 

Te 

Ti 

Zn 

Zr 

15 

8 

15 

10 

12 

11 

12 

13 

12 

11 

14 

10 

9 

11 

3 

9 

11 

7 

16 

11 

5 

15 

14 

12 

14 

7 

Mean 

s 

uchar 

uchar,rel 

[mg/kg] 

[mg/kg] 

[mg/kg] 

1.027 

0.851 

1.234 

0.073 

0.382 

0.144 

0.019 

0.135 

0.037 

0.520 

0.087 

0.027 

0.311 

0.507 

0.402 

0.830 

0.373 

5.777 

0.494 

2.025 

0.931 

0.607 

8.411 

1.529 

2.675 

3.270 

0.567 

0.555 

1.240 

1.492 

0.505 

0.973 

2.189 

8.843 

0.091 

0.055 

0.057 

0.063 

0.045 

0.680 

0.053 

0.397 

0.076 

0.037 

1.529 

0.275 

0.218 

1.147 

0.068 

0.108 

0.407 

0.159 

0.055 

0.211 

0.369 

2.017 

0.026 

0.017 

0.016 

0.017 

0.013 

0.205 

0.014 

0.126 

0.025 

0.011 

0.883 

0.092 

0.066 

0.434 

0.017 

0.032 

0.182 

0.041 

0.015 

0.061 

0.099 

0.762 

[%] 

1.82 

15.87 

3.02 

5.28 

8.42 

3.27 

4.06 

2.09 

3.47 

3.55 

2.89 

6.20 

2.71 

1.83 

10.50 

5.99 

2.45 

13.26 

3.01 

5.85 

14.68 

2.74 

2.90 

6.26 

4.51 

8.62 

32 

 
 
 
 
 
7  Value Assignment 

Certified, indicative and informative values were assigned. 

Certified values are values that fulfil the highest standards of accuracy. Procedures at IRMM 
require  pooling  of  not  less  than  6  datasets  to  assigned  certified  values.  Full  uncertainty 
budgets  following  the  'Guide  to  the  Expression  of  Uncertainty  in  Measurement'  [4]  were 
established.  

Indicative  values  are  values  where  either  the uncertainty  is  deemed  too large  or  where  too 
few  independent  datasets  were  available  to  allow  certification.  Uncertainties  are  evaluated 
according to the same rules as for certified values. 

Additional material information refers to values that were obtained in the course of the study. 
For example, results reported from only one or two laboratories or in cases where individual 
measurement uncertainty is high falls under this category.  

7.1  Certified values and their uncertainties 

The  unweighted  mean  of  the  means  of  the  accepted  datasets,  as  shown  in  Table  12  was 
assigned as certified value for each parameter.  

The  assigned  uncertainty  consists  of  uncertainties  related to  characterisation,  uchar  (Section 
0), potential between-unit inhomogeneity, ubb (Section 4.1), radial within unit inhomogeneity, 
uwithin-rad,rel (Section 4.3). The uncertainty related to stability during transport/long-term storage 
was estimated to be negligible. These different contributions were combined to estimate the 
expanded, relative uncertainty of the certified value (UCRM, rel) with a coverage factor k as:  

U

CRM,

rel

(cid:215)=
k

u

2
char,

rel

+

u

2
 bb,

rel

. 

Equation 2 

-  uchar,rel was estimated as described in Section 6, 

-  ubb,rel was estimated as described in Section 4.1, 

Because  of  the  sufficient  numbers  of  the  degrees  of  freedom  of  the  different  uncertainty 
contributions, a coverage factor k of 2 was applied, to obtain the expanded uncertainties. 

The certified values and their uncertainties are summarised in Table 14. 

33 

 
 
 
 
 
Table 14: Certified values and their uncertainties for ERM-EB074A, B and C 

Analyte 

Ag 

As 

Au 

Be 

Bi 

Cd 

Co 

Cr 

Fe 

In 

Mg 

Mn 

Ni 

P 

Pb 

Sb 

Se 

Te 

Ti 

Certified value 
[mg/kg] 1) 
1.03 

1.23 

0.52 

0.31 

0.51 

0.40 

0.83 

0.37 

5.8 

0.49 

2.03 

0.93 

0.61 

1.53 

2.7 

0.57 

0.55 

0.50 

0.97 

uchar, rel 
[%] 

1.82 

3.02 

5.28 

8.42 

3.27 

4.06 

2.09 

3.47 

3.55 

2.89 

6.20 

2.72 

1.83 

5.99 

2.46 

3.01 

5.85 

2.90 

6.26 

2.2 

Zn 
1) rounded certified value 
2) n.a.: not applicable 
3) Expanded (k = 2) and rounded uncertainty. 

4.51 

ubb, rel 
[%] 

2.40 

0.72 

1.94 

3.75 

1.43 

1.08 

2.21 

2.46 

5.21 

6.51 

1.94 

1.93 

6.28 

5.44 

7.13 

1.03 

1.41 

5.22 

6.58 

5.61 

UCRM, rel 
[%] 

6.02 

6.21 

11.24 

18.44 

7.14 

8.41 

6.08 

8.51 

12.61 

14.24 

13.00 

6.67 

13.09 

16.18 

15.08 

6.37 

12.02 

11.94 

18.17 

14.39 

UCRM 
[mg/kg] 3) 
0.07 

0.08 

0.06 

0.06 

0.04 

0.04 

0.06 

0.04 

0.8 

0.07 

0.27 

0.07 

0.08 

0.25 

0.4 

0.04 

0.07 

0.06 

0.18 

0.4 

7.2  Indicative values and their uncertainties 

Indicative values were assigned for Hg, S, Sn and W and Zr.  

For  Sn,  the  inhomogeneity  observed  between  units  leads  to  a  high  uncertainty  for  the  Sn 
mass  fraction  in  ERM-EB074A,  B  and  C.  However,  the  results  were  viewed  as  sufficiently 
trustworthy to assign indicative values.  

For  the  Hg  and  W  mass  fractions,  all  laboratories  reported  values  below  detection  limits. 
Therefore, ERM-EB074 has been considered to contain less than the highest LOD reported 
by  participating  laboratories.  With  95  %  confidence,  the  Hg  and  W  mass  fraction  of  the 
material  is  below  0.1  mg/kg  and  0.25  mg/kg,  respectively.  The  highest  LOD  reported  by 
participating laboratories is, therefore, a conservative estimate of the indicative value. 

For  Zr,  the  fact  that  all  neutron  activation  results  are  clustered  on  the  high  side  of  the 
population  indicates  that  significant  method  differences  might  have  been  found  if  more 
datasets had been obtained. For this reason, only indicative values were assigned. 

34 

 
 
Indicative values may not be used as certified values. The uncertainty budgets were set up 
as for the certified values and are listed together with the assigned values in Table 15. 

Table 15: Indicative values and their uncertainties for ERM-EB074A, B and C 

Analyte 

Hg 

S 

Sn 

W 

Zr 

Indicative value 1) 
[mg/kg] 
< 0.1 2) 

uchar, rel 
[%] 

ubb, rel 
[%] 

UCRM, rel 
[%] 

UCRM 
[mg/kg] 3) 

3.3 

13.26 

5.69 

28.86 

1.5 
< 0.25 2) 

2.74 

12.24 

25.08 

1.0 

0.4 

8.8 

8.62 

3.38 

18.52 

1.7 

1) rounded value 
2) With a 95 % probability, the indicative value is below this level. 
3) Expanded (k = 2) and rounded uncertainty. 

7.3  Additional material information 

The  data  provided  in  this  section  should  be  regarded  as  informative  only  on  the  general 
composition of the material and cannot be, in any case, used as certified or indicative value. 

For  Al,  the  inhomogeneity  observed  between  unit  and  the  high  uncertainty  between 
laboratories lead to a high expanded uncertainty for Al mass fraction in ERM-EB074A, B and 
C. For these reasons, the Al mass fraction and its uncertainties were reported as additional 
material information. 

Two  laboratories  (L9  and  L11)  performed  hydrogen  analysis  by  fusion  followed  by  thermal 
conductivity detection on 2 units of ERM-EB074A, B and C. The results are given as a range 
between the lowest unit mean and the highest unit mean. 

For  O,  the  inhomogeneity  observed  between  unit  and  the  small  number  of  laboratories 
involved in the intercomparison (p: 3 and 5) lead to a high uncertainty for O mass fraction in 
ERM-EB074A, B and C. Two of the three laboratories had recently successfully participated 
in  the  characterisation  of  O  in  titanium  alloy  [18].  The  results  were  regarded  as  sufficiently 
trustworthy to be reported in the additional material information section. 

Table 16: Summary of the additional material information. The range given reflects the range 
of individual results.p: The number of laboratories 

Analyte 

Al 

H 

O 

Mass fraction  

[mg/kg] 

0.3-1.9 

0.7 - 2.5 

7-11 

p 

8 

2 

3 

Number of measurements 

Method 

120 individual analyses 

See Annex C 

18 independent analysis / laboratory 

IGF-conductivity 

48 individual results 

See Annex C 

35 

 
 
 
 
 
 
 
 
 
 
 
 
 
8  Metrological traceability and commutability 

8.1  Metrological traceability  

Identity 

Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, Mg, Mn, Ni, O, P, Pb, S, Sb, Se, Si, Sn, Te, Ti, 
W,  Zn,  Zr  are  clearly  defined  analytes.  The  participants  used  different  methods  for  the 
sample  preparation,  as  well  as  for  the  final  determination,  demonstrating  the  absence  of 
measurement bias. The measurand is therefore structurally defined and independent of the 
measurement method. 

Quantity value 

Only  validated  methods  were  used  for  the  determination  of  the  assigned  values.  Different 
calibrants/calibrants  of  (known  purity  and),  specified  traceability  of  their  assigned  values 
were  used,  and  all  relevant  input  parameters  were  calibrated.  The  individual  results  are 
therefore  traceable  to  the  SI,  as  also  confirmed  by  the  agreement  among  the  technically 
accepted datasets. As the assigned values are combinations of agreeing results individually 
traceable to the SI, the assigned quantity values themselves are traceable to the SI as well. 

For Hg and W, the absence of the analyte at the level of the indicative value stated in Section 
7.2 was reported using validated methods that report results traceable to SI, so the reported 
LOD are therefore traceable to SI.  

8.2  Commutability 

Many measurement procedures include one or more steps, which are selecting specific (or 
specific  groups  of)  analytes  from  the  sample  for  the  subsequent  steps  of  the  whole 
measurement  process.  Often  the  complete  identity  of  these  'intermediate  analytes'  is  not 
entirely  known  or  taken  into  account.  Therefore,  it  is  difficult  to  mimic  all  the  analytically 
relevant properties of real samples within a CRM. The degree of equivalence in the analytical 
behaviour  of  real  samples  and  a  CRM  with  respect  to  various  measurement  procedures 
(methods)  is  summarised  in  a  concept called  'commutability  of  a  reference  material'. There 
are various definitions expressing this concept. For instance, the CSLI Guideline C-53A [19] 
recommends the use of the following definition for the term commutability: 

"The  equivalence  of  the  mathematical  relationships  among  the  results  of  different 
measurement procedures for an RM and for representative samples of the type intended 
to be measured." 

The commutability of a CRM defines its fitness for use and, thus, is a crucial characteristic in 
case of the application of different measurement methods. When commutability of a CRM is 
not established in such cases, the results from routinely used methods cannot be legitimately 
compared with the certified value to determine whether a bias does not  exist in calibration, 
nor can the CRM be used as a calibrant.  

It  should  be  borne  in  mind  that  the  methods  used  in  the  characterisation  are  methods 
routinely  applied  for  measuring  trace  elements  in  electrolytic  copper.  The  agreement  of 
results from different methods demonstrates that the processing did not affect any properties 
relevant for these methods and that ERM-EB074A, B and C behave like a real sample. 

ERM-EB074A,  B  and  C  were  produced  from  pure  copper  with  added  impurities.  The 
analytical  behaviour  will  be  the  same  as  for  a  routine  sample  of  electrolytic  copper.  For 
samples other than electrolytic copper, the commutability has to be assessed. 

36 

 
 
 
 
9  Instructions for use 

9.1  Safety information 

The usual laboratory safety measures apply. 

9.2  Storage conditions 

The  materials  will  be  stored  at  18  °C  ±  5  °C  in  the  dark.  Please  note  that  the  European 
Commission  cannot  be  held  responsible  for  changes  that  happen  during  storage  of  the 
material at the customer's premises, especially of opened units/bottles. 

9.3  Preparation and use of the material 

For  ERM-EB074A  and  B,  the  usual  mechanical  cleaning  should  be  applied  prior  to  the 
measurement (the CRM and the user’s samples should be treated in the same way).  

For  ERM-EB074C,  it  is  recommended  to  clean  the  chips  chemically  before  use  to  remove 
any traces of oxidation. 

9.4  Minimum sample intake 

For ERM-EB074A, B and C, the minimum amount of sample to be used is 10 mg for Ag, Al, 
As, Be, Bi, Cd, Co, Cr, Fe, Mg, Mn, Ni, P, Pb, Sb, Se, Si, Ti and Zn; 20 mg for Au, In and Te. 

9.5  Use of the certified value 

The main purpose of these materials is to assess method performance, i.e. for checking the 
accuracy  of  analytical  results/calibration.  As  any  reference  material,  they  can  also  be  used 
for control charts or validation studies. 

Use as a calibrant 

It  is  not  recommended  to  use  this  matrix  material  as  calibrant.  If  used,  nevertheless,  the 
uncertainty  of  the  certified  value  will  be  taken  into  account  in  the  estimation  of  the 
measurement uncertainty. 

Comparing an analytical result with the certified value 

A result is unbiased if the combined standard uncertainty of measurement and certified value 
covers the difference between the certified value and the measurement result (see also ERM 
Application Note 1, www.erm-crm.org [20]).  

For  assessing  the  method  performance,  the  measured  values  of  the  CRMs  are  compared 
with the certified values. The procedure is described here in brief:  

-  Calculate  the  absolute  difference  between  mean  measured  value  and  the  certified 

value (D meas). 

-  Combine  measurement  uncertainty 

(umeas)  with 

the  uncertainty  of 

the  

certified value (uCRM): 

u

=D

u

2
meas

+

u

2
CRM

-  Calculate the expanded uncertainty (UD ) from the combined uncertainty (uD

,) using an 
appropriate coverage factor, corresponding to a level of confidence of approximately 
95 % 
If  D meas  £   UD   no  significant  difference  between  the  measurement  result  and  the 
certified value, at a confidence level of about 95 % exists. 

- 

37 

 
 
 
 
 
Use of quality control charts 

The materials can be used for quality control charts. Different CRM-units will give the same 
result as inhomogeneity was included in the uncertainties of the certified values. 

10  Acknowledgments 

The authors would like to acknowledge the support received from members of the processing 
team from IRMM for the support in the processing of this CRM. 

Furthermore,  the  authors  would  like  to  thank  Liesbet  Deprez  and  Jenny  Chung  (IRMM)  for 
the  reviewing  of  the  certification  report,  as  well  as  the  experts  of  the  Certification  Advisory 
Panel "CAP Element", Steve Balsley (IAEA, AT), Thomas Meisel (Montanuniversität Leoben, 
AT) and Peter Vermaercke (SCK-CEN, BE) for their constructive comments. 

38 

 
 
11 References 

1  

2  

3  

4  

5  

ISO  Guide  34,  General  requirements  for  the  competence  of  reference  materials 
producers, International Organization for Standardization, Geneva, Switzerland, 2009 

ISO Guide 35, Reference materials – General and statistical principles for certification, 
International Organization for Standardization, Geneva, Switzerland, 2006 

ISO/IEC  17025:2005,  General  requirements  for  the  competence  of  testing  and 
calibration 
for  Standardization,  Geneva, 
Switzerland, 2005 

International  Organization 

laboratories, 

ISO/IEC  Guide  98-3,  Guide  to  the  Expression  of  Uncertainty  in  Measurement,  (GUM 
1995), International Organization for Standardization, Geneva, Switzerland, 2008 

International Copper Study Group. The World Copper Factbook 2013. Lisbon, Portugal: 
International Copper Study Group, 2013 

6   M. Radetzki, Seven thousand years in the service of humanity—the history of copper, 

the red metal, Resources Policy 34 (2009) 176-184 

7  

8  

9  

G. Joseph, Copper: Its Trade, Manufacture, Use, and Environmental Status, G. Joseph 
K. Konrad (Eds), ASM International, Materials Park, USA, 1999 
U.  Bogdanović,  V.  Lazić,  V.  Vodnik,  M.  Budimir,  Z.  Marković,  S.  Dimitrijević,  Copper 
nanoparticles with high antimicrobial activity, Materials Letters 128 (2014) 75-78 

EN 1978:1998, Copper and copper alloys. Copper cathodes, European Committee for 
standardisation, Brussels, Belgium, 1998 

10   GB/T  467-2010,  Copper  cathode,  General  Administration  of  Quality  Supervision, 
Inspection and Quarantine of the People's Republic of China (AQSIQ), Beijing, China, 
2010 

11   ASTM Standard B115, 2010, "Standard Specification for Electrolytic Copper Cathode" 

ASTM International, West Conshohocken, PA, USA, 2010 

12   S.  Vandendriessche,  B.  Griepink,  K.  Strijckmans,  The  certification  of  impurities  (  Ag, 
As,  Bi,  Cd,  Co,  Cr,  Fe,  Mn,  Ni,  Pb,  Sb,  Se,  Sn,  Te  and  Zn)  in  copper,  CRM  074: 
Electrolytic  copper,  CRM  075:  copper  with  added  impurities.  Commission  of  the 
European Communities , Luxembourg, Luxembourg, 1992 

13   EN1981,  2003,  “Copper  and  copper  alloys  -  Master  alloys”,  European  Committee  for 

standardisation, Brussels, Belgium, 2003 

14   ASTM E826, 2008 " Standard Practice for Testing Homogeneity of a Metal Lot or Batch 
in  Solid  Form  by  Spark  Atomic  Emission  Spectrometry"  ASTM  International,  West 
Conshohocken, PA, 2008 

15   T.P.J.  Linsinger,  J.  Pauwels,  A.M.H.  van  der  Veen,  H.  Schimmel,  A.  Lamberty, 

Homogeneity and stability of reference materials, Accred. Qual. Assur. 6 (2001) 20-25 

16   M Cox (2007) The evaluation of key comparison data: Determining the largest consistent 

subset, Metrologia 44:187–200 

17   A. Makashima, R. Tanaka, E. Nakamura (2009) Precise elemental and isotopic analyses 
in  silicate  samples  employing  ICP-MS:  Application  of  hydrofluoric  acid  solution  and 
analytical techniques, Analyt. Scie. 25:1181-1187 

18   T.  Bacquart,  T.  Linsinger,  The  certification  of  the  minor  elements  and  trace  elements 
mass  fraction  in  TiAl6V4:  BCR®-089.  EUR  Report  26831–  European  Community, 
Luxembourg – 2014 ISBN ???? 

