i

Certification of NIST Standard Reference

Material 1575a Pine Needles and Results

of an International Laboratory Comparison

Elizabeth A. Mackey, Donald A. Becker, Rabia O. Spatz, Rick L. Paul, Robert

R. Greenberg, Richard M. Lindstrom, Lee L. Yu, Laura J. Wood, Stephen E.

Long, W. Robert Kelly, Jacqueline L. Mann, Bruce S. MacDonald, Stephen A.

Wilson, Zoe A. Brown, Paul H. Briggs, and James Budhan

NIST Special Publication 260-156
ii
iii

NIST Special Publication 260-156

XXXX

Certification of NIST Standard Reference

Material 1575a Pine Needles and Results of an

International Laboratory Comparison

Elizabeth A. Mackey, Donald A. Becker, Rabia D. Oflaz, Rick L. Paul, Robert R. Greenberg, Richard

M. Lindstrom, Lee L. Yu, Laura J. Wood, Stephen E. Long, W. Robert Kelly, Jacqueline L. Mann

Analytical Chemistry Division

Chemical Science and Technology Laboratory

National Institute of Standards and Technology

Gaithersburg, MD 20899 USA

Bruce S. MacDonald

Standards Reference Materials Group

Technology Services

National Institute of Standards and Technology

Gaithersburg, MD 20899 USA

Stephen A. Wilson, Zoe A. Brown, Paul H. Briggs, and James Budhan

United States Geological Survey

Denver CO, 80225 USA

June 2004

U.S. Department of Commerce

Donald L. Evans, Secretary

Technology Administration

Phillip J. Bond, Under Secretary for Technology

National Institute of Standards and Technology

Arden L. Bement, Jr., Director
iv

Certain commercial entities, equipment, or materials may be identified in this

document in order to describe an experimental procedure or concept adequately. Such

identification is not intended to imply recommendation or endorsement by the

National Institute of Standards and Technology, nor is it intended to imply that the

entities, materials, or equipment are necessarily the best available for the purpose.

National Institute of Standards and Technology Special Publication 260-156

Natl. Inst. Stand. Technol. Spec. Publ. 260-156, 71 pages (June 2004)

CODEN: NSPUE2

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 2004

_________________________________________

For sale by the Superintendent of Documents, U.S. Government Printing Office

Internet: bookstore.gpo.gov — Phone: (202) 512-1800 — Fax: (202) 512-2250

Mail: Stop SSOP, Washington, DC 20402-0001
v

Contents

Abstract v

Acknowledgments vi

Introduction 1

Material Collection and Preparation 1

Experimental Procedures 3

Results and Discussion 8

Certification and Data Analysis 8

Interlaboratory Comparison Procedures

Interlaboratory Comparison Results

Summary and Conclusions

Appendix A Results of Certification Analyses of Individual Portions of SRM 1575a

Performed at NIST and at USGS

Appendix B Copy of the SRM 1575a Pine Needles Certificate of Analysis

Appendix C List of Participants in the ASTM Interlaboratory Comparison

Appendix D Analytical Results from Each Participant in the ASTM Interlaboratory

Comparison Coded by Participant Numbers

Appendix E Analytical Results for Each Element Reported by Participants Compared

with Certificate Values and Interlaboratory Averages
vi

ABSTRACT

NIST recently released SRM 1575a Pine Needles to replace the original SRM 1575 Pine Needles,

which was issued in 1976 and is now out of stock. This material is intended primarily for use in

the evaluation of inorganic analytical techniques used to determine element content of botanical

and agricultural materials that have a matrix similar to pine needles. The needles were collected in

North Carolina from freshly felled loblolly pine (Pinus taeda) trees of about the same age. The

needles were dried, ground, jet-milled, blended, sterilized, and bottled. Elemental analyses of this

material were performed at NIST using five analytical techniques and at the U.S. Geological

Survey in Denver, CO using three techniques. Selected data were used to provide certified mass

fraction values for twelve elements, reference values for eleven elements, and information values

for two elements. This material was also used as a test material for an international

interlaborartory comparison exercise for the determination of elemental composition sponsored

by the ASTM Task Group on Nuclear Methods of Chemical Analysis. A complete description

of the material collection and preparation, the results of analyses, the methods used to assign

certified, reference, and information values, and results of the interlaboratory comparison exercise

are presented and discussed in this report.

Key Words: certified value, interlaboratory comparison, pine needles, reference material, round

robin, Standard Reference Material (SRM), trace elements
vii

ACKNOWLEDGEMENTS

The authors wish to acknowledge the North Carolina State

University's Forest Nutrition Cooperative who under the direction of Research Assistant

Professor Daniel L. Kelting collected, dried, and coarse-ground the pine needles for SRM 1575a. 

We gratefully acknowledge the hard work done by Curtis Fales of the SRM Group who jetmilled, blended, and bottled this material in record time, under difficult conditions. The authors

gratefully acknowledge the assistance of the staff of the NIST Center for Neutron Research,

Operations Group during the activation analysis experiments. The NIST staff greatly

appreciates the opportunity to collaborate with the U.S. Geological Survey analysts without

whom certification of this material would not have been possible.
1

INTRODUCTION

In September of 2002, the National Institute of Standards and Technology (NIST) released

Standard Reference Material (SRM) 1575a Pine Needles. This material was provided to replace

NIST SRM 1575 Pine Needles, which is now out of stock. This renewal material is one of five

NIST agricultural certified reference materials that are intended for use in the evaluation of

analytical methods for the determination of element content of botanical materials. Analysis of

SRM 1575a Pine Needles presents a different analytical challenge as compared with the other

agricultural reference materials due to differences in both matrix and levels of some elements. For

example, mass fractions of B, Ca, K, and Fe are significantly lower than in the other botanical

SRMs whereas the mass fraction of Mn is significantly higher. 

The material was collected, dried, and ground by the Forest Nutrition Cooperative of North

Carolina State University and shipped to NIST for further processing and bottling.

Determination of the elemental composition of the material was accomplished through a

collaboration of NIST with the U.S. Geological Survey (USGS) Denver, CO. Scientists at NIST

used inductively coupled plasma mass spectrometry (ICP-MS), cold vapor isotope dilution mass

spectrometry (CV-IDMS), instrumental neutron activation analysis (INAA), prompt gamma-ray

activation analysis (PGAA), and three different radiochemical neutron activation analysis

(RNAA) procedures for the determination of 26 elements. Scientists at the USGS used INAA,

ICP-MS, and inductively coupled plasma atomic emission spectrometry (ICP-AES) for the

determination of 40 elements. Certified, reference, and information values were assigned

according to the criteria described in detail by May et al. (2000). Complete descriptions of the

collection, preparation, material analyses, data analysis, and certification of SRM 1575a Pine

Needles are presented in this report.

Prior to release of SRM 1575a Pine Needles, this material was used as the test material for an

international interlaboratory comparison exercise for the determination of element content. This

round robin was conducted under the auspices of the ASTM Task Group on Nuclear Methods of

Chemical Analysis. Each participant received one 6-g portion of SRM 1575a and one 6-g portion

of SRM 1547 Peach Leaves for use as a control material. Participants were instructed to report

mass fraction values based on the dry mass of the material and were instructed to determine the

dry mass by desiccator drying of separate portions over fresh magnesium perchlorate. The two

SRMs were shipped to the participants in March of 2002 and participants were asked to send

results by the end of August (2002). Fifteen labs from eight countries participated in the study

for the determination of element content and one additional laboratory provided results from

determinations of two radioisotopes. The results from these laboratories and complete

discussion of the study data also are presented in this report.

MATERIAL COLLECTION AND PREPRATION

The pine needles used to prepare SRM 1575a were collected, dried, and ground by members of
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the Forest Nutrition Cooperative of North Carolina State University. Approximately 70 kg of

pine needles were collected in North Carolina from freshly felled loblolly pine (Pinus taeda) trees

of about the same age. The pine needles were coarse-ground to pass through a 2-mm sieve and

dried for 48 h at 70 °C prior to shipment to NIST. At NIST, the material was jet milled to pass a

100-μm sieve and blended over the course of two weeks. The material was radiation sterilized by

exposure to 60Co (2.5 Mrad) for 5 h. After irradiation, the material was apportioned into amber

bottles containing approximately 50 g each. The material collected and processed filled about

1300 bottles. Bottles were randomly selected for certification analyses performed by NIST and

USGS scientists. Each analyst was provided with six to twelve bottles of SRM 1575a. The

bottles used for each analytical method are listed in Table 1. A total of 30 bottles were used for

analyses performed by 14 analysts: ten analysts from NIST and four from the USGS Denver,

CO.