39 

 
 
 
19  H.  Vesper,  H.  Emons,  M.  Gnezda,  C.  P.  Jain,  W.  G.  Miller,  R.  Rej,  G.  Schumann,  J. 
Tate,  L.  Thienpont,  J.  E.  Vaks,  Characterization  and  Qualification  of  Commutable 
Reference  Materials  for  Laboratory  Medicine;  Approved  Guideline,  CLSI  document 
EP30-A, Clinical and Laboratory Standards Institute, Wayne, PA, USA, 2010 

20  T.P.J.  Linsinger,  ERM  Application  Note  1:  Comparison  of  a  measurement  result  with 

the certified value, www.erm-crm.org (last accessed on 17/09/2014) 

40 

 
 
 
Annexes 

Annex A: Results of the between-unit homogeneity measurements 

Results  of  the  homogeneity  studies  for  the  three  formats  ERM-EB074A,  B  and  C.  The 
studies  were  not  performed  using  the  same  technique  (Table  2)  which  may  explain  the 
difference  in  results  between  the  three  formats.  The  unit  means  are  presented  after 
correction  for  analytical  trend  and  normalisation  to  the  mean  of  the  three  formats'  means. 
The  associated  uncertainty  equals  to  swb  from  ANOVA  for  all  units  of  each  study.  The 
distance between tick marks is 200 units. 

The  within-billet  homogeneity  study  was  performed  using  the  first  nine  units  of  ERM-
EB074A. 

Ag (Silver) 

41 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Al (Aluminium) 

As (Arsenic) 

42 

 
 
 
 
 
 
 
 
 
 
 
 
Au (Gold) 

Be (Beryllium) 

43 

 
 
 
 
 
 
 
 
 
 
 
Bi (Bismuth) 

Cd (Cadmium) 

44 

 
 
 
 
 
 
 
 
Co (Cobalt) 

Cr (Chromium) 

45 

 
 
 
 
 
 
 
 
 
Fe (Iron) 

In (Indium) 

46 

 
 
 
 
 
 
 
 
 
 
Mg (Magnesium) 

Mn (Manganese) 

47 

 
 
 
 
 
 
 
 
 
 
 
Ni (Nickel) 

O (Oxygen) 

48 

 
 
 
 
 
 
 
 
 
 
P (Phosphorus) 

Pb (Lead) 

49 

 
 
 
 
 
 
 
 
 
S (Sulfur) 

Sb (Antimony) 

50 

 
 
 
 
 
 
 
 
Se (Selenium) 

Si (Silicon) 

51 

 
 
 
 
 
 
 
 
 
Sn (Tin) 

Te (Tellurium) 

52 

 
 
 
 
 
 
 
 
 
 
 
Ti (Titanium) 

Zn (Zinc) 

53 

 
 
 
 
 
 
 
 
 
 
 
Zr (Zirconium) 

54 

 
 
 
 
 
Annex B: Results of the minimum sample intake measurements  

The results presented in the Table correspond to the mean of each area on the four different 
disc  faces  analysed  of  ERM-EB074A.  The  standard  deviation  reported  is  the  standard 
deviation between the results of the four disc faces. The measurements were performed by 
spark-OES except for Au, In and Te which were tested by GD-MS. 

Central area 

Intermediate area 

External area 

Corrected / 
Normalised 
results 
[mg/kg] 
1.023 

Standard 
deviation of the 
measurements 
[mg/kg] 
0.030 

Corrected / 
Normalised 
results 
[mg/kg] 
1.064 

Standard 
deviation of the 
measurements 
[mg/kg] 
0.020 

Corrected / 
Normalised 
results 
[mg/kg] 
1.068 

Standard 
deviation of the 
measurements 
[mg/kg] 
0.009 

1.447 

1.457 

0.946 

0.603 

0.382 

0.563 

0.426 

0.986 

5.657 

0.825 

2.073 

0.926 

0.562 

1.768 

2.777 

4.159 

1.438 

0.802 

1.717 

2.280 

0.857 

1.351 

2.241 

6.104 

0.050 

0.100 

0.021 

0.006 

0.072 

0.025 

0.055 

0.073 

0.119 

0.069 

0.043 

0.054 

0.073 

0.150 

0.162 

0.261 

0.220 

0.096 

0.180 

0.363 

0.070 

0.018 

0.079 

0.096 

1.458 

1.588 

n.a. 

0.627 

0.358 

0.558 

0.461 

0.937 

5.426 

n.a. 

2.131 

0.930 

0.509 

1.781 

3.034 

4.155 

1.184 

0.795 

1.629 

2.192 

n.a. 

1.345 

2.164 

6.289 

0.072 

0.084 

n.a. 

0.006 

0.099 

0.024 

0.107 

0.073 

0.242 

n.a. 

0.019 

0.036 

0.031 

0.036 

0.260 

0.166 

0.248 

0.071 

0.092 

0.353 

n.a. 

0.013 

0.169 

0.146 

1.473 

1.559 

1.009 

0.625 

0.347 

0.527 

0.404 

0.920 

5.257 

1.029 

2.137 

0.934 

0.490 

1.841 

3.135 

4.315 

1.206 

0.771 

1.732 

2.310 

1.024 

1.347 

2.230 

6.507 

0.044 

0.118 

0.011 

0.009 

0.076 

0.021 

0.087 

0.035 

0.173 

0.025 

0.010 

0.039 

0.031 

0.073 

0.111 

0.117 

0.197 

0.035 

0.047 

0.313 

0.030 

0.010 

0.077 

0.085 

Analyte 

Ag 

Al 

As 

Au 1) 

Be 

Bi 

Cd 

Co 

Cr 

Fe 

In 1) 

Mg 

Mn 

Ni 

P 

Pb 

S 

Sb 

Se 

Si 

Sn 

Te 1) 

Ti 

Zn 

Zr 

1) element analysed by GD-MS, the analysis area did not allow to perform measurements in 
the intermediate area. 

55 

 
 
  
 
 
Annex C: Summary of methods used in the characterisation study 

Laboratory code: L1 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Be, Bi, Cd, Co, Cr, In, Mg, 
Mn, Ni, Pb, Sn, Te, Ti, Zn, Zr 

ICP-MS 

1 

Hot acid digestion in 
HNO3  

Cu 

Titration 

0.5 - 1 

n.a. 

Fe, P, Sb 

ICP-OES 

Au and Se 

INAA 

Hg 

O, H 

S 

CV-AAS 

IGF-IR 

C-IR 

1 

1 

1 

1 

1 

Hot acid digestion in 
HNO3 

n.a. 

n.a. 

n.a. 

n.a. 

external calibration, prepared 
from certified standard 
solutions Inorganic Venture 
Pure Cu shot from Alfa Aesar 
external calibration, prepared 
from certified standard 
solutions Inorganic Venture 
external calibration, prepared 
from certified standard 
solutions Inorganic Venture 
external calibration, prepared 
from certified standard 
solutions ISOSpec 
RM from LECO and Alfa 
Aesar 
using metal RM from Alpha 

ELAN and Agilent 
7700x 

Metrohm 

Agilent 735-ES 

Canberra Ge 
Detector GC1318 

CETAC M-7600 

Eltra ONH-2000 

Leco CS-200 

Laboratory code: L2 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, In, 
Mg, Mn, Ni, P, Pb, Sb, Se, Sn, Te, Ti, 
Zn, Zr 
Cu 

ICP-OES 

electrogravimetry 

4 

2 

Hot acid digestion in 
HNO3 and HF 

Dissolution in HNO3 

external calibration, prepared 
from certified standard 
solutions 

Spectro (Arcos) and 
Perkin Elmer 
(5300DV) 

S 

spark-OES 

n.a. 

n.a. 

23 copper RMs and CRMs 
including BAM-M-381-386 
and BCR-074 and BCR-075 

Spectro Lab M9 

56 

 
 
 
 
 
 
 Laboratory code: L3 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

As, Bi, Ni, Pb, Sb, Se, Sn, Te 

ETV-ICP-OES 

0.02 

n.a. 

4 copper RMs and CRMs 
including BCR-074 and BCR-075 

Spectro Arcos-EOP 

Laboratory code: L4 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, In, 
Mg, Mn, Ni, P, Pb, S, Sb, Se, Sn, Te, 
Ti, W, Zn, Zr 

ICP-MS 

1 

Hot acid digestion in 
HNO3 and HF 

external calibration, prepared 
from certified standard 
solutions from Merck, Alfa 
Aesar and Bernd Kraft 

Thermo Element XR 

Laboratory code: L5 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, In, 
Mg, Mn, Ni, P, Pb, S, Sb, Se, Si, Sn, 
Te, Ti, W, Zn, Zr 

GD-MS 

n.a. 

n.a. 

Solid calibrants prepared from 
certified standard solutions 
from Merck, Alfa Aesar and 
Bernd Kraft 

Thermo Element GD 

Laboratory code: L6 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

As, Be, Bi, Fe, Pb, Sb, Se, Sn, Te 

ICP-MS 

Ag, Cd, Co, Cr, Mn, Ni, P, Si, Zn 

ICP-OES 

2.5 

2.5 

Acid digestion/Yttrium 
collection to remove 
Cu matrix 

Acid digestion 

High Purity certified stds 

Perkin-Elmer Elan 
DRCII 

SCP PlasmaCal certified stds 

Varian 735-ES 

57 

 
 
 
 
 
 
Laboratory code: L7 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, As, Bi, Fe, Ni, Pb, S, Sb, Se, 
Sn, Te, Zn 

DC-arc-OES 

0.3 

n.a. 

NIST and Leco for sulfur  

Copper Spec for all others 

Teledyne Leeman 
Prodigy  

Laboratory code: L8 

Elements 

Technique 

Sample mass 
[g] 

Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, Hg, 
In, Mg, Mn, Ni, P, Pb, Sb, Se, Sn, Te, 
Ti, W, Zn, Zr 

ICP-MS 

0.1 

Sample preparation 

Calibration 

Instrumentation  

Acid digestion with 
HNO3 

external calibration, prepared 
from certified standard solutions 
from Inorganic Venture 

Perkin Elmer DRC II 

Laboratory code: L9 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Be, Bi, Cd, Co, Cr, Fe, Hg, 
In, Mg, Mn, Ni, P, Pb, Sb, Se, Sn, Te, 
Ti, W, Zn, Zr 

ICP-MS 

0.1 

Acid digestion with 
HNO3 

O 

H 

S 

IGF-IR 

IGF-conductivity 

C-IR 

1 

1 

1 

n.a. 

n.a. 

n.a. 

external calibration, prepared 
from certified standards solution 
from Inorganic Venture 
external calibration with RMs 
from Alpha Resources and LECO 
external calibration with RMs 
from Alpha Resources and LECO 
external calibration with RMs 
from Alpha Resources and LECO 

Perkin Elmer Elan 
9000 

LECO TC-436 

LECO TC-436 

Analyseur C/S 
Horiba EMIA 820V 

58 

 
 
 
 
 
 
Laboratory code: L10 

Elements 

Ag, As, Au, Co, Cr, Cu, Fe, Hg, In, Sb, 
Se, Te, Zn 

Technique 

k0 neutron 
activation 
analysis 

Laboratory code: L11 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

0.2 

n.a. 

IRMM-530R 

250 kW TRIGA Mark II reactor 
(GA), HPGe detector with 40 % 
relative efficiency (Canberra) 

Elements 

Technique 

Sample mass 
[g] 

Ag, Al, As, Be, Bi, Cd, Co, Cr, Hg, In, 
Mg, Mn, Ni, Pb, S, Sb, Se, Sn, Te, Ti, 
W, Zn, Zr 

ICP-MS 

Fe, Mn, P, Si 

ICP-OES 

Au 

ICP-MS 

O, S, H 

E1019 

0.1 

0.5 

0.1 

1 

Sample preparation 

Calibration 

Instrumentation  

Acid digestion with 
HNO3 

Acid digestion with 
HNO3 

Acid digestion with 
HNO3 and HCl 

n.a. 

external calibration, prepared 
from certified standard 
solutions from VHG 
external calibration, prepared 
from certified standard 
solutions from VHG 
external calibration, prepared 
from certified standard 
solutions from VHG 
external calibration with RM 
from Alpha Resources and 
LECO 

THERMO iCAP QC 

SPECTRO ARCOS 

THERMO iCAP QC 

LECO 

59 

 
 
 
 
 
 
 
 
Laboratory code: L12 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Bi, Cd, Co, In, Pb 

ICP-MS 

0.25 

Cr, Fe, Ni, P, Zn 

ICP-MS 

0.05 

Acid digestion with 
HNO3 

Acid digestion with 
HNO3 

external calibration, 
prepared from pure metal, 
KRISS CRM and from 
certified standard solutions 
from Perkin Elmer 
external calibration, 
prepared from pure metal, 
KRISS CRM and from 
certified standard solutions 
from Perkin Elmer 

Perkin-Elmer NEXION 
300 

Thermo Fisher  
ELEMENT XR 
magnetic sector field 
ICP mass spectrometer 

Laboratory code: L13 

Elements 

Technique 

Sample mass 
[g] 

Sample 
preparation 

Ag, Al, As, Bi, Cd, Co, Cr, Fe, Mg, Mn, 
Ni, O, P, Pb, S, Sb, Se, Sn, Te, Ti, Zn 

GD-MS 

n.a. 

n.a. 

Calibration 

Instrumentation  

external calibration using certified 
reference materials (BCR-075, BCR-022, 
SRM-494, BAM M382 and BAM M386) 

VG9000 

Laboratory code: L14 

Elements 

Technique 

Sample mass 
[g] 

Sample 
preparation 

Calibration 

Instrumentation  

Ag, As, Au, Co, Cr, Cu, Fe, In, Sb, Se, 
Te, Zn, Zr 

k0 neutron activation 
analysis 

0.2 

n.a. 

IRMM-530R 

Samples irradiated in 
reactor and measured with 
HPGe detectors 

60 

 
 
 
 
 
Laboratory code: L15 

Elements 

Technique 

Sample mass 
[g] 

Sample 
preparation 

Ag, Au, Co, Cr, Fe, Sb, Se, Zn, Zr 

Instrumental neutron 
activation analysis 

0.2 

n.a. 

Calibration 

Instrumentation  

Calibration using SRMs 
from NIST 

Samples irradiated in 
nuclear reactor  
Detector: 2 HPGe coaxial 

Laboratory code: L16 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

As, Au, Bi, Cd, Cr, Hg, In, Ni, P, Pb, S, 
Sb, Se, Sn, Te, Ti, W, Zn 

ICP - MS 

Ag, Al, Be, Co, Fe, Mg, Mn, Si, Zr 

ICP-OES 

2 

2 

Digestion with HCl 
and HNO3 
Digestion with HCl 
and HNO3 

external calibration, prepared from 
certified standard solutions from Merck 
external calibration, prepared from 
certified standard solutions from Merck 

Thermo iCAP Q 

Varian 725ES 

Laboratory code: L17 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

As, Au, Be, Bi, Cd, Co, Cr, Fe, Hg, In, 
Mg, Mn, Ni, Pb, Sb, Se, Sn, Te, Ti, W, 
Zn, Zr 

ICP - MS 

2 

Digestion with HCl 
and HNO3 

Ag 

ICP - MS 

0.5 

Digestion with HNO3 

Al, P, S, Si 

ICP-OES 

O 

C-IR 

5 

1 

61 

Digestion with HCl 
and HNO3 

external calibration, prepared 
from certified standard solutions 
from Merck 
external calibration, prepared 
from certified standard solutions 
from Merck 
external calibration, prepared 
from certified standard solutions 
from Merck and Alfa Aesar 

Agilent 7500cx 

Agilent 7500cx 

Varian 730-ES  

n.a. 