Table 1. Bottle Numbers Used by Each for Certification Analyses.

Analyst Group Technique (Elements) Bottle Numbers

NIST INAA (Na, K, Mn, Cl, Al,

Mg, Ca)

29, 227, 260, 308, 522, 739, 803, 953,

986,1027, 1142, 1333

INAA (As, Ba, Ce, Co, Cr,

Cs, Fe, Rb, Sb, Sc, Se, Th, Zn)

66, 227, 308, 522, 606, 739, 953, 1142,

1333

RNAA (Cu, Cd) 66, 227, 308, 739, 803, 986, 1027, 1142,

1333

RNAA (P) 66, 522, 606, 739, 803, 865, 953, 986,

1027, 1224

RNAA (Hg) 29, 66, 308, 522, 606, 1142, 1224

PGAA (B, Cl, K) 66, 227, 308, 522, 739, 953, 986, 1027

ICP-MS (Ba, Cd, Ni, Pb) 83, 189, 356, 472, 708, 1107

CV-IDMS (Hg) 83, 189, 356, 472, 708, 1107

Freeze-drying (moisture) 66, 227, 308, 522, 739, 953

USGS ICP-AES 491, 619, 766, 824, 901, 1149, 1191, 1255

ICP-MS 491, 619, 766, 824, 901, 1149, 1191, 1255

Prior to analysis, each analyst determined the moisture content of the material using separate

portions from several different bottles. Two methods were used at NIST to dry portions

removed from previously unopened bottles of SRM 1575a: 

1.) desiccator drying over fresh MgClO4 for 120 h,

2.) freeze-drying at a condenser temperature of -50 °C and a pressure of 1 Pa using a

shelf temperature gradient beginning at -10 °C and increasing in 5 °C increments to a

maximum of +5 °C over the course of one week. 

A summary of the results of drying studies performed at NIST on those previously unopened

bottles of SRM 1575a is shown in Table 2. For each method the number of portions (n) is listed

together with the average relative mass lost (± 1 standard deviation, 1s). Results of these two
3

drying methods were similar and indicated the moisture content of this material shortly after

bottling was approximately 2.84% ± 0.17% (the average value ± 1s, for seventeen portions).

The value for moisture content will change with time, depending upon storage and local

laboratory conditions. Pelletized portions of SRM 1575a stored for nine months in sealed

polyethylene bags placed in plastic Petri dishes gained about 2.9% mass due to absorption of

moisture. Other analysts using portions of SRM 1575a removed from previously opened bottles

found that the moisture content of SRM 1575a had increased from approximately 2.8% (average

for five portions with 1s of 0.1%) to 3.05% (average for 8 portions with 1s of 0.01%) and others

found a change from 3.0% (average for six portions with 1s = 0.2%) to 3.6% (average for six

portions with 1s = 0.2%). See Table 2. It is recommended that analysts determine the moisture

content on separate individual portions from each bottle, for each use.

Table 2. Results of Initial Drying Study on Bottles of SRM 1575a

Technique n Moisture Content of

Unopened Bottles

Freeze-Drying 6 2.76% ± 0.04%

Desiccator Drying (MgClO4) 5 2.77% ± 0.11%

Desiccator Drying (MgClO4) 6 2.98% ± 0.21%

17 2.84% ± 0.17% Average

Technique n Moisture Content of

Previously Opened Bottles

Desiccator Drying (CaSO4) 8 3.05% ± 0.01%

(previously opened bottles)

Desiccator Drying (MgClO4) 6 3.6% ± 0.2%

(previously opened bottles)

EXPERIMENTAL PROCEDURES

Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) at NIST

In preparation for ICP-MS, one 0.5-g portion from each of six bottles of SRM 1575a Pine

Needles and two 0.5-g portions of SRM 1547 Peach Leaves were weighed into individual

microwave cells. Then, 5 mL of HNO3 and 1 mL of HF were added to each cell. Samples were

digested in a microwave oven using an eight-step program in which the power was increased from

250 W to 550 W over the course of 40 min. The temperature in the cells ranged from 80 °C up to

but not exceeding 90 °C. Each digest was quantitatively transferred to a pre-weighed

polyethylene bottle and diluted to a total mass of 50 g after the addition of an internal standard
4

consisting of 80 μg of Rh. From each diluted digest, 25 g were transferred to another

polyethylene bottle. One gram of a spike solution containing 0.991 μg/g Ni, 0.247 μg/g Cd, 0.832

μg/g Ba, and 0.486 μg/g Pb was added to each.

Prior to the quantitative determination of the elements of interest, an ICP-MS semi-quantitative

analysis was performed on un-spiked solutions of digested SRM 1575a and SRM 1547. These

results were used to assess the presence or absence of interferences, and to determine the

optimum concentrations for the spike. Molecular 44Ca16O was found to interfere with the

measurement of 60Ni, the isotope chosen for the quantification of Ni. A solution of 100 μg/g Ca

was analyzed with the samples and the ratio of the intensities at masses 60 and 43 was

calculated. This ratio was used to correct the measured intensity at mass 60 to obtain the

intensity from 60Ni. Similarly, 95Mo16O interfered with the determination of 111Cd, the isotope

used for quantification of Cd. A solution containing 50 μg/g Mo was analyzed with the samples

and the ratio of the intensities of masses 111 and 97 was calculated. This ratio was used to

correct the measured intensity at 111, to account for this interference in determining the mass

fraction of Cd. No spectral interferences were found for the isotopes used to quantify Ba or Pb.

Blanks were included in the analysis scheme and element mass fraction values were corrected for

any amounts present in the blanks. Blank corrections were required for Ni, Ba, Cd, and Pb.

Cold Vapor-Isotope Dilution Mass Spectrometry (CV-IDMS) at NIST

Analysis of Hg was performed by CV-IDMS of samples prepared using a Carius tube sample

digestion. This sample decomposition method has been described in detail elsewhere (Long, et

al., 2002) and a brief description is included here. Approximately 0.25 g of sample from each

bottle was weighed into a cleaned Carius tube and spiked with a weighed aliquot of 201Hg

followed by the addition of 5 mL of high-purity HNO3. Each vessel was flame-sealed, placed in

a steel cylinder along with 20 g of solid CO2 for external pressurization, and heated in a

convection oven at 240 °C for 12 h. After cooling to room temperature, each vessel was

depressurized using a high-temperature flame, the contents transferred to polypropylene

centrifuge tubes, and diluted to a concentration of approximately 0.25 ng/g Hg. The tubes were

stored at 4 °C overnight to allow degassing of NO2 and CO2. Analyses were performed within

24 h using cold vapor Hg generation followed by ICP-MS isotope ratio measurements.

This CV-IDMS method has been described in detail elsewhere (Christopher, et al., 2001) and a

brief description is included here. The Hg vapor was generated using a 10% (mass/volume) SnCl2

in 7% (volume fraction) HCl reductant, and separated from the liquid phase using a commercially

available reaction separator cell. The vapor was transferred to an ICP-MS system using 100

mL/min of Ar(g). The gas stream was mixed with the plasma injector gas stream using a plastic T

piece. The ICP was operated in a dry plasma mode. The 201Hg and 202Hg isotopes were

monitored in a pulse counting, Time-Resolved-Analysis mode to recover the individual ion count

rates. Background corrected ratios were calculated from the isotope-time profiles. Instrument

mass discrimination was measured by generation of Hg vapor from an isotopic calibration

standard. The mass discrimination factor was close to unity during the measurement period
5

owing to the high mass of the isotopes and the lens settings used. The 201Hg isotopic spike

solution was calibrated by reverse isotope dilution using a high-purity primary standard, SRM

1641d Mercury in Water. Two separate stock solutions were prepared by serial dilution of the

standard. Results of CV ICP-MS showed that the spike contained 0.5702 nmol/g Hg (± 0.095%,

1s). Results for samples were corrected for

42 pg of Hg in the procedural blank.