LECO RM 

Leco TC600 

 
 
 
 
 
 
Laboratory code: L18 

Elements 

Technique 

Sample mass 
[g] 

Sample preparation 

Calibration 

Instrumentation  

Ag, Al, As, Au, Be, Bi, Cd, Co, Cr, Fe, 
Hg, In, Mg, Mn, Ni, Pb, Sb, Se, Sn, Te, 
Ti, W, Zn, Zr 

ICP-MS 

0.2 

Hot acid digestion 
with HNO3 

external calibration, prepared 
from certified standard 
solutions from Inorganic 
Ventures 

Agilent technologies 
AT 7500 CCT 

Laboratory code: L20 

Elements 

Technique 

Sample mass 
[g] 

As, Au, Be, Bi, Cd, Co, Cr, Fe, In, Mg, 
Mn, Ni, Pb, Se, Te, Ti, Zr, W 

ICP-MS 

0.25 g 

Ag, Al, Sb, Sn, Zn 

ICP-MS 

0.25 g 

Sample preparation 

Calibration 

Instrumentation  

Dissolution in closed 
vessel with acid 
and HBF4 

Open vessel 
dissolution with acid 

external calibration, prepared 
from certified standard 
solutions for ICP 
external calibration, prepared 
from certified standard 
solutions for ICP 

Agilent ICP-MS 
7700 

Agilent ICP-MS 
7700 

Laboratory code: L21 

Elements 

Technique 

Sample mass 
[g] 

Ag, As, Bi, Cd, Co, Cr, Fe, Mn, Ni, P, 
Pb, S, Sb, Se, Sn, Te, Zn 

Spark-OES 

n.a. 

Sample preparation 

Calibration 

Instrumentation  

Sample cleaned with 
diluted HNO3 and 
ethanol 

external calibration using 
CRMs 

Spectrolab M8 

62 

 
 
 
 
 
 
 
 
Annex D: Results of the characterisation measurements for ERM-EB074A, B and C (data not pooled). 

The results reported correspond to the mean of the mean of the laboratory for each format (ERM-EB074A, B and C). 

ERM-EB074A 

ERM-EB074B 

ERM-EB074C 

Mean of laboratory 
mean 
[mg/kg] 
1.007 
0.741 
1.209 
0.499 
0.294 
0.478 
0.402 
0.807 
0.372 
6.065 
0.482 
2.018 
0.924 
0.612 
7.497 
1.522 
2.670 
3.178 
0.572 
0.551 
1.235 
1.455 
0.529 
0.970 
2.201 
6.175 

Analyte 
Ag 
Al 
As 
Au 
Be 
Bi 
Cd 
Co 
Cr 
Fe 
In 
Mg 
Mn 
Ni 
O 
P 
Pb 
S 
Sb 
Se 
Si 
Sn 
Te 
Ti 
Zn 
Zr 

standard deviation 
of mean 
[mg/kg] 
0.022 
0.142 
0.030 
0.026 
0.021 
0.034 
0.018 
0.040 
0.014 
0.457 
0.015 
0.140 
0.025 
0.023 
1.001 
0.091 
0.074 
0.359 
0.020 
0.039 
0.185 
0.051 
0.027 
0.061 
0.132 
1.429 

Mean of 
laboratory mean 
[mg/kg] 
1.041 
0.755 
1.230 
0.500 
0.291 
0.475 
0.395 
0.794 
0.378 
5.640 
0.490 
2.056 
0.894 
0.604 
8.942 
1.597 
2.668 
3.449 
0.565 
0.551 
1.289 
1.520 
0.519 
0.915 
2.158 
6.002 

63 

standard deviation 
of mean 
[mg/kg] 
0.033 
0.164 
0.034 
0.028 
0.025 
0.033 
0.020 
0.040 
0.020 
0.169 
0.015 
0.130 
0.031 
0.014 
0.826 
0.107 
0.084 
0.713 
0.019 
0.025 
0.200 
0.068 
0.022 
0.063 
0.122 
1.320 

Mean of 
laboratory mean 
[mg/kg] 
1.032 
0.747 
1.262 
0.530 
0.310 
0.486 
0.410 
0.782 
0.370 
5.644 
0.502 
2.040 
0.928 
0.608 
8.206 
1.566 
2.398 
3.187 
0.566 
0.550 
1.356 
1.522 
0.525 
0.975 
2.243 
6.215 

standard deviation 
of mean 
[mg/kg] 
0.023 
0.172 
0.042 
0.026 
0.027 
0.023 
0.018 
0.040 
0.015 
0.238 
0.017 
0.130 
0.024 
0.013 
1.294 
0.127 
0.286 
0.622 
0.018 
0.063 
0.070 
0.028 
0.044 
0.072 
0.121 
1.324 

 
 
  
Annex E: Results of the characterisation measurements 

The characterisation study was performed using the results with the number of significant digits provided by each laboratory. In the Figures of 
Annex E, the results are reported with two significant digits after the coma for formatting reason.  

Ag (Silver) 

Table E1. Individual results for Ag mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10 

Rep 11 

Rep 12 

Rep 13 

Rep 14 

Rep 15 

Rep 16 

Rep 17 

Rep 18 

Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

Lab code - 
Method 

L2-ICP-OES 

L4-ICP-MS 

L5-GD-MS 

L7-DC-arc-OES 

L8-ICP-MS 

L9-ICP-MS 

L10-INAA 

L11-ICP-MS 

L13-GD-MS 

L14-INAA 

L15-INAA 

L16-ICP-OES 

L17-ICP-MS 

L18-ICP-MS 

L20-ICP-MS 

1.00 

0.99 

0.96 

0.95 

1.30 

1.08 

0.93 

1.00 

0.99 

1.06 

0.86 

0.99 

0.85 

Results not used for certification 

L1-ICP-MS 

L12-ICP-MS 

L6-ICP-OES 

L21-Spark-OES 

0.34 

0.92 

< 1 

< 2 

1.00 

1.15 

0.97 

0.95 

0.99 

1.12 

0.91 

1.06 

1.03 

1.10 

0.93 

1.02 

0.88 

0.26 

0.84 

< 1 

< 2 

1.00 

1.12 

0.91 

0.96 

1.25 

1.10 

0.97 

1.05 

0.94 

1.00 

0.90 

1.03 

0.87 

0.23 

0.83 

< 1 

< 2 

1.00 

1.00 

1.05 

0.94 

1.19 

1.09 

0.92 

1.01 

1.03 

1.19 

0.89 

1.06 

0.87 

0.35 

0.93 

< 1 

< 2 

1.20 

1.15 

0.91 

0.96 

0.99 

1.12 

0.91 

1.08 

1.01 

1.17 

0.89 

1.01 

0.92 

0.19 

0.86 

< 1 

< 2 

1.00 

1.00 

0.93 

0.97 

0.98 

1.12 

0.90 

1.03 

1.04 

1.02 

0.95 

1.05 

0.87 

0.29 

0.98 

< 1 

< 2 

1.00 

1.16 

1.05 

0.97 

1.25 

1.12 

0.92 

1.11 

0.99 

1.05 

0.93 

1.00 

1.23 

0.14 

0.84 

< 1 

< 2 

1.00 

1.02 

0.99 

0.96 

1.31 

1.10 

0.94 

1.03 

1.03 

1.09 

0.67 

1.04 

1.26 

0.18 

0.95 

< 1 

< 2 

1.00 

1.14 

0.96 

0.95 

0.99 

1.11 

1.03 

1.08 

1.01 

1.05 

0.67 

1.04 

1.09 

0.26 

0.84 

< 1 

< 2 

1.00 

1.03 

0.93 

0.96 

1.27 

1.10 

1.04 

1.03 

1.04 

1.15 

0.71 

1.05 

1.23 

0.38 

0.98 

< 1 

< 2 

1.00 

1.03 

0.89 

0.95 

1.27 

1.11 

0.90 

1.07 

0.94 

1.14 

0.86 

1.04 

1.30 

0.23 

0.94 

< 1 

< 2 

1.00 

1.18 

1.03 

0.95 

1.29 

1.12 

0.92 

1.08 

1.03 

1.08 

0.87 

1.06 

1.25 

0.23 

0.84 

< 1 

< 2 

64 

1.10 

1.03 

1 

0.95 

1.24 

1.10 

1.00 

1.02 

1.16 

0.92 

1.05 

0.87 

1.10 

0.22 

0.92 

< 1 

1.50 

1.03 

1 

0.97 

1.03 

1.16 

0.95 

1.06 

1.10 

0.98 

1.07 

0.90 

1.00 

0.28 

0.94 

< 1 

1.00 

1.18 

1 

0.96 

0.99 

1.13 

0.95 

1.09 

1.17 

0.76 

1.02 

0.90 

1.10 

0.17 

0.84 

< 1 

1.00 

1.19 

1 

0.95 

1.00 

1.17 

0.93 

1.10 

1.19 

1.32 

1.06 

0.90 

1.30 

0.27 

0.87 

< 1 

1.00 

1.04 

1 

0.96 

0.99 

1.12 

0.94 

1.04 

1.27 

0.77 

1.06 

0.95 

1.00 

0.24 

0.93 

< 1 

1.00 

0.72 

1 

0.97 

0.99 

1.14 

0.93 

1.09 

1.25 

0.78 

1.07 

0.90 

0.90 

0.23 

0.92 

< 1 

1.04 

1.06 

0.97 

1 

0.96 

1.13 

1.12 

0.94 

1.05 

1.03 

1.12 

0.87 

1.04 

1.00 

1.07 

0.25 

0.90 

0.25 

0.09 

0.10 

n.a. 

0.10 

0.23 

0.05 

0.24 

0.05 

0.05 

0.05 

0.14 

0.14 

0.34 

0.27 

0.13 

0.20 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E1.  Mean  Ag  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

65 

 
 
 
 
 
Al (Aluminium) 

Table E2. Individual results for Al mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L2-ICP-OES 

1.20 

1.20 

1.50 

1.30 

1.60 

1.20 

1.20 

1.30 

1.40 

1.30 

1.90 

1.30 

1.20 

1.30 

1.30 

1.40 

1.40 

1.20 

L5-GD-MS 

0.55 

0.36 

0.39 

0.71 

0.62 

0.37 

0.93 

0.96 

0.32 

0.95 

0.54 

0.40 

L8-ICP-MS 

0.45 

0.45 

0.45 

0.46 

0.46 

0.45 

0.45 

0.46 

0.46 

0.44 

0.45 

0.45 

0.47 

0.44 

0.46 

0.46 

0.47 

0.45 

L11-ICP-MS 

1.33 

1.26 

1.35 

1.40 

1.42 

1.12 

1.41 

1.21 

1.42 

1.39 

1.42 

1.46 

1.45 

1.31 

1.41 

1.41 

1.34 

1.38 

L13-GD-MS 

0.98 

1.00 

1.05 

1.07 

0.91 

0.98 

1.10 

1.02 

1.13 

1.05 

1.05 

1.14 

L16-ICP-MS 

0.65 

0.51 

0.27 

0.73 

0.51 

0.79 

0.30 

0.30 

0.38 

0.50 

0.49 

0.44 

0.44 

0.40 

0.33 

0.33 

0.61 

0.53 

L17-ICP-OES 

0.67 

0.55 

0.49 

0.61 

0.63 

0.56 

0.52 

0.50 

0.51 

0.56 

0.48 

0.51 

0.44 

0.55 

0.51 

0.61 

0.57 

0.56 

L20-ICP-MS 

Results not used for certification 

1.00 

1.00 

1.10 

0.90 

0.90 

1.10 

L1-ICP-MS 

1.41 

4.70 

2.88 

3.60 

1.80 

2.50 

5.30 

1.01 

1.34 

1.86 

2.19 

1.85 

2.18 

2.93 

3.32 

2.70 

1.91 

3.96 

L4-ICP-MS 

0.78 

0.99 

1.11 

0.51 

1.95 

0.21 

2.16 

1.45 

0.35 

3.08 

0.93 

0.43 

0.40 

1.43 

1.34 

1.66 

0.37 

1.25 

L9-ICP-MS 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

<1 

<1 

<1 

1.34 

0.59 

0.45 

1.36 

1.04 

0.47 

0.55 

1.00 

2.64 

1.13 

0.36 

0.43 

0.05 

0.34 

0.12 

0.16 

0.11 

0.18 

2.35 

0.17 

L18-ICP-MS 

14.26 

5.82 

17.11 

14.77 

13.41 

12.80 

11.74 

13.13 

20.56 

15.59 

10.80 

10.79 

12.64 

14.91 

15.41 

16.28 

15.33 

11.95 

13.74 

6.24 

66 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure E2. Mean Al mass fraction in ERM-EB074 reported by particpating laboratories. Error bars represent expanded uncertainties. The solid line represents 
the mean of laboratory means, while the broken lines represent the expanded uncertainty of the mean of laboratory means. Each laboratory is represented by 
its code. 

67 

 
 
 
As (Arsenic) 

Table E3. Individual results for As mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

1.30 

1.38 

1.09 

1.31 

1.20 

1.07 

1.28 

0.89 

1.29 

1.49 

1.18 

1.18 

1.36 

1.19 

1.15 

1.39 

1.25 

1.37 

L2-ICP-OES 

1.20 

1.10 

1.40 

1.10 

1.10 

1.10 

1.10 

1.10 

1.00 

1.20 

1.00 

1.30 

1.30 

1.00 

1.20 

1.10 

1.10 

1.20 

1.24 

1.14 

L3-ETV-ICP-OES 

1.17 

1.16 

1.14 

1.14 

1.16 

1.10 

1.10 

1.10 

1.15 

1.11 

1.15 

1.15 

1.16 

1.15 

1.16 

1.15 

1.13 

1.12 

1.13 

1.11 

1.14 

L4-ICP-MS 

1.08 

1.09 

1.14 

1.05 

1.05 

1.03 

1.15 

1.05 

1.05 

1.10 

1.09 

1.05 

1.08 

1.03 

1.11 

1.08 

1.05 

1.16 

L5-GD-MS 

1.13 

1.13 

1.01 

1.13 

1.01 

1.07 

1.15 

1.07 

1.06 

1.12 

1.04 

1.12 

L6-ICP-MS 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.30 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

1.20 

L7-DC-arc-OES 

1.20 

1.10 

1.00 

1.10 

1.10 

1.00 

L9-ICP-MS 

1.30 

1.22 

1.32 

1.27 

1.27 

1.25 

1.30 

1.25 

1.30 

1.31 

1.26 

1.28 

1.35 

1.26 

1.24 

1.24 

1.25 

1.25 

L10-INAA 

1.28 

1.09 

1.20 

1.12 

1.20 

1.20 

1.41 

1.29 

1.44 

1.26 

1.18 

1.22 

1.16 

1.42 

1.19 

1.35 

1.43 

1.30 

L11-ICP-MS 

1.18 

1.18 

1.23 

1.24 

1.21 

1.22 

1.19 

1.18 

1.21 

1.19 

1.21 

1.23 

1.23 

1.14 

1.20 

1.19 

1.21 

1.19 

L13-GD-MS 

1.07 

1.18 

1.14 

1.17 

1.10 

1.17 

1.24 

1.11 

1.18 

1.20 

1.16 

1.19 

L14-INAA 

1.22 

1.20 

1.25 

1.21 

1.24 

1.13 

1.31 

1.20 

1.26 

1.18 

1.30 

1.20 

1.35 

1.12 

1.31 

1.24 

1.27 

1.29 

L16-ICP-MS 

1.29 

1.87 

1.59 

1.22 

1.43 

1.31 

1.76 

1.16 

1.33 

1.72 

1.69 

1.49 

1.40 

1.31 

1.67 

1.67 

1.35 

1.69 

L17-ICP-MS 

1.24 

1.31 

1.39 

1.26 

1.38 

1.25 

1.29 

1.30 

1.24 

1.37 

1.38 

1.25 

1.25 

1.26 

1.38 

1.47 

1.23 

1.49 

L20-ICP-MS 

Results not used for certification 

1.50 

1.58 

1.65 

1.60 

1.55 

1.60 

L8-ICP-MS 

0.42 

0.40 

0.34 

0.39 

0.41 

0.38 

0.41 

0.41 

0.38 

0.41 

0.39 

0.39 

0.36 

0.35 

0.38 

0.38 

0.39 

0.41 

L18-ICP-MS 

1.79 

1.82 

1.77 

1.71 

1.88 

1.71 

1.55 

1.46 

1.56 

1.27 

1.04 

1.28 

1.70 

1.79 

1.83 

1.74 

1.75 

1.68 

L21-Spark-OES 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

1.08 

1.09 

1.21 

1.08 

1.27 

1.26 

1.20 

1.16 

1.24 

1.50 

1.32 

1.58 

0.39 

1.63 

0.28 

0.22 

0.07 

0.07 

0.09 

0.05 

0.15 

0.25 

0.15 

0.30 

0.13 

0.18 

0.33 

0.28 

0.10 

0.04 

0.46 

68 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E3.  Mean  As  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

69 

 
 
 
Au (Gold) 

Table E4. Individual results for Au mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-INAA 

0.48 

0.44 

0.41 

0.45 

0.50 

0.43 

0.45 

0.48 

0.43 

0.44 

0.42 

0.40 

0.50 

0.50 

0.46 

0.53 

0.46 

0.47 

L8-ICP-MS 

0.66 

0.66 

0.64 

0.65 

0.61 

0.65 

0.70 

0.62 

0.65 

0.68 

0.63 

0.66 

0.67 

0.64 

0.67 

0.65 

0.67 

0.64 

L10-INAA 

0.52 

0.53 

0.51 

0.51 

0.52 

0.52 

0.52 

0.52 

0.51 

0.53 

0.52 

0.52 

0.52 

0.53 

0.52 

0.54 

0.52 

0.53 

L11-ICP-MS 

0.57 

0.57 

0.59 

0.59 

0.59 

0.58 

0.56 

0.57 

0.57 

0.58 

0.57 

0.56 

0.56 

0.58 

0.58 

0.58 

0.59 

0.59 

L14-INAA 

0.50 

0.50 

0.51 

0.50 

0.51 

0.50 

0.51 

0.49 

0.51 

0.49 

0.52 

0.50 

0.54 

0.51 

0.51 

0.51 

0.53 

0.52 

L15-INAA 

0.52 

0.49 

0.50 

0.52 

0.53 

0.51 

0.50 

0.53 

0.52 

0.50 

0.50 

0.51 

0.52 

0.53 

0.52 

0.53 

0.53 

0.53 

L16-ICP-MS 

0.44 

0.41 

0.41 

0.37 

0.43 

0.35 

0.40 

0.21 

0.31 

0.46 

0.37 

0.34 

0.36 

0.35 

0.40 

0.40 

0.38 

0.50 

L17-ICP-MS 

0.40 

0.45 

0.46 

0.42 

0.45 

0.39 

0.52 

0.44 

0.46 

0.51 

0.48 

0.45 

0.47 

0.48 

0.48 

0.47 

0.42 

0.46 

L18-ICP-MS 

0.42 

0.43 

0.43 

0.48 

0.49 

0.48 

0.52 

0.45 

0.49 

0.49 

0.43 

0.49 

0.43 

0.47 

0.48 

0.49 

0.51 

0.53 

L20-ICP-MS 

Results not used for certification 

0.67 

0.68 

0.63 

0.62 

0.67 

0.65 

0.46 

0.65 

0.52 

0.58 

0.51 

0.52 

0.38 

0.46 

0.47 

0.65 

0.07 

0.07 

0.02 

0.08 

0.02 

0.01 

0.22 

0.10 

0.07 

0.05 

L9-ICP-MS 

0.34 

0.40 

0.41 

0.26 

0.31 

0.39 

0.37 

0.33 

0.36 

0.31 

0.34 

0.39 

0.30 

0.29 

0.28 

0.27 

0.27 

0.34 

0.33 

0.07 

70 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E4.  Mean  Au  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

71 

 
 
 
Be (Beryllium) 

Table E5. Individual results for Be mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.31 

0.29 

0.34 

0.32 

0.34 

0.32 

0.29 

0.26 

0.33 

0.33 

0.29 

0.26 

0.27 

0.26 

0.29 

0.30 

0.32 

0.30 

L2-ICP-OES 

0.39 

0.37 

0.38 

0.37 

0.38 

0.36 

0.37 

0.39 

0.38 

0.38 

0.38 

0.39 

0.39 

0.38 

0.38 

0.39 

0.38 

0.39 

L4-ICP-MS 

0.31 

0.36 

0.36 

0.29 

0.35 

0.29 

0.36 

0.32 

0.33 

0.35 

0.34 

0.32 

0.30 

0.30 

0.31 

0.35 

0.31 

0.35 

L5-GD-MS 

0.47 

0.33 

0.22 

0.26 

0.28 

0.26 

0.37 

0.37 

0.50 

0.32 

0.33 

0.39 

L6-ICP-MS 

0.37 

0.32 

0.32 

0.38 

0.36 

0.41 

0.34 

0.40 

0.38 

0.33 

0.34 

0.41 

0.40 

0.34 

0.34 

0.34 

0.37 

0.34 

L8-ICP-MS 

0.19 

0.20 

0.19 

0.21 

0.21 

0.20 

0.20 

0.22 

0.21 

0.19 

0.19 

0.20 

0.21 

0.19 

0.19 

0.19 

0.20 

0.20 

L9-ICP-MS 

0.36 

0.26 

0.29 

0.35 

0.35 

0.26 

0.30 

0.25 

0.32 

0.24 

0.26 

0.27 

0.31 

0.36 

0.28 

0.33 

0.34 

0.34 

L11-ICP-MS 

0.40 

0.30 

0.33 

0.29 

0.32 

0.33 

0.32 

0.40 

0.40 

0.36 

0.34 

0.38 

0.35 

0.35 

0.30 

0.36 

0.38 

0.34 

L16-ICP-MS 

0.19 

0.15 

0.15 

0.12 

0.16 

0.14 

0.11 

0.08 

0.14 

0.15 

0.16 

0.11 

0.18 

0.15 

0.22 

0.22 

0.16 

0.17 

L17-ICP-MS 

0.22 

0.22 

0.28 

0.21 

0.23 

0.21 

0.23 

0.22 

0.20 

0.28 

0.22 

0.20 

0.20 

0.21 

0.22 

0.28 

0.22 

0.27 

L18-ICP-MS 

0.34 

0.31 

0.33 

0.33 

0.34 

0.30 

0.28 

0.26 

0.29 

0.23 

0.20 

0.24 

0.27 

0.27 

0.29 

0.28 

0.29 

0.27 

L20-ICP-MS 

0.50 

0.50 

0.40 

0.60 

0.40 

0.60 

L1-ICP-MS 

0.31 

0.29 

0.34 

0.32 

0.34 

0.32 

0.29 

0.26 

0.33 

0.33 

0.29 

0.26 

0.27 

0.26 

0.29 

0.30 

0.32 

0.30 

0.30 

0.38 

0.33 

0.34 

0.36 

0.20 

0.30 

0.35 

0.15 

0.23 

0.28 

0.50 

0.30 

0.06 

0.02 

0.04 

0.13 

0.06 

0.02 

0.06 

0.09 

0.11 

0.06 

0.08 

0.18 

0.06 

72 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E5.  Mean  Be  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

73 

 
 
 
 
 
Bi (bismuth) 

Table E6. Individual results for Bi mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.47 

0.45 

0.45 

0.49 

0.45 

0.50 

0.45 

0.35 

0.50 

0.49 

0.41 

0.51 

0.53 

0.54 

0.49 

0.45 

0.49 

0.45 

L6-ICP-MS 

0.52 

0.47 

0.48 

0.52 

0.48 

0.53 

0.49 

0.51 

0.51 

0.48 

0.47 

0.51 

0.51 

0.47 

0.46 

0.46 

0.52 

0.47 

L7-DC-arc-OES 

0.50 

0.48 

0.50 

0.49 

0.48 

0.47 

L8-ICP-MS 

0.59 

0.56 

0.59 

0.58 

0.58 

0.60 

0.59 

0.57 

0.57 

0.59 

0.60 

0.58 

0.58 

0.57 

0.57 

0.57 

0.58 

0.58 

L9-ICP-MS 

0.50 

0.54 

0.57 

0.47 

0.62 

0.57 

0.52 

0.53 

0.52 

0.52 

0.60 

0.50 

0.49 

0.48 

0.51 

0.48 

0.49 

0.50 

L11-ICP-MS 

0.57 

0.56 

0.56 

0.63 

0.56 

0.55 

0.54 

0.54 

0.55 

0.60 

0.55 

0.57 

0.58 

0.55 

0.56 

0.58 

0.55 

0.55 

L12-ICP-MS 

0.48 

0.50 

0.48 

0.50 

0.47 

0.50 

0.47 

0.47 

0.48 

0.48 

0.47 

0.49 

0.50 

0.48 

0.48 

0.47 

0.49 

0.53 

L13-GD-MS 

0.49 

0.57 

0.56 

0.53 

0.57 

0.55 

0.55 

0.53 

0.55 

0.55 

0.59 

0.50 

L16-ICP-MS 

0.21 

0.27 

0.24 

0.43 

0.35 

0.51 

0.17 

0.46 

0.44 

0.46 

0.40 

0.40 

0.23 

0.26 

0.47 

0.69 

0.59 

0.31 

L17-ICP-MS 

0.46 

0.50 

0.51 

0.50 

0.50 

0.50 

0.49 

0.48 

0.49 

0.52 

0.51 

0.48 

0.49 

0.49 

0.50 

0.52 

0.49 

0.52 

L20-ICP-MS 

Results not used for certification 

0.53 

0.55 

0.56 

0.57 

0.56 

0.54 

0.47 

0.49 

0.49 

0.58 

0.52 

0.56 

0.48 

0.55 

0.38 

0.50 

0.55 

L2-ICP-OES 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

L3-ETV-ICP-OES 

0.43 

0.42 

0.40 

0.41 

0.41 

0.40 

0.39 

0.40 

0.42 

0.40 

0.42 

0.42 

0.41 

0.42 

0.42 

0.42 

0.40 

0.40 

0.41 

0.41 

0.41 

L4-ICP-MS 

0.45 

0.45 

0.45 

0.44 

0.44 

0.44 

0.45 

0.44 

0.44 

0.45 

0.44 

0.44 

0.44 

0.44 

0.45 

0.45 

0.45 

0.45 

L5-GD-MS 

0.33 

0.41 

0.44 

0.52 

0.42 

0.42 

0.52 

0.48 

0.32 

0.56 

0.49 

0.42 

L18-ICP-MS 

L21-Spark-OES 

0.21 
< 1.5 

0.23 
< 1.5 

0.24 
< 1.5 

0.27 
< 1.5 

0.27 
< 1.5 

0.26 
< 1.5 

0.25 
< 1.5 

0.21 
< 1.5 

0.24 
< 1.5 

0.23 
< 1.5 

0.21 
< 1.5 

0.23 
< 1.5 

0.26 

0.28 

0.30 

0.29 

0.31 

0.31 

0.45 

0.44 

0.26 

0.09 

0.05 

0.02 

0.06 

0.10 

0.14 

0.04 

0.06 

0.21 

0.02 

0.03 

0.04 

0.01 

0.11 

0.07 

74 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
]
g
k
/
g
m

[
n
o
i
t
c
a
r
f

s
s
a
m

i

B

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

S
M
-
P
C
I
-
6
1
L

S
M
-
P
C
I
-
1
L

S
M
-
P
C
I
-
2
1
L

S
E
O
-
c
r
a
-
C
D

-
7
L

S
M
-
P
C
I
-
6
L

S
M
-
P
C
I
-
7
1
L

S
M
-
P
C
I
-
9
L

-

S
M
D
G
-
3
1
L

S
M
-
P
C
I
-
0
2
L

S
M
-
P
C
I
-
1
1
L

S
M
-
P
C
I
-
8
L

Laboratory code / Method

Figure E6. Mean Bi mass fraction in ERM-EB074 reported by particpating laboratories. Error bars represent expanded uncertainties. The solid line represents 
the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each  laboratory  is 
represented by its code. 

75 

 
 
 
 
 
 
 
 
 
Cd (Cadmium) 

Table E7. Individual results for Cd mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.39 

0.37 

0.38 

0.36 

0.39 

0.40 

0.35 

0.26 

0.38 

0.40 

0.34 

0.35 

0.40 

0.41 

0.37 

0.37 

0.42 

0.37 

L2-ICP-OES 

0.34 

0.31 

0.33 

0.31 

0.34 

0.28 

0.32 

0.34 

0.33 

0.32 

0.34 

0.33 

0.32 

0.31 

0.32 

0.34 

0.28 

0.34 

L4-ICP-MS 

0.40 

0.43 

0.41 

0.39 

0.41 

0.38 

0.41 

0.39 

0.40 

0.40 

0.42 

0.40 

0.40 

0.40 

0.42 

0.41 

0.40 

0.41 

L5-GD-MS 

0.34 

0.39 

0.39 

0.39 

0.34 

0.38 

0.42 

0.39 

0.34 

0.41 

0.41 

0.39 

L8-ICP-MS 

0.41 

0.43 

0.42 

0.40 

0.39 

0.38 

0.41 

0.40 

0.40 

0.41 

0.41 

0.41 

0.40 

0.42 

0.41 

0.39 

0.40 

0.42 

L9-ICP-MS 

0.39 

0.29 

0.28 

0.37 

0.38 

0.28 

0.26 

0.26 

0.26 

0.28 

0.26 

0.27 

0.38 

0.39 

0.30 

0.37 

0.37 

0.38 

L11-ICP-MS 

0.44 

0.42 

0.41 

0.41 

0.43 

0.41 

0.41 

0.41 

0.42 

0.42 

0.43 

0.43 

0.43 

0.41 

0.41 

0.41 

0.40 

0.41 

L12-ICP-MS 

0.48 

0.37 

0.38 

0.43 

0.35 

0.42 

0.36 

0.45 

0.44 

0.37 

0.35 

0.44 

0.45 

0.44 

0.37 

0.36 

0.45 

0.36 

L13-GD-MS 

0.36 

0.44 

0.42 

0.40 

0.44 

0.44 

0.41 

0.41 

0.42 

0.42 

0.40 

0.37 

L16-ICP-MS 

0.50 

0.64 

0.61 

0.45 

0.55 

0.48 

0.67 

0.39 

0.48 

0.58 

0.59 

0.51 

0.48 

0.51 

0.60 

0.60 

0.46 

0.64 

L17-ICP-MS 

0.41 

0.45 

0.44 

0.45 

0.42 

0.45 

0.43 

0.43 

0.44 

0.44 

0.44 

0.43 

0.43 

0.43 

0.44 

0.46 

0.44 

0.45 

L20-ICP-MS 

Results not used for certification 

0.42 

0.41 

0.37 

0.40 

0.43 

0.42 

0.37 

0.32 

0.40 

0.38 

0.41 

0.32 

0.42 

0.40 

0.41 

0.54 

0.44 

0.41 

0.07 

0.04 

0.02 

0.06 

0.04 

0.06 

0.10 

0.14 

0.06 

0.13 

0.05 

0.04 

L6-ICP-OES 

L21-Spark-OES 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

L18-ICP-MS 

0.37 

0.38 

0.39 

0.34 

0.37 

0.35 

0.34 

0.31 

0.34 

0.30 

0.26 

0.30 

0.37 

0.38 

0.38 

0.38 

0.39 

0.38 

0.35 

0.07 

76 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E7.  Mean  Cd  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

77 

 
 
 
Co (cobalt) 

Table E8. Individual results for Co mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.87 

0.86 

0.88 

0.80 

0.85 

0.84 

0.85 

0.62 

0.83 

0.79 

0.81 

0.79 

0.84 

0.89 

0.81 

0.88 

L2-ICP-OES 

1.00 

1.00 

1.30 

0.80 

0.80 

0.90 

1.10 

1.10 

1.10 

0.80 

1.00 

0.90 

0.70 

0.70 

0.80 

0.80 

0.70 

0.80 

L4-ICP-MS 

0.87 

0.86 

0.86 

0.85 

0.87 

0.85 

0.86 

0.84 

0.84 

0.84 

0.82 

0.82 

0.80 

0.99 

0.81 

0.82 

0.81 

0.82 

L5-GD-MS 

0.90 

0.88 

0.90 

0.90 

0.94 

0.84 

0.91 

0.87 

0.88 

0.91 

0.86 

0.91 

L8-ICP-MS 

0.86 

0.83 

0.82 

0.84 

0.83 

0.83 

0.81 

0.81 

0.85 

0.81 

0.82 

0.80 

0.81 

0.82 

0.81 

0.80 

0.83 

0.81 

L9-ICP-MS 

0.86 

0.71 

0.71 

0.82 

0.84 

0.72 

0.74 

0.70 

0.70 

0.87 

0.72 

0.71 

0.75 

0.87 

0.76 

0.80 

0.83 

0.82 

L11-ICP-MS 

0.72 

0.71 

0.73 

0.70 

0.69 

0.69 

0.73 

0.74 

0.71 

0.71 

0.74 

0.74 

0.71 

0.69 

0.74 

0.67 

0.70 

0.70 

L12-ICP-MS 

0.71 

0.80 

0.88 

0.65 

0.87 

0.67 

0.75 

0.68 

0.69 

0.78 

0.85 

0.66 

0.68 

0.68 

0.83 

0.86 

0.67 

0.88 

L13-GD-MS 

0.82 

0.81 

0.82 

0.81 

0.81 

0.83 

0.81 

0.82 

0.83 

0.83 

0.79 

0.82 

L14-INAA 

0.95 

0.98 

0.81 

0.95 

0.94 

0.97 

0.93 

0.88 

0.96 

0.89 

0.94 

0.94 

0.93 

0.98 

0.95 

0.99 

0.96 

0.99 

L16-ICP-MS 

0.90 

0.93 

0.91 

0.76 

0.82 

0.82 

0.97 

0.60 

0.81 

0.88 

0.90 

0.82 

0.87 

0.89 

0.88 

0.88 

0.77 

0.94 

L17-ICP-MS 

0.82 

0.84 

0.92 

0.80 

0.86 

0.82 

0.79 

0.85 

0.81 

0.87 

0.89 

0.82 

0.82 

0.81 

0.86 

0.96 

0.81 

0.97 

L20-ICP-MS 

Results not used for certification 

0.80 

0.80 

0.80 

0.80 

0.80 

0.80 

L10-INAA 

1.56 

1.60 

1.54 

1.55 

1.54 

1.55 

1.56 

1.56 

1.56 

1.57 

1.55 

1.57 

1.56 

1.59 

1.54 

1.60 

1.54 

1.58 

L15-INAA 

0.69 

0.62 

0.63 

0.61 

0.66 

0.59 

0.62 

0.65 

0.62 

0.57 

0.64 

0.62 

0.64 

0.69 

0.69 

0.65 

0.66 

0.65 

L18-ICP-MS 

0.88 

0.84 

0.81 

0.73 

0.79 

0.73 

0.71 

0.66 

0.69 

0.56 

0.50 

0.58 

0.73 

0.73 

0.73 

0.73 

0.72 

0.69 

L6-ICP-OES 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

L21-Spark-OES 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

0.83 

0.91 

0.85 

0.89 

0.82 

0.77 

0.71 

0.76 

0.82 

0.94 

0.85 

0.85 

0.80 

1.56 

0.64 

0.71 

0.13 

0.34 

0.02 

0.07 

0.08 

0.18 

0.25 

0.30 

0.07 

0.05 

0.17 

0.05 

0.00 

0.06 

0.03 

0.19 

78 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E8.  Mean  Co  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

79 

 
 
 
 
Cr (Chromium) 

Table E9. Individual results for Cr mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.37 

0.44 

0.37 

0.49 

0.35 

0.42 

0.42 

0.33 

0.39 

0.39 

0.32 

0.39 

0.45 

0.56 

0.53 

0.38 

0.42 

0.50 

L2-ICP-OES 

0.40 

0.40 

0.50 

0.40 

0.40 

0.30 

0.40 

0.30 

0.40 

0.40 

0.50 

0.40 

0.40 

0.30 

0.50 

0.40 

0.40 

0.40 

L4-ICP-MS 

0.34 

0.35 

0.33 

0.32 

0.34 

0.33 

0.37 

0.32 

0.50 

0.00 

0.40 

0.34 

0.33 

0.41 

0.44 

0.36 

0.31 

0.33 

L5-GD-MS 

0.44 

0.31 

0.35 

0.39 

0.44 

0.39 

0.40 

0.42 

0.43 

0.42 

0.36 

0.33 

L8-ICP-MS 

0.42 

0.41 

0.42 

0.42 

0.41 

0.40 

0.42 

0.43 

0.41 

0.39 

0.40 

0.42 

0.42 

0.42 

0.41 

0.39 

0.40 

0.39 

L9-ICP-MS 

0.23 

0.72 

0.32 

0.27 

0.46 

0.86 

0.25 

0.23 

0.24 

0.18 

0.73 

1.67 

0.26 

0.30 

0.58 

0.34 

0.35 

0.35 

L10-INAA 

0.35 

0.36 

0.39 

0.35 

0.34 

0.33 

0.38 

0.36 

0.34 

0.40 

0.40 

0.43 

0.34 

0.36 

0.39 

0.33 

0.35 

0.45 

L11-ICP-MS 

0.35 

0.38 

0.36 

0.35 

0.34 

0.40 

0.33 

0.34 

0.35 

0.34 

0.38 

0.36 

0.36 

0.39 

0.37 

0.35 

0.38 

0.36 

L12-ICP-MS 

0.35 

0.44 

0.37 

0.35 

0.37 

0.38 

0.35 

0.34 

0.38 

0.34 

0.41 

0.33 

0.32 

0.33 

0.34 

0.35 

0.33 

0.33 

L13-GD-MS 

0.30 

0.30 

0.30 

0.30 

0.32 

0.32 

0.30 

0.31 

0.30 

0.31 

0.30 

0.30 

L16-ICP-MS 

0.33 

0.33 

0.32 

0.31 

0.32 

0.35 

0.34 

0.24 

0.32 

0.31 

0.32 

0.32 

0.33 

0.34 

0.32 

0.32 

0.31 

0.34 

L17-ICP-MS 

0.31 

0.39 

0.33 

0.36 

0.42 

0.39 

0.38 

0.30 

0.30 

0.35 

0.37 

0.37 

0.33 

0.34 

0.40 

0.30 

0.33 

0.28 

Results not used for certification 

L14-INAA 

0.37 

0.34 

0.38 

0.33 

0.35 

0.37 

0.30 

0.37 

0.36 

0.38 

0.33 

0.34 

L15-INAA 

0.38 

0.33 

0.43 

0.42 

0.35 

0.84 

0.42 

0.90 

0.28 

0.68 

0.33 

0.52 

0.48 

0.43 

0.41 

0.36 

0.40 

0.41 

L18-ICP-MS 

0.39 

0.40 

0.42 

0.41 

0.40 

0.39 

0.40 

0.56 

0.38 

0.27 

0.25 

0.31 

L20-ICP-MS 

L21-Spark-OES 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

0.32 
< 1 

0.31 
< 1 

0.32 
< 1 

0.30 
< 1 

0.30 
< 1 

0.29 
< 1 

0.42 

0.40 

0.34 

0.39 

0.41 

0.46 

0.37 

0.36 

0.36 

0.30 

0.32 

0.35 

0.35 

0.46 

0.36 

0.14 

0.12 

0.09 

0.08 

0.04 

0.09 

0.06 

0.09 

0.05 

0.03 

0.03 

0.08 

0.06 

0.03 

0.15 

80 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure E9. Mean Cr mass fraction in ERM-EB074 reported by particpating laboratories. Error bars represent expanded uncertainties. The solid line represents 
the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each  laboratory  is 
represented by its code. 

81 

 
 
 
Fe (Iron) 

Table E10. Individual results for Fe mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L2-ICP-OES 

10.40 

6.40 

7.70 

11.30 

11.90 

7.80 

4.60 

5.20 

6.20 

4.60 

11.10 

7.10 

4.70 

4.40 

5.20 

4.80 

5.40 

4.50 

L5-GD-MS 

5.44 

5.77 

6.09 

5.61 

5.63 

5.55 

5.76 

5.59 

5.50 

5.71 

5.85 

5.76 

L6-ICP-MS 

6.40 

5.90 

6.00 

6.00 

5.90 

6.00 

5.70 

5.60 

6.00 

6.10 

5.50 

5.50 

5.50 

5.40 

5.30 

5.30 

5.70 

5.50 

L11-ICP-OES 

4.80 

5.30 

5.00 

4.90 

4.90 

4.90 

4.90 

4.90 

4.90 

4.80 

4.80 

4.80 

4.70 

4.90 

4.70 

5.10 

5.30 

5.00 

L12-ICP-MS 

6.40 

6.20 

7.30 

5.30 

5.40 

4.50 

5.70 

6.20 

5.10 

6.40 

6.40 

7.80 

6.40 

7.30 

5.20 

7.00 

7.50 

5.10 

L13-GD-MS 

5.08 

5.10 

5.29 

5.00 

5.15 

5.11 

5.21 

5.23 

5.26 

5.25 

5.23 

5.12 

L14-INAA 

5.39 

5.34 

5.73 

5.44 

5.93 

5.58 

5.35 

6.41 

5.59 

6.00 

5.28 

7.19 

L16-ICP-OES 

5.93 

5.94 

5.55 

5.49 

4.77 

5.95 

6.35 

5.09 

6.54 

6.41 

5.69 

6.58 

5.83 

6.14 

5.28 

5.28 

5.93 

5.47 

L17-ICP-MS 

4.82 

5.18 

5.45 

4.60 

5.22 

4.42 

4.95 

4.97 

4.67 

5.26 

5.29 

4.78 

4.77 

4.66 

5.23 

5.66 

4.59 

5.63 

L18-ICP-MS 

L20-ICP-MS 

Results not used for certification 

6.03 

5.41 

5.44 

5.24 

5.43 

5.02 

7.00 

7.00 

8.00 

6.00 

7.00 

7.00 

L1-ICP-OES 

5.88 

5.57 

5.71 

6.72 

5.39 

6.38 

5.74 

3.94 

6.66 

7.77 

6.04 

13.83 

14.51 

11.53 

16.62 

5.71 

6.13 

5.74 

L8-ICP-MS 

5.80 

5.30 

5.90 

5.70 

5.80 

5.50 

5.90 

5.60 

5.80 

5.80 

5.80 

5.70 

5.90 

5.50 

5.60 

5.90 

5.50 

5.40 

L7-DC-arc-OES 

8.00 

11.00 

15.00 

9.00 

9.00 

8.00 

L9-ICP-MS 

5.85 

4.07 

4.02 

6.90 

4.50 

6.32 

4.23 

3.54 

7.04 

12.00 

6.67 

4.55 

5.74 

5.41 

3.98 

6.59 

6.77 

8.89 

L10-INAA 

< 7 

< 4 

< 6 

< 6 

< 6 

< 6 

12.6 

< 6 

< 6 

10.0 

< 7 

< 4 

< 7 

< 8 

< 4 

< 8 

< 7 

< 8 

L15-INAA 

6.72 

ND 

15.60 

12.10 

5.51 

119 

29.20 

143 

4.66 

98.30 

ND 

37.90 

6.84 

5.09 

6.22 

4.06 

5.81 

7.56 

L21-Spark-OES 

4.40 

4.40 

4.60 

4.30 

4.30 

4.30 

4.20 

4.70 

4.70 

4.60 

5.00 

4.60 

6.85 

5.69 

5.74 

4.92 

6.18 

5.17 

5.77 

5.79 

5.01 

5.43 

7.00 

7.77 

5.69 

10.00 

5.23 

0.70 

0.62 

1.23 

1.30 

0.23 

2.40 

0.81 

0.79 

1.99 

1.26 

7.36 

0.57 

5.37 

31.72 

4.51 

2.00 

0.46 

82 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E10.  Mean  Fe  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

83 

 
 
 
In (Indium) 

Table E11. Individual results for In mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.50 

0.50 

0.50 

0.49 

0.49 

0.50 

0.49 

0.36 

0.50 

0.53 

0.44 

0.48 

0.49 

0.50 

0.50 

0.50 

0.51 

0.49 

L2-ICP-OES 

0.40 

0.50 

0.40 

0.30 

0.50 

0.40 

0.50 

0.50 

0.50 

0.50 

0.50 

0.40 

0.50 

0.50 

0.50 

0.50 

0.40 

0.50 

L4-ICP-MS 

0.47 

0.50 

0.49 

0.46 

0.49 

0.46 

0.51 

0.46 

0.46 

0.51 

0.50 

0.46 

0.46 

0.46 

0.49 

0.50 

0.47 

0.49 

L5-GD-MS 

0.29 

0.39 

0.48 

0.53 

0.40 

0.46 

0.54 

0.53 

0.28 

0.61 

0.56 

0.40 

L8-ICP-MS 

0.52 

0.52 

0.50 

0.56 

0.53 

0.55 

0.50 

0.51 

0.54 

0.56 

0.56 

0.56 

0.54 

0.53 

0.53 

0.58 

0.57 

0.59 

L9-ICP-MS 

0.31 

0.52 

0.52 

0.31 

0.32 

0.53 

0.50 

0.52 

0.52 

0.30 

0.53 

0.53 

0.35 

0.34 

0.50 

0.34 

0.34 

0.34 

L10-INAA 

0.55 

0.55 

0.56 

0.50 

0.52 

0.54 

0.59 

0.51 

0.51 

0.61 

0.51 

0.50 

0.57 

0.53 

0.54 

0.53 

0.56 

0.57 

L11-ICP-MS 

0.52 

0.52 

0.52 

0.53 

0.53 

0.53 

0.53 

0.52 

0.53 

0.52 

0.53 

0.52 

0.55 

0.52 

0.53 

0.55 

0.52 

0.53 

L12-ICP-MS 

0.45 

0.39 

0.40 

0.46 

0.42 

0.45 

0.39 

0.45 

0.45 

0.40 

0.41 

0.45 

0.46 

0.46 

0.40 

0.43 

0.46 

0.44 

L14-INAA 

0.51 

0.47 

0.40 

0.54 

0.54 

0.51 

0.49 

0.45 

0.48 

0.43 

0.52 

0.54 

0.48 

0.46 

0.51 

0.50 

0.53 

0.46 

L16-ICP-MS 

0.52 

0.66 

0.65 

0.45 

0.58 

0.50 

0.75 

0.36 

0.48 

0.61 

0.61 

0.49 

0.50 

0.53 

0.60 

0.60 

0.45 

0.66 

L17-ICP-MS 

0.49 

0.56 

0.56 

0.54 

0.55 

0.56 

0.53 

0.52 

0.53 

0.58 

0.58 

0.54 

0.55 

0.53 

0.55 

0.58 

0.55 

0.58 

L18-ICP-MS 

0.39 

0.42 

0.42 

0.41 

0.44 

0.41 

0.41 

0.37 

0.40 

0.34 

0.30 

0.35 

0.42 

0.44 

0.45 

0.44 

0.45 

0.45 

L20-ICP-MS 

0.50 

0.60 

0.60 

0.60 

0.60 

0.50 

0.49 

0.46 

0.48 

0.46 

0.54 

0.42 

0.54 

0.53 

0.43 

0.49 

0.56 

0.55 

0.41 

0.57 

0.07 

0.12 

0.03 

0.17 

0.05 

0.08 

0.06 

0.13 

0.09 

0.07 

0.26 

0.07 

0.08 

0.10 

84 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E11.  Mean  In  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

85 

 
 
 
Mg (Magnesium) 

Table E12. Individual results for Mg mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L2-ICP-OES 

2.10 

1.80 

1.90 

1.80 

2.00 

1.70 

1.90 

2.10 

1.90 

1.80 

2.00 

2.00 

1.90 

1.90 

1.90 

2.10 

1.90 

2.10 

L4-ICP-MS 

2.05 

1.99 

2.12 

2.69 

3.29 

1.66 

2.01 

1.96 

1.76 

4.13 

2.07 

1.86 

2.03 

1.81 

2.19 

2.08 

1.84 

2.26 

L5-GD-MS 

1.65 

1.62 

1.33 

1.26 

1.24 

1.29 

1.66 

1.60 

1.97 

1.47 

1.67 

1.81 

L8-ICP-MS 

1.70 

1.80 

1.80 

1.60 

1.70 

1.70 

1.60 

1.50 

1.60 

1.60 

1.70 

1.80 

1.70 

1.60 

1.70 

1.70 

1.60 

1.60 

L9-ICP-MS 

2.18 

2.32 

2.60 

2.28 

2.15 

2.55 

2.46 

2.47 

2.39 

2.36 

3.03 

2.67 

2.42 

2.01 

2.24 

2.23 

2.11 

2.24 

L11-ICP-MS 

1.89 

2.11 

2.07 

1.93 

1.93 

1.96 

2.13 

2.03 

2.19 

2.05 

2.06 

2.16 

1.88 

2.01 

2.03 

2.13 

1.96 

1.92 

L13-GD-MS 

2.07 

2.15 

2.13 

2.05 

2.17 

2.14 

2.19 

2.17 

2.17 

2.23 

2.15 

2.24 

L16-ICP-MS 

1.77 

1.44 

1.46 

1.48 

1.49 

1.54 

1.50 

1.02 

1.46 

1.53 

1.49 

1.43 

1.60 

1.64 

1.51 

1.51 

1.61 

1.82 

L17-ICP-MS 

1.81 

1.89 

2.04 

1.94 

2.24 

1.93 

1.99 

2.06 

1.91 

2.09 

2.06 

1.93 

1.97 

1.86 

1.97 

2.31 

1.87 

2.30 

L18-ICP-MS 

3.69 

2.20 

2.99 

3.05 

2.91 

2.73 

2.85 

3.22 

3.29 

2.81 

2.04 

2.08 

2.75 

2.53 

3.25 

2.88 

2.88 

2.53 

Results not used for certification 

L1-ICP-MS 

2.86 

3.10 

3.32 

< 2.9 

< 2.9 

4.29 

3.84 

< 2.9 

2.97 

2.94 

< 2.9 

4.06 

3.39 

4.37 

3.71 

3.55 

2.88 

3.75 

L20-ICP-MS 

3.70 

3.80 

3.50 

3.60 

3.80 

4.20 

1.93 

2.21 

1.55 

1.67 

2.37 

2.03 

2.16 

1.52 

2.01 

2.82 

3.50 

3.77 

0.24 

1.25 

0.22 

0.17 

0.47 

0.51 

0.11 

0.21 

0.39 

0.86 

1.04 

0.48 

86 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E12.  Mean  Mg  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

87 

 
 
 
Mn (Manganese) 

Table E13. Individual results for Mn mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.95 

0.90 

0.89 

0.83 

0.86 

0.86 

0.91 

0.64 

0.87 

0.98 

0.82 

0.89 

0.90 

0.88 

0.93 

0.90 

0.88 

0.93 

L2-ICP-OES 

0.94 

0.89 

0.90 

0.92 

0.96 

0.90 

0.92 

0.93 

0.92 

0.88 

0.94 

0.92 

0.92 

0.91 

0.88 

0.90 

0.91 

0.89 

L4-ICP-MS 

0.78 

0.90 

0.93 

0.78 

0.92 

0.73 

0.94 

0.75 

0.74 

0.95 

0.92 

0.74 

0.77 

0.75 

1.03 

0.92 

0.76 

0.94 

L9-ICP-MS 

0.91 

0.83 

0.84 

0.83 

0.87 

0.82 

0.81 

0.70 

0.70 

0.92 

0.88 

0.86 

0.82 

0.93 

0.84 

0.83 

0.87 

0.87 

L11-ICP-MS 

1.10 

1.10 

1.10 

1.10 

1.10 

1.10 

1.00 

1.10 

1.10 

1.10 

1.10 

1.00 

1.10 

1.10 

1.10 

1.00 

1.10 

1.00 

L13-GD-MS 

0.90 

0.94 

0.95 

0.91 

0.98 

0.94 

0.91 

0.95 

0.95 

0.92 

0.93 

0.91 

L16-ICP-OES 

0.99 

0.99 

0.99 

0.86 

0.88 

0.92 

1.05 

0.67 

0.92 

0.96 

0.99 

0.93 

0.96 

0.99 

0.96 

0.96 

0.90 

1.03 

L17-ICP-MS 

1.08 

0.92 

0.98 

0.85 

0.93 

0.82 

1.21 

0.85 

0.93 

0.96 

0.88 

0.89 

0.86 

0.94 

1.02 

0.84 

1.02 

L20-ICP-MS 

Results not used for certification 

1.00 

1.10 

1.00 

1.00 

1.00 

0.95 

L5-GD-MS 

0.78 

0.82 

0.85 

0.83 

0.80 

0.79 

0.85 

0.82 

0.74 

0.86 

0.84 

0.79 

L8-ICP-MS 

0.76 

0.76 

0.78 

0.77 

0.75 

0.76 

0.75 

0.77 

0.74 

0.78 

0.75 

0.76 

0.75 

0.79 

0.75 

0.77 

0.77 

0.78 

L18-ICP-MS 

0.98 

0.97 

0.96 

0.85 

0.92 

0.87 

0.86 

0.79 

0.83 

0.68 

0.61 

0.71 

0.89 

0.87 

0.88 

0.84 

0.85 

0.81 

L21-Spark-OES 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

< 1.5 

0.88 

0.91 

0.85 

0.84 

1.08 

0.93 

0.94 

0.94 

1.01 

0.81 

0.76 

0.84 

0.14 

0.04 

0.12 

0.17 

0.27 

0.05 

0.06 

0.12 

0.10 

0.10 

0.08 

0.20 

88 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E13.  Mean  Mn  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

89 

 
 
 
Ni (Nickel) 

Table E14. Individual results for Ni mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L2-ICP-OES 

0.70 

0.80 

0.90 

0.60 

0.70 

0.60 

0.70 

0.50 

0.60 

0.70 

0.80 

0.60 

0.60 

0.60 

0.70 

0.70 

0.70 

0.60 

0.67 

L3-ETV-ICP-OES 

0.68 

0.70 

0.65 

0.68 

0.65 

0.56 

0.55 

0.57 

0.60 

0.56 

0.67 

0.67 

0.65 

0.66 

0.74 

0.61 

0.59 

0.58 

0.59 

0.60 

0.63 

L5-GD-MS 

0.77 

0.68 

0.64 

0.58 

0.63 

0.53 

0.64 

0.61 

0.70 

0.63 

0.58 

0.65 

L7-DC-arc-OES 

0.50 

0.50 

0.90 

0.50 

0.50 

0.50 

L9-ICP-MS 

0.65 

0.60 

0.68 

0.51 

0.55 

0.50 

0.61 

0.55 

0.65 

0.58 

0.54 

0.75 

0.58 

0.50 

0.50 

0.54 

0.54 

0.54 

L11-ICP-MS 

0.59 

0.59 

0.61 

0.60 

0.51 

0.60 

0.64 

0.66 

0.63 

0.64 

0.65 

0.62 

0.64 

0.58 

0.70 

0.56 

0.55 

0.56 

L12-ICP-MS 

0.58 

0.47 

0.70 

0.56 

0.40 

0.52 

0.48 

0.65 

0.59 

0.55 

0.50 

0.47 

0.62 

0.63 

0.66 

0.51 

0.68 

0.68 

L13-GD-MS 

0.59 

0.60 

0.58 

0.51 

0.53 

0.53 

0.52 

0.61 

0.58 

0.55 

0.58 

0.57 

L16-ICP-MS 

0.71 

0.77 

0.68 

0.50 

0.54 

1.00 

0.68 

0.44 

0.59 

0.65 

0.66 

0.59 

0.75 

0.62 

0.62 

0.62 

0.59 

0.65 

L17-ICP-MS 

0.60 

0.58 

0.70 

0.51 

0.56 

0.52 

0.56 

0.59 

0.55 

0.60 

0.62 

0.57 

0.60 

0.55 

0.64 

0.66 

0.54 

0.66 

L20-ICP-MS 

0.60 

0.70 

0.70 

0.60 

0.60 

0.50 

L2-ICP-OES 

0.70 

0.80 

0.90 

0.60 

0.70 

0.60 

0.70 

0.50 

0.60 

0.70 

0.80 

0.60 

0.60 

0.60 

0.70 

0.70 

0.70 

0.60 

0.64 

0.57 

0.58 

0.61 

0.57 

0.56 

0.65 

0.59 

0.62 

0.67 

L3-ETV-ICP-OES 

0.68 

0.70 

0.65 

0.68 

0.65 

0.56 

0.55 

0.57 

0.60 

0.56 

0.67 

0.67 

0.65 

0.66 

0.74 

0.61 

0.59 

0.58 

0.59 

0.60 

0.63 

L5-GD-MS 

0.77 

0.68 

0.64 

0.58 

0.63 

0.53 

0.64 

0.61 

0.70 

0.63 

0.58 

0.65 

Results not used for certification 

L4-ICP-MS 

0.83 

0.78 

0.75 

4.27 

7.95 

0.56 

0.64 

0.41 

0.74 

0.57 

L8-ICP-MS 

0.62 

0.64 

0.61 

0.63 

0.61 

0.62 

0.64 

0.62 

0.62 

0.61 

0.62 

0.61 

0.62 

0.63 

0.63 

0.62 

0.62 

0.61 

L18-ICP-MS 

L1-ICP-MS 

L6-ICP-OES 

L21-Spark-OES 

0.68 

0.88 

< 1 

< 1 

0.63 

< 
0.69 

< 1 

< 1 

0.60 

0.51 

0.69 

0.77 

< 1 

< 1 

< 1 

< 1 

0.51 

< 
0.69 

< 1 

< 1 

0.48 

< 
0.69 

< 1 

< 1 

0.56 

0.70 

< 1 

< 1 

0.56 

< 
0.69 

< 1 

< 1 

0.55 

< 
0.69 

< 1 

< 1 

0.44 

0.71 

< 1 

< 1 

0.44 

< 
0.69 

1.00 

< 1 

0.49 

< 
0.69 

< 1 

< 1 

0.55 

< 
0.69 

< 1 

0.56 

< 
0.69 

< 1 

0.53 

< 
0.69 

< 1 

0.50 

< 
0.69 

< 1 

0.50 

0.69 

< 1 

0.46 

< 
0.69 

1.00 

0.64 

1.75 

0.62 

0.53 

0.74 

1.00 

0.19 

0.15 

0.10 

0.33 

0.12 

0.15 

0.11 

0.05 

0.10 

0.10 

0.15 

0.19 

0.15 

0.10 

2.60 

0.06 

0.13 

0.15 

0.00 

90 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E14.  Mean  Ni  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

91 

 
 
 
O (Oxygen) 

Table E15. Individual results for O mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L9-IGF-IR 

7.70 

6.50 

6.50 

6.90 

7.90 

5.60 

9.20 

10.00 

9.20 

8.90 

8.70 

6.40 

11.00 

11.00 

9.70 

11.00 

6.50 

7.80 

L11-IGF-IR 

6.48 

5.94 

6.39 

6.19 

6.22 

5.86 

8.46 

8.09 

8.29 

6.86 

7.09 

6.98 

7.32 

7.33 

7.08 

6.52 

6.65 

6.57 

L13-GD-MS 

10.74 

9.53 

9.78 

9.05 

8.70 

8.97 

10.24 

10.84 

10.24 

10.21 

10.44 

10.83 

Results not used for certification 

8.36 

6.91 

9.96 

1.67 

1.73 

1.25 

L1-IGF-IR 

< 10 

< 10 

11.00 

12.00 

< 10 

14.00 

27.00 

24.00 

124 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

35.33 

87.87 

L17-IGF-IR 

5.00 

6.20 

7.80 

6.50 

6.30 

8.60 

6.40 

4.40 

6.40 

92 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E15.  Mean  O  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents the mean of laboratory means,  while the broken lines represent the expanded uncertainty  of the mean of laboratory means. Each  laboratory is 
represented by its code. 

93 

 
 
 
 
 
 
P (Phosphorus) 

Table E16. Individual results for P mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L4-ICP-MS 

1.03 

2.16 

1.85 

1.84 

1.72 

1.22 

2.39 

2.05 

1.21 

0.93 

1.81 

2.03 

1.58 

L5-GD-MS 

1.75 

1.57 

1.02 

1.11 

1.08 

1.27 

1.14 

1.01 

1.82 

0.95 

1.07 

1.50 

L8-ICP-MS 

1.30 

1.40 

1.30 

1.30 

1.40 

1.30 

1.40 

1.30 

1.40 

1.50 

1.20 

1.30 

1.30 

1.40 

1.20 

1.20 

1.30 

1.40 

L11-ICP-MS 

1.70 

1.90 

1.50 

1.60 

1.60 

1.60 

1.70 

1.70 

1.70 

1.70 

1.80 

1.70 

1.70 

1.90 

1.70 

1.90 

1.70 

1.70 

L12-ICP-MS 

1.80 

1.90 

1.90 

1.60 

1.70 

1.40 

1.80 

1.90 

1.80 

2.00 

2.00 

1.60 

1.60 

1.90 

1.90 

2.00 

1.90 

1.60 

L13-GD-MS 

1.11 

1.35 

1.26 

1.37 

1.11 

1.31 

1.41 

1.15 

1.35 

1.43 

1.31 

1.29 

L16-ICP-MS 

1.34 

0.94 

1.33 

0.91 

0.95 

1.31 

1.12 

1.57 

1.07 

1.17 

1.41 

1.23 

0.88 

1.11 

1.13 

0.91 

1.42 

1.11 

L17-ICP-OES 

1.58 

1.58 

1.59 

1.76 

1.46 

1.60 

1.34 

1.58 

1.66 

1.80 

1.47 

1.58 

1.35 

1.57 

1.49 

1.72 

1.68 

L21-Spark-OES 

1.80 

1.70 

2.20 

1.50 

1.60 

2.10 

1.70 

2.00 

2.20 

2.20 

2.40 

2.00 

L4-ICP-MS 

1.03 

2.16 

1.85 

1.84 

1.72 

1.22 

2.39 

2.05 

1.21 

0.93 

1.81 

2.03 

1.58 

L5-GD-MS 

1.75 

1.57 

1.02 

1.11 

1.08 

1.27 

1.14 

1.01 

1.82 

0.95 

1.07 

1.50 

Results not used for certification 

L1-ICP-OES 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

L2-ICP-OES 

L6-ICP-OES 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

< 2 

< 5 

L9-ICP-MS 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

L1-ICP-OES 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

1.68 

1.27 

1.33 

1.71 

1.79 

1.29 

1.16 

1.58 

1.95 

1.68 

1.27 

0.80 

0.48 

0.13 

0.43 

0.20 

0.22 

0.35 

0.21 

0.57 

0.80 

0.48 

94 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E16.  Mean  P  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

95 

 
 
 
Pb (Lead) 

Table E17. Individual results for Pb mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L3-ETV-ICP-OES 

2.88 

2.81 

2.79 

2.80 

2.90 

2.64 

2.67 

2.67 

2.84 

2.76 

2.84 

2.82 

2.83 

2.80 

2.85 

2.77 

2.74 

2.71 

2.74 

2.70 

2.78 

L4-ICP-MS 

2.70 

2.65 

2.68 

2.38 

2.39 

2.37 

2.54 

2.45 

2.45 

2.55 

2.52 

2.52 

2.65 

2.68 

2.77 

2.57 

2.57 

2.61 

L5-GD-MS 

1.84 

2.37 

2.84 

2.74 

2.19 

2.17 

2.97 

2.78 

1.64 

3.31 

2.88 

2.33 

L6-ICP-MS 

3.40 

3.40 

3.30 

2.90 

2.90 

2.90 

3.20 

3.10 

3.10 

3.20 

3.00 

3.10 

3.10 

3.10 

3.00 

3.00 

3.20 

3.10 

L7-DC-arc-OES 

2.70 

2.40 

2.80 

2.80 

2.60 

2.70 

L9-ICP-MS 

2.90 

3.03 

2.87 

2.44 

2.38 

2.38 

2.59 

2.55 

2.59 

2.67 

2.64 

2.51 

2.54 

2.21 

2.51 

2.31 

2.35 

2.43 

L11-ICP-MS 

2.81 

2.78 

2.71 

2.43 

2.41 

2.42 

2.58 

2.58 

2.58 

2.47 

2.54 

2.56 

2.75 

2.84 

2.73 

2.74 

2.67 

2.73 

L12-ICP-MS 

2.71 

2.45 

2.80 

2.07 

2.23 

2.10 

2.23 

2.16 

2.15 

2.21 

2.27 

2.18 

2.33 

2.34 

2.40 

2.46 

2.35 

2.53 

L13-GD-MS 

2.71 

3.03 

3.21 

2.63 

2.66 

2.59 

3.08 

2.93 

2.93 

2.93 

3.04 

2.77 

L16-ICP-MS 

2.91 

2.86 

2.82 

2.25 

2.24 

2.41 

2.66 

1.91 

2.47 

2.56 

2.63 

2.56 

2.51 

2.64 

2.61 

2.61 

2.53 

2.66 

L17-ICP-MS 

2.92 

3.14 

3.17 

2.65 

2.62 

2.68 

2.84 

2.79 

2.82 

3.02 

2.94 

2.84 

2.81 

2.82 

2.81 

2.99 

2.86 

2.96 

Results not used for certification 

L1-ICP-MS 

3.16 

2.90 

2.80 

2.50 

2.25 

2.64 

2.64 

2.00 

2.74 

2.71 

2.26 

2.74 

2.91 

3.00 

2.79 

2.54 

2.80 

2.58 

L2-ICP-OES 

2.00 

1.90 

2.00 

1.50 

1.40 

1.50 

1.60 

1.70 

0.80 

1.50 

1.70 

1.90 

1.90 

1.80 

1.70 

1.90 

1.70 

1.70 

L8-ICP-MS 

2.70 

2.60 

2.80 

2.80 

2.70 

2.60 

2.90 

2.50 

2.60 

2.50 

2.60 

2.70 

2.80 

2.60 

2.70 

2.50 

2.60 

2.70 

L18-ICP-MS 

1.34 

1.48 

1.53 

1.47 

1.46 

1.43 

1.75 

1.48 

1.63 

1.46 

1.33 

1.45 

1.53 

1.67 

1.74 

1.73 

1.82 

1.85 

L20-ICP-MS 

4.80 

3.70 

3.50 

4.00 

4.20 

3.70 

L21-Spark-OES 

4.30 

3.90 

4.40 

3.70 

3.30 

4.30 

4.40 

5.00 

6.00 

5.10 

7.10 

4.80 

2.56 

2.51 

3.11 

2.67 

2.55 

2.63 

2.33 

2.88 

2.55 

2.87 

2.66 

1.68 

2.66 

1.56 

3.98 

4.69 

0.19 

0.08 

0.76 

0.31 

0.30 

0.51 

0.66 

0.45 

0.20 

0.10 

0.30 

0.57 

0.57 

0.27 

0.32 

0.94 

2.07 

96 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
]
g
k
/
g
m

[
n
o
i
t
c
a
r
f

s
s
a
m
b
P

4

3.5

3

2.5

2

1.5

1

0.5

0

S
M
-
P
C
I
-
2
1
L

-

S
M
D
G
-
5
L

S
M
-
P
C
I
-
6
1
L

S
M
-
P
C
I
-
9
L

S
M
-
P
C
I
-
4
L

S
M
-
P
C
I
-
1
1
L

S
E
O
-
c
r
a
-
C
D
-
7
L

S
E
O
-
P
C
I
-
V
T
E
-
3
L

S
M
-
P
C
I
-
7
1
L

-

S
M
D
G
-
3
1
L

S
M
-
P
C
I
-
6
L

0
2
L

Laboratory code / Method

Figure  E17.  Mean  Pb  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

97 

 
 
 
 
 
 
 
 
 
S (Sulphur) 

Table E18. Individual results for S mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L2-spark-OES 

2.63 

2.77 

2.37 

2.30 

2.87 

2.70 

2.23 

2.30 

L5-GD-MS 

4.02 

3.25 

2.60 

2.57 

2.47 

2.68 

2.79 

2.62 

3.44 

2.40 

2.57 

2.99 

L7-DC-arc-OES 

L9-IGF-IR 

4.00 

3.00 

4.00 

6.00 

5.00 

3.00 

2.30 

2.00 

1.70 

2.20 

2.00 

2.00 

L11-IGF-IR 

3.21 

3.32 

3.32 

3.35 

3.24 

3.21 

3.02 

3.02 

3.12 

3.39 

3.32 

3.57 

2.96 

3.24 

3.30 

3.69 

3.42 

3.56 

L13-GD-MS 

2.50 

2.69 

2.59 

2.65 

2.39 

2.53 

2.73 

2.55 

2.71 

2.75 

2.66 

2.84 

L21-Spark-OES 

3.80 

5.90 

5.50 

4.40 

3.80 

3.70 

6.40 

5.30 

5.60 

6.20 

6.00 

7.90 

Results not used for certification 

2.52 

2.87 

4.17 

2.03 

3.29 

2.63 

5.38 

0.49 

0.78 

2.34 

0.41 

0.82 

0.48 

2.53 

L1-C-IR 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

< 10 

L4-ICP-MS 

10.20 

3.23 

5.24 

5.28 

5.78 

5.31 

2.41 

7.55 

13.20 

4.38 

1.03 

13.00 

11.40 

5.69 

5.86 

9.23 

1.82 

6.51 

7.72 

98 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E18.  Mean  S  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  indicative  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  indicative  value.  Each 
laboratory is represented by its code. 

99 

 
 
 
Sb (Antimony) 

Table E19. Individual results for Sb mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.55 

0.57 

0.56 

0.57 

0.56 

0.49 

0.58 

0.40 

0.58 

0.60 

0.53 

0.56 

0.57 

0.63 

0.60 

0.58 

0.58 

0.57 

0.56 

L3-ETV-ICP-OES 

0.58 

0.61 

0.59 

0.60 

0.63 

0.49 

0.53 

0.52 

0.56 

0.53 

0.62 

0.60 

0.61 

0.60 

0.60 

0.56 

0.56 

0.58 

0.56 

0.53 

0.58 

L4-ICP-MS 

0.51 

0.54 

0.52 

0.51 

0.54 

0.52 

0.54 

0.51 

0.52 

0.55 

0.53 

0.52 

0.52 

0.51 

0.54 

0.54 

0.52 

0.54 

L6-ICP-MS 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.50 

0.50 

0.60 

0.60 

L7-DC-arc-OES 

0.40 

0.50 

0.50 

0.40 

0.50 

0.40 

L8-ICP-MS 

0.48 

0.51 

0.49 

0.49 

0.47 

0.48 

0.45 

0.48 

0.48 

0.48 

0.48 

0.47 

0.47 

0.47 

0.46 

0.49 

0.48 

0.46 

L9-ICP-MS 

0.61 

0.45 

0.58 

0.53 

0.52 

0.53 

0.61 

0.60 

0.63 

0.60 

0.55 

0.62 

0.67 

0.41 

0.49 

0.44 

0.45 

0.45 

L10-INAA 

0.57 

0.58 

0.57 

0.57 

0.58 

0.58 

0.57 

0.57 

0.57 

0.57 

0.57 

0.57 

0.58 

0.57 

0.56 

0.59 

0.57 

0.58 

L11-ICP-MS 

0.80 

0.76 

0.70 

0.78 

0.73 

0.76 

0.67 

0.66 

0.70 

0.68 

0.67 

0.66 

0.69 

0.59 

0.68 

0.70 

0.69 

0.67 

L13-GD-MS 

0.56 

0.60 

0.61 

0.59 

0.57 

0.57 

0.56 

0.54 

0.58 

0.63 

0.60 

0.57 

L14-INAA 

0.53 

0.53 

0.46 

0.53 

0.53 

0.53 

0.53 

0.53 

0.46 

0.53 

0.53 

0.53 

0.56 

0.50 

0.54 

0.55 

0.54 

L15-INAA 

0.58 

0.55 

0.54 

0.60 

0.59 

0.57 

0.58 

0.61 

0.59 

0.57 

0.58 

0.58 

0.60 

0.62 

0.59 

0.60 

0.60 

0.61 

L16-ICP-MS 

0.65 

0.73 

0.65 

0.56 

0.59 

0.60 

0.74 

0.47 

0.59 

0.66 

0.65 

0.62 

0.69 

0.62 

0.63 

0.63 

0.57 

0.66 

L17-ICP-MS 

0.57 

0.64 

0.65 

0.63 

0.64 

0.64 

0.63 

0.60 

0.62 

0.68 

0.67 

0.64 

0.62 

0.60 

0.66 

0.66 

0.64 

0.68 

L18-ICP-MS 

0.46 

0.48 

0.48 

0.48 

0.51 

0.48 

0.46 

0.40 

0.45 

0.40 

0.35 

0.41 

0.49 

0.51 

0.52 

0.51 

0.53 

0.52 

L20-ICP-MS 

Results not used for certification 

0.70 

0.60 

0.60 

0.70 

0.60 

0.70 

0.53 

0.59 

0.45 

0.48 

0.54 

0.57 

0.70 

0.58 

0.52 

0.59 

0.63 

0.64 

0.47 

0.65 

0.10 

0.11 

0.03 

0.06 

0.11 

0.05 

0.11 

0.02 

0.18 

0.04 

0.03 

0.01 

0.06 

0.04 

0.10 

0.11 

L5-GD-MS 

L2-ICP-OES 

L21-Spark-OES 

0.40 
< 1 
< 2 

0.47 
< 1 
< 2 

0.50 
< 1 
< 2 

0.55 
< 1 
< 2 

0.46 
< 1 
< 2 

0.48 
< 1 
< 2 

0.55 
< 1 
< 2 

0.52 
< 1 
< 2 

0.39 
< 1 
< 2 

0.59 
< 1 
< 2 

0.55 
< 1 
< 2 

0.49 
< 1 
< 2 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

0.50 

0.09 

100 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E19.  Mean  Sb  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

101 

 
 
 
 
Se (Selenium) 

Table E20. Individual results for Se mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L3-ETV-ICP-OES 

0.40 

0.45 

0.40 

0.44 

0.44 

0.39 

0.53 

0.43 

0.42 

0.40 

0.55 

0.48 

0.48 

0.48 

0.51 

0.72 

0.61 

0.63 

0.59 

0.58 

0.49 

L5-GD-MS 

0.43 

0.42 

0.45 

0.47 

0.39 

0.44 

0.51 

0.47 

0.41 

0.53 

0.44 

0.44 

L6-ICP-MS 

0.60 

0.50 

0.50 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.50 

0.60 

0.50 

0.50 

0.50 

0.50 

0.60 

0.50 

L9-ICP-MS 

0.59 

0.76 

0.70 

0.86 

0.84 

0.82 

0.60 

0.66 

0.42 

0.69 

0.74 

0.67 

0.58 

0.88 

0.78 

0.86 

0.87 

0.84 

L10-INAA 

0.52 

0.55 

0.51 

0.52 

0.52 

0.52 

0.52 

0.53 

0.53 

0.54 

0.52 

0.53 

0.56 

0.54 

0.52 

0.46 

0.52 

0.52 

L13-GD-MS 

0.43 

0.46 

0.44 

0.47 

0.42 

0.45 

0.43 

0.40 

0.47 

0.46 

0.45 

0.47 

L14-INAA 

0.50 

0.51 

0.40 

0.53 

0.51 

0.53 

0.49 

0.49 

0.52 

0.44 

0.49 

0.53 

0.53 

0.50 

0.54 

0.56 

0.50 

0.52 

L15-INAA 

0.39 

0.40 

0.38 

0.53 

0.55 

0.49 

0.48 

0.75 

0.53 

0.43 

0.46 

0.55 

0.43 

0.64 

0.53 

0.44 

0.57 

0.50 

L16-ICP-MS 

0.83 

0.75 

0.87 

0.78 

0.81 

0.83 

0.64 

0.67 

0.83 

1.00 

0.65 

0.62 

0.91 

0.91 

0.56 

0.89 

0.83 

0.69 

L17-ICP-MS 

0.56 

0.60 

0.55 

0.55 

0.58 

0.60 

0.60 

0.55 

0.56 

0.59 

0.60 

0.64 

0.54 

0.54 

0.60 

0.56 

0.59 

0.55 

L18-ICP-MS 

0.57 

0.58 

0.59 

0.54 

0.60 

0.53 

0.56 

0.51 

0.56 

0.46 

0.37 

0.48 

0.55 

0.59 

0.55 

0.55 

0.56 

0.50 

0.45 

0.56 

0.73 

0.52 

0.45 

0.51 

0.50 

0.78 

0.58 

0.54 

L3-ETV-ICP-OES 

0.40 

0.45 

0.40 

0.44 

0.44 

0.39 

0.53 

0.43 

0.42 

0.40 

0.55 

0.48 

0.48 

0.48 

0.51 

0.72 

0.61 

0.63 

0.59 

0.58 

0.49 

L5-GD-MS 

0.43 

0.42 

0.45 

0.47 

0.39 

0.44 

0.51 

0.47 

0.41 

0.53 

0.44 

0.44 

L6-ICP-MS 

0.60 

0.50 

0.50 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.60 

0.50 

0.60 

0.50 

0.50 

0.50 

0.50 

0.60 

0.50 

Results not used for certification 

L1-INAA 

0.38 

0.50 

0.52 

0.29 

0.54 

0.51 

0.45 

0.29 

0.45 

0.53 

0.55 

0.55 

0.44 

0.32 

0.51 

0.53 

0.46 

0.48 

L4-ICP-MS 

0.89 

0.39 

0.67 

0.18 

0.75 

0.31 

0.78 

0.37 

0.41 

0.72 

0.38 

0.26 

0.36 

0.25 

0.49 

0.58 

0.57 

0.65 

L8-ICP-MS 

0.38 

0.36 

0.38 

0.37 

0.37 

0.38 

0.36 

0.34 

0.38 

0.36 

0.37 

0.36 

0.38 

0.35 

0.37 

0.39 

0.37 

0.36 

L11-ICP-MS 

0.53 

0.50 

0.46 

0.49 

0.49 

0.42 

0.63 

0.48 

0.49 

0.53 

0.47 

0.40 

0.43 

0.49 

0.55 

0.42 

0.45 

0.46 

L20-ICP-MS 

L2-ICP-OES 

L7-DC-arc-OES 

L21-Spark-OES 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

< 1 

1.00 

1.00 

1.10 

1.10 

1.00 

1.00 

1.00 
< 1 
< 1 

1.20 
< 1 
< 1 

1.10 
< 1 
< 1 

1.20 
< 1 
< 1 

1.10 
< 1 
< 1 

1.00 
< 1 
< 1 

0.45 

0.56 

0.46 

0.50 

0.37 

0.48 

1.10 

0.24 

0.06 

0.10 

0.15 

0.04 

0.04 

0.04 

0.04 

0.38 

0.16 

0.11 

0.24 

0.06 

0.10 

0.17 

0.30 

0.04 

0.12 

0.18 

102 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E20.  Mean  Se  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

103 

 
 
 
 
Si (Silicon) 

Table E21. Individual results for Si mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1  Rep 2  Rep 3  Rep 4  Rep 5  Rep 6  Rep 7  Rep 8  Rep 9  Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg]  [mg/kg] 

[mg/kg] 

L5-GD-MS 

0.62 

0.49 

0.42 

0.61 

0.62 

0.53 

0.63 

0.63 

0.60 

0.57 

0.52 

0.55 

L8-ICP-MS 

1.60 

1.60 

1.70 

1.70 

1.60 

1.60 

1.60 

1.80 

1.80 

1.50 

1.70 

1.50 

1.40 

1.60 

1.60 

1.50 

1.60 

1.60 

L11-ICP-OES 

1.40 

1.60 

1.40 

1.40 

1.40 

1.40 

1.70 

1.70 

1.70 

1.70 

1.70 

1.70 

1.40 

1.50 

1.40 

1.30 

1.30 

1.30 

L16-ICP-MS 

1.46 

1.30 

1.23 

1.61 

1.29 

1.24 

1.12 

1.07 

1.62 

1.14 

1.24 

1.50 

1.29 

1.34 

1.12 

1.12 

1.46 

1.25 

L17-ICP-OES 

1.21 

1.18 

1.21 

1.21 

1.19 

1.22 

1.22 

1.24 

1.23 

1.23 

1.22 

1.26 

1.24 

1.24 

1.22 

1.24 

1.27 

0.57 

1.61 

1.50 

1.30 

1.23 

0.11 

0.16 

0.38 

0.31 

0.12 

Results not used for certification 

L6-ICP-OES 

2.20 

<2 

2.40 

3.70 

3.80 

4.50 

< 2 

3.40 

2.50 

< 2 

3.10 

4.80 

4.90 

3.40 

2.50 

2.50 

2.50 

2.00 

3.21 

1.92 

L1-ICP-OES 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

< 60 

L9-ICP-MS 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

< 5 

104 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E21.  Mean  Si  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents the mean of laboratory means,  while the broken lines represent the expanded uncertainty  of the mean of laboratory means. Each  laboratory is 
represented by its code. 

105 

 
 
 
Sn (Tin) 

Table E22. Individual results for Sn mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

2.24 

1.60 

1.62 

1.70 

1.06 

2.23 

1.38 

1.68 

2.04 

1.80 

1.63 

2.21 

1.64 

1.40 

1.61 

1.31 

L2-ICP-OES 

1.50 

1.40 

1.70 

1.10 

1.40 

1.00 

1.30 

1.40 

1.40 

1.30 

1.50 

1.40 

1.40 

1.40 

1.50 

1.50 

1.60 

1.50 

1.70 

1.41 

L3-ETV-ICP-OES 

1.41 

1.38 

1.34 

1.38 

1.37 

1.30 

1.28 

1.31 

1.34 

1.31 

1.39 

1.40 

1.39 

1.39 

1.42 

1.39 

1.35 

1.33 

1.35 

1.34 

1.36 

L4-ICP-MS 

1.58 

1.66 

1.67 

1.27 

1.38 

1.18 

1.61 

1.43 

1.47 

1.61 

1.60 

1.49 

1.53 

1.53 

1.68 

1.59 

1.49 

1.62 

L5-GD-MS 

1.01 

1.22 

1.37 

1.07 

0.93 

0.94 

1.35 

1.28 

0.91 

1.46 

1.35 

1.16 

L6-ICP-MS 

1.80 

1.70 

1.60 

1.40 

1.30 

1.40 

1.60 

1.70 

1.70 

1.50 

1.50 

1.70 

1.70 

1.50 

1.50 

1.50 

1.70 

1.50 

L7-DC-arc-OES 

1.60 

1.60 

1.70 

1.60 

1.50 

1.50 

L8-ICP-MS 

1.60 

1.30 

1.80 

1.50 

1.60 

1.60 

1.40 

1.50 

1.50 

1.70 

1.80 

1.70 

1.50 

1.60 

1.50 

1.60 

1.70 

1.80 

L9-ICP-MS 

2.08 

1.98 

2.11 

1.40 

1.25 

1.21 

1.83 

1.73 

1.83 

1.79 

1.43 

1.85 

1.90 

1.47 

1.50 

1.46 

1.50 

1.48 

L11-ICP-MS 

1.49 

1.52 

1.53 

1.31 

1.20 

1.15 

1.39 

1.39 

1.47 

1.54 

1.42 

1.51 

1.42 

1.50 

1.49 

1.42 

1.40 

1.37 

L13-GD-MS 

1.67 

1.85 

1.79 

1.34 

1.34 

1.33 

1.72 

1.70 

1.71 

1.72 

1.70 

1.62 

L16-ICP-MS 

1.19 

1.58 

1.42 

1.33 

1.25 

1.44 

1.24 

2.04 

1.66 

1.68 

1.73 

2.04 

1.02 

1.38 

1.87 

1.87 

1.75 

1.70 

L17-ICP-MS 

1.53 

1.74 

1.75 

1.26 

1.25 

1.30 

1.51 

1.53 

1.53 

1.65 

1.64 

1.51 

1.51 

1.51 

1.53 

1.66 

1.58 

1.65 

L18-ICP-MS 

1.49 

1.42 

1.63 

1.02 

1.08 

1.07 

1.01 

0.95 

0.99 

0.92 

0.81 

0.95 

1.23 

1.30 

1.32 

1.33 

1.36 

1.34 

L21-Spark-OES 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

<2 

Results not used for certification 

1.52 

1.17 

1.57 

1.58 

1.59 

1.66 

1.42 

1.62 

1.57 

1.54 

1.18 

0.68 

0.33 

0.10 

0.10 

0.43 

0.27 

0.15 

0.16 

0.33 

0.35 

0.18 

0.38 

0.39 

0.46 

106 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E22.  Mean  Sn  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  indicative  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  indicative  value.  Each 
laboratory is represented by its code. 

107 

 
 
 
Te (Tellurium) 

Table E23. Individual results for Te mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.57 

0.54 

0.46 

0.46 

0.57 

0.46 

0.48 

0.38 

0.48 

0.52 

0.48 

0.52 

0.45 

0.58 

0.52 

0.58 

0.55 

0.46 

0.50 

L3-ETV-ICP-OES 

0.36 

0.43 

0.38 

0.40 

0.40 

0.42 

0.51 

0.46 

0.46 

0.47 

0.58 

0.43 

0.44 

0.44 

0.45 

0.68 

0.59 

0.60 

0.57 

0.54 

0.47 

L4-ICP-MS 

0.47 

0.48 

0.48 

0.42 

0.43 

0.41 

0.48 

0.44 

0.46 

0.45 

0.43 

0.44 

0.47 

0.43 

0.48 

0.48 

0.45 

0.49 

L5-GD-MS 

0.39 

0.44 

0.45 

0.50 

0.38 

0.43 

0.51 

0.49 

0.39 

0.52 

0.49 

0.46 

L6-ICP-MS 

0.50 

0.50 

0.50 

0.50 

0.50 

0.60 

0.50 

0.50 

0.50 

0.50 

0.50 

0.50 

0.50 

0.50 

0.50 

0.50 

0.60 

0.50 

L8-ICP-MS 

0.54 

0.56 

0.58 

0.55 

0.55 

0.56 

0.55 

0.51 

0.56 

0.54 

0.53 

0.54 

0.59 

0.54 

0.52 

0.56 

0.57 

0.58 

L10-INAA 

0.54 

0.61 

0.67 

0.52 

0.47 

0.53 

0.59 

0.53 

0.59 

0.54 

0.47 

0.53 

0.51 

0.51 

0.48 

0.67 

0.56 

0.40 

L11-ICP-MS 

0.58 

0.65 

0.65 

0.52 

0.61 

0.51 

0.57 

0.54 

0.57 

0.62 

0.54 

0.60 

0.51 

0.64 

0.60 

0.52 

0.64 

0.61 

L13-GD-MS 

0.41 

0.56 

0.46 

0.54 

0.44 

0.48 

0.53 

0.43 

0.51 

0.53 

0.49 

0.46 

L14-INAA 

0.60 

0.55 

0.52 

0.56 

0.60 

0.57 

0.54 

0.50 

0.57 

0.53 

0.59 

0.55 

L16-ICP-MS 

0.23 

0.27 

0.30 

0.46 

0.38 

0.53 

0.21 

0.53 

0.48 

0.45 

0.41 

0.45 

0.23 

0.33 

0.43 

0.36 

0.59 

0.34 

L17-ICP-MS 

0.46 

0.51 

0.48 

0.51 

0.48 

0.52 

0.50 

0.50 

0.51 

0.52 

0.50 

0.50 

0.50 

0.52 

0.50 

0.50 

0.51 

0.50 

L18-ICP-MS 

0.49 

0.51 

0.49 

0.46 

0.48 

0.52 

0.42 

0.40 

0.45 

0.37 

0.33 

0.38 

0.53 

0.52 

0.55 

0.54 

0.58 

0.51 

L20-ICP-MS 

Results not used for certification 

L9-ICP-MS 

L2-ICP-OES 

L7-DC-arc-OES 

L21-Ispark-OES 

0.83 
< 2 

0.74 
< 2 

0.99 
< 2 

0.71 
< 2 

0.90 
< 2 

1.09 
< 2 

0.82 
< 2 

0.94 
< 2 

0.98 
< 2 

0.86 
< 2 

0.86 
< 2 

0.90 
< 2 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

< 3 

0.60 

0.80 

0.30 

0.80 

0.60 

0.40 

0.92 
< 2 
< 1 

0.71 
< 2 
< 1 

0.71 
< 2 
< 1 

0.69 
< 2 
< 1 

0.72 
< 2 
< 1 

0.70 
< 2 
< 1 

108 

0.11 

0.20 

0.03 

0.07 

0.06 

0.06 

0.14 

0.15 

0.09 

0.10 

0.38 

0.03 

0.14 

0.41 

0.46 

0.45 

0.51 

0.55 

0.54 

0.58 

0.49 

0.55 

0.39 

0.50 

0.47 

0.58 

0.84 

0.17 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E23.  Mean  Te  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

109 

 
 
 
 
Ti (Titanium) 

Table E24. Individual results for Ti mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

0.83 

0.88 

0.84 

0.91 

0.98 

1.05 

0.77 

0.58 

0.78 

0.79 

0.75 

0.80 

0.77 

0.80 

0.82 

0.80 

0.80 

0.82 

L2-ICP-OES 

0.80 

0.70 

0.90 

1.00 

0.90 

1.00 

0.70 

0.80 

0.70 

0.80 

0.90 

0.80 

0.70 

0.60 

0.80 

0.90 

1.00 

0.90 

L4-ICP-MS 

1.12 

1.35 

1.41 

1.22 

1.52 

1.23 

1.25 

1.05 

1.28 

1.42 

1.09 

1.13 

1.13 

1.13 

1.35 

1.24 

1.16 

1.11 

L5-GD-MS 

0.48 

0.69 

0.94 

0.83 

0.69 

0.77 

1.03 

1.08 

0.59 

1.11 

1.21 

0.86 

L8-ICP-MS 

1.10 

1.20 

1.00 

1.20 

1.10 

1.00 

1.10 

1.10 

1.10 

1.30 

1.30 

1.10 

1.00 

1.20 

1.20 

1.10 

1.10 

1.20 

L9-ICP-MS 

0.87 

1.00 

1.04 

1.04 

1.03 

0.96 

0.96 

1.04 

0.99 

1.06 

1.01 

0.96 

0.93 

0.95 

1.13 

0.94 

0.89 

0.88 

L11-ICP-MS 

1.13 

1.00 

1.02 

1.08 

1.08 

1.12 

0.88 

1.06 

1.11 

1.06 

1.04 

1.07 

0.96 

1.07 

1.17 

1.07 

1.21 

1.00 

L13-GD-MS 

0.88 

1.05 

0.99 

1.11 

0.82 

0.93 

1.06 

0.93 

1.12 

1.05 

1.08 

1.13 

L16-ICP-MS 

0.76 

0.59 

0.54 

0.84 

0.81 

0.82 

0.55 

0.47 

0.62 

0.63 

0.61 

0.57 

0.67 

0.67 

0.67 

0.67 

0.74 

0.74 

L17-ICP-MS 

0.48 

0.62 

0.71 

0.81 

0.90 

0.81 

0.52 

0.56 

0.58 

0.75 

0.75 

0.62 

0.58 

0.53 

0.63 

0.77 

0.62 

0.77 

L18-ICP-MS 

1.29 

1.13 

1.28 

1.25 

1.37 

1.20 

0.90 

1.04 

1.08 

0.82 

0.69 

0.76 

1.12 

1.16 

1.15 

1.06 

1.10 

1.03 

L20-ICP-MS 

1.30 

1.40 

1.30 

1.40 

1.20 

1.40 

0.82 

0.83 

1.23 

0.86 

1.13 

0.98 

1.06 

1.01 

0.67 

0.67 

1.08 

1.33 

0.19 

0.24 

0.18 

0.28 

0.11 

0.20 

0.27 

0.17 

0.08 

0.24 

0.37 

0.16 

110 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E24.  Mean  Ti  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

111 

 
 
 
 
Zn (Zinc) 

Table E25. Individual results for Zn mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10  Rep 11  Rep 12  Rep 13  Rep 14  Rep 15  Rep 16  Rep 17  Rep 18  Rep 19  Rep 20  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L2-ICP-OES 

3.60 

2.30 

2.90 

2.50 

2.70 

2.40 

2.60 

2.40 

2.60 

2.30 

2.80 

2.20 

2.80 

3.10 

2.20 

2.30 

3.00 

2.40 

L4-ICP-MS 

1.79 

2.48 

1.73 

4.02 

1.10 

1.61 

1.24 

1.34 

1.75 

2.41 

1.24 

1.95 

1.71 

1.94 

1.81 

1.46 

2.25 

L5-GD-MS 

2.51 

2.55 

2.37 

1.95 

1.90 

2.10 

2.27 

2.08 

2.62 

2.01 

2.20 

2.28 

L7-DC-arc-OES 

2.10 

2.10 

2.40 

2.10 

2.00 

2.00 

L10-INAA 

2.21 

2.39 

2.17 

1.92 

2.02 

2.19 

2.24 

2.12 

2.14 

2.31 

2.05 

2.07 

2.13 

2.30 

1.97 

2.24 

1.94 

2.30 

L11-ICP-MS 

1.98 

1.96 

1.96 

2.05 

2.06 

2.04 

1.97 

2.00 

2.06 

2.04 

1.98 

2.00 

2.19 

1.96 

1.95 

2.09 

1.97 

2.09 

L12-ICP-MS 

2.00 

2.70 

2.40 

1.90 

3.10 

2.70 

2.90 

2.10 

1.80 

2.30 

2.30 

2.50 

1.60 

2.70 

2.00 

2.20 

3.00 

2.10 

L13-GD-MS 

2.02 

1.84 

1.84 

1.61 

1.70 

1.74 

1.79 

1.83 

1.82 

1.72 

1.87 

1.84 

L14-INAA 

2.12 

2.14 

2.13 

2.23 

2.08 

2.19 

L15-INAA 

2.56 

2.19 

2.04 

1.96 

1.82 

2.61 

2.27 

2.09 

2.60 

2.24 

2.34 

2.35 

2.39 

2.37 

3.42 

2.29 

2.31 

2.03 

L16-ICP-MS 

2.08 

1.81 

1.69 

1.65 

1.46 

1.80 

1.74 

1.49 

1.94 

1.70 

1.74 

2.04 

1.97 

1.94 

1.76 

1.79 

1.94 

1.75 

L17-ICP-MS 

1.90 

1.96 

2.03 

1.84 

1.77 

1.71 

1.81 

1.98 

2.03 

2.02 

1.99 

1.89 

1.84 

1.88 

1.91 

2.05 

1.84 

2.08 

L18-ICP-MS 

3.42 

2.27 

3.93 

3.28 

3.20 

2.90 

3.02 

2.95 

3.82 

3.14 

2.52 

2.98 

3.37 

3.61 

3.80 

3.08 

3.33 

2.95 

L20-ICP-MS 

Results not used for certification 

2.10 

2.10 

2.20 

2.00 

2.20 

2.00 

L1-ICP-MS 

3.86 

3.02 

4.56 

4.17 

2.61 

3.43 

5.83 

2.29 

2.81 

3.06 

3.27 

8.72 

7.08 

7.72 

5.68 

6.73 

4.21 

5.02 

L8-ICP-MS 

3.80 

3.60 

3.90 

3.80 

3.70 

3.70 

3.90 

3.90 

3.80 

3.80 

3.90 

3.60 

3.90 

3.80 

3.80 

3.80 

3.70 

3.70 

L9-ICP-MS 

3.35 

3.76 

5.77 

2.76 

3.92 

3.62 

3.03 

1.52 

2.53 

2.42 

4.06 

3.96 

2.95 

3.24 

3.44 

3.48 

3.41 

3.60 

L6-ICP-MS 

< 2 

2.00 

< 2 

2.00 

2.00 

2.40 

< 2 

2.10 

2.00 

< 2 

2.00 

2.30 

2.60 

< 2 

< 2 

< 2 

2.20 

2.00 

L21-Ispark-OES 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

< 2.5 

2.62 

1.87 

2.24 

2.12 

2.15 

2.02 

2.35 

1.80 

2.15 

2.33 

1.79 

1.92 

3.20 

2.10 

4.67 

3.78 

3.38 

0.74 

1.40 

0.30 

0.29 

0.21 

0.51 

0.60 

0.15 

0.17 

0.20 

0.29 

0.22 

0.87 

0.18 

3.81 

0.38 

0.68 

112 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E25.  Mean  Zn  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  certified  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  certified  value.  Each 
laboratory is represented by its code. 

113 

 
 
 
Zr (Zirconium) 

Table E26. Individual results for Zr mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - 
Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10 

Rep 11  Rep 12  Rep 13 

Rep 14 

Rep 15 

Rep 16 

Rep 17 

Rep 18  Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L2-ICP-OES 

L4-ICP-MS 

L5-GD-MS 

6.10 

9.04 

3.18 

L10-INAA 

10.20 

6.20 

9.09 

5.05 

8.45 

L14-INAA 

9.81 

10.09 

L15-INAA 

16.30 

17.60 

L20-ICP-MS 

6.10 

9.11 

8.35 

8.59 

8.94 

7.11 

6.50 

8.95 

7.75 

6.70 

9.34 

5.89 

6.30 

8.89 

6.49 

11.30 

11.80 

11.10 

6.30 

9.30 

8.68 

9.33 

9.22 

10.29 

10.26 

10.59 

6.50 

8.99 

9.12 

9.44 

9.00 

6.70 

8.85 

3.68 

9.81 

10.26 

10.10 

13.30 

16.00 

14.40 

10.30 

12.80 

5.20 

9.24 

5.20 

5.20 

5.60 

9.25 

8.93 

8.88 

5.10 

8.90 

5.50 

9.28 

5.70 

9.29 

5.60 

8.90 

4.90 

5.86 

9.34 

9.09 

10.24 

10.45 

6.69 

7.13 

11.50 

9.91 

10.10 

9.29 

12.10 

10.50 

11.30 

9.22 

9.53 

10.19 

9.26 

8.02 

10.52 

9.33 

9.28 

9.34 

10.57 

10.80 

11.16 

10.13 

9.94 

8.33 

9.75 

10.30 

7.40 

8.50 

9.63 

7.10 

10.70 

10.50 

15.10 

11.78 

7.70 

8.00 

8.80 

7.92 

L1-ICP-MS 

< 0.13 

< 0.13 

< 0.13 

< 0.13 

< 0.13 

< 0.13 

< 0.13 

< 0.13 

0.18 

< 0.13 

< 0.13 

0.42 

< 0.13 

0.34 

1.09 

< 0.13 

< 0.13 

< 0.13 

0.51 

L8-ICP-MS 

L9-ICP-MS 

L11-ICP-MS 

L16-ICP-MS 

L18-ICP-MS 

1.30 

2.34 

4.53 

5.37 

0.12 

1.30 

2.35 

4.50 

4.40 

0.17 

1.30 

2.08 

4.21 

4.48 

0.07 

1.40 

2.35 

4.44 

4.31 

0.06 

1.20 

2.63 

4.24 

4.53 

0.07 

1.40 

2.27 

4.62 

3.90 

0.06 

1.30 

2.18 

4.32 

4.13 

0.06 

1.30 

2.11 

4.60 

3.00 

0.05 

1.30 

2.15 

4.58 

4.12 

0.06 

1.20 

2.55 

4.58 

4.48 

0.06 

1.40 

1.40 

1.30 

2.77 

2.80 

2.73 

4.47 

4.49 

4.50 

3.69 

3.93 

5.05 

0.09 

0.07 

0.06 

1.40 

2.63 

4.42 

4.98 

0.06 

1.40 

2.89 

4.36 

5.85 

0.08 

1.40 

2.52 

4.35 

5.85 

0.09 

1.10 

2.15 

4.52 

5.52 

0.08 

1.40 

1.32 

3.16 

2.48 

4.47 

4.46 

5.85 

4.64 

0.06 

0.08 

1.18 

0.24 

3.20 

1.50 

1.40 

3.00 

1.30 

0.81 

0.13 

0.50 

1.11 

0.74 

0.06 

114 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure  E26.  Mean  Zr  mass  fraction  in  ERM-EB074  reported  by  particpating  laboratories.  Error  bars  represent  expanded  uncertainties.  The  solid  line 
represents  the  indicative  value  (the  mean  of  laboratory  means),  while  the  broken  lines  represent  the  expanded  uncertainty  of  the  indicative  value.  Each 
laboratory is represented by its code. 

115 

 
 
 
Hg (Mercury) 

Table E27. Individual results for Hg mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10 

Rep 11 

Rep 12 

Rep 13 

Rep 14 

Rep 15 

Rep 16 

Rep 17 

Rep 18 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-CV-AAS 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

< 0.005 

L8-ICP-MS 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L9-ICP-MS 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L10-INAA 

< 0.07 

< 0.08 

< 0.07 

< 0.08 

< 0.09 

< 0.08 

< 0.08 

< 0.08 

< 0.07 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.09 

< 0.09 

< 0.09 

< 0.09 

< 0.09 

L11-ICP-MS 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L16-ICP-MS 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L18-ICP-MS 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

W (Tungsten) 

Table E28. Individual results for W mass fraction in ERM-EB074 provided by each laboratory. The mean value was calculated as the unweighted mean of all 
individual  results.  The  expanded  uncertainty  budget  equals  to  k  factor  (k  =  2)  multiplied  by  u  provided  by  the  laboratory  or  is  estimated  as  two  times  the 
standard deviation of the measurements (if u is not provided). 

Lab code - 
Method 

Rep 1 

Rep 2 

Rep 3 

Rep 4 

Rep 5 

Rep 6 

Rep 7 

Rep 8 

Rep 9 

Rep 10 

Rep 11 

Rep 12 

Rep 13 

Rep 14 

Rep 15 

Rep 16 

Rep 17 

Rep 18 

Mean 

Uncertainty 
(k=2) 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

[mg/kg] 

L1-ICP-MS 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

< 0.08 

0.08 

< 0.08 

< 0.08 

< 0.08 

L8-ICP-MS 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L4-ICP-MS 

L9-ICP-MS 

0.01 
< 0.25 

L11-ICP-MS 

< 0.1 

L16-ICP-MS 

< 0.1 

0.01 
< 0.25 

< 0.1 

< 0.1 

0.01 
< 0.25 

0.01 
< 0.25 

0.01 
< 0.25 

0.01 
< 0.25 

0.01 
< 0.25 

0.01 
< 0.25 

0.01 
< 0.25 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

0.01 
< 0.25 

< 0.1 

< 0.1 

0.01 
< 0.25 

0.01 
< 0.25 

0.05 
< 0.25 

< 0.25 

0.03 
< 0.25 

0.03 
< 0.25 

0.02 
< 0.25 

0.02 
< 0.25 

0.014 

0.015 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

< 0.1 

L18-ICP-MS 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

< 0.04 

116 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
European Commission 

The certification of trace elements mass fraction in electrolytic copper: ERM®-EB074A, B and C 

EUR 26890 EN – Joint Research Centre – Institute for Reference Materials and Measurements 
Title:  
Author(s): Thomas BACQUART, Thomas P.J. LINSINGER 
Luxembourg: Publications Office of the European Union 
2015 – 116 pp. – 21.0 x 29.7 cm 
EUR – Scientific and Technical Research series – ISSN 1831-9424 
ISBN 978-92-79-43606-2 
doi:10.2787/10090 

 
 
 
 
 
 
 
As the Commission's in-house science service, the Joint Research Centre's mission is to provide EU policies 
with independent, evidence-based scientific and technical support throughout the whole policy cycle. 

Working in close cooperation with policy Directorates-General, the JRC addresses key societal challenges 
while stimulating innovation through developing new methods, tools and standards, and sharing its know-
how with the Member States, the scientific community and international partners. 

Key policy areas include: environment and climate change; energy and transport; agriculture and food 
security; health and consumer protection; information society and digital agenda; safety and security, 
including nuclear; all supported through a cross-cutting and multi-disciplinary approach. 

L
A
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N
A
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2
6
8
9
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N
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doi:10.2787/10090 

ISBN: 978-92-79-43606-2