Instrumental Neutron Activation Analysis (INAA) at NIST

In preparation for INAA, one portion weighing between 200 mg and 250 mg from each bottle of

SRM 1575a was formed into a disk-shaped pellet using a commercially available stainless steel

die and hydraulic press. Each disk was doubly encapsulated in bags formed from acid-washed

polyethylene film. Element standards consisted of filter papers onto which solutions containing a

known amount of the analyte of interest had been deposited and dried. Two portions each of

SRM 1547 Peach Leaves and SRM 1575 Pine Needles were included in the analysis for the

purpose of quality control. These quality control SRMs were prepared and packaged in the same

manner as the portions of SRM 1575a. 

For analysis of short-lived products of neutron irradiation, one sample or control SRM or

element standard was irradiated individually for 60 s in the NIST reactor using neutron irradiation

tube facility RT-4, which exposed the sample, or sample and standard, to a thermal neutron

fluence rate of 3.5 x 1013 cm-2.s-1. After irradiation, the sample, control, or standard was removed

from the irradiation container and polyethylene bag and repackaged in clean (un-irradiated)

polyethylene film. Gamma spectrometry was performed on each using a system that consisted

of a germanium detector, 16K channel, fixed conversion time, analog-to-digital converter linked to

a multichannel analyzer. Gamma radiations were collected for 5 min, after a decay time of 5 min,

at a distance of 20 cm from the end of the detector for the determination of Al, Ca, and Mg. 

Using the same detector and geometry, gamma radiations were collected again for 5 min, after 15

min of decay, for the determination of Cl, and for a third time for 1 h, after 1 h to 5 h of decay for

the determination of Na, K, and Mn. Data reduction was accomplished using commercially

available software to determine peak areas and to calculate the activity at the end of irradiation. 

Element mass fraction values were calculated based on comparison with standards.

For determination of long-lived products of neutron irradiation, separate 200-mg portions of

SRM 1575a and control SRMs were prepared and packaged in the same manner. Element

standards consisted of either pure metal foils of known mass or filter papers onto which

solutions containing known amounts of the elements of interest had been deposited. All SRMs

and standards were placed in one of two polyethylene irradiation containers. Iron foils were

included in the top and bottom of the irradiation vessel to monitor any differences in neutron

fluence over the length of the container. Each container was subjected to a neutron fluence rate of

3.5 x 1013 cm-2.s-1 for 3 h. Halfway through the neutron irradiation, each container was inverted

end-over-end and then reinserted into the reactor. This procedure serves to minimize differences

in neutron exposure among the samples and standards due to a linear drop off of the neutron
6

fluence rate with distance from the reactor core. All irradiated samples and standards were

allowed to decay for 4 d to 5 d to eliminate or decrease the activity from short-lived isotopes. 

Then, each portion was removed from the irradiation vessel and from the irradiated polyethylene

bags and placed in another polyethylene bag for gamma spectroscopy. Gamma-ray

spectroscopy was performed using a germanium detector (40% efficiency relative to a standardsized NaI crystal) and associated electronics. For the analysis of As, samples, standards, and

controls were counted individually on the germanium detection system for 2 h to 8 h. After

additional decay times of two to three weeks, each individual sample, control, or standard was

counted for a minimum of 8 h and as long as 24 h for the analysis of Ba, Ce, Co, Cr, Cs, Fe, Rb,

Sb, Sc, Se, Th, and Zn. Quantification was based on comparison with elemental standards. Count

rates for the Fe fluence-rate monitors, corrected for decay time and mass differences, agreed

within 0.5%, indicating that the two containers were exposed to the same neutron irradiation

dose.

Prompt Gamma-Ray Activation Analysis (PGAA) at NIST

For PGAA, one portion weighing between 740 mg and 760 mg was removed from each of eight

bottles. Each portion was formed into a disk using a commercially available stainless steel die and

hydraulic press, and each disk was packaged in a bag formed from Teflon film. Two portions of

SRM 1547 were prepared in the same manner and included for the purpose of quality control.

Standards consisted of filter papers onto which solutions containing known amounts of the

elements of interest had been deposited. The filter papers were formed into disks and packaged in

bags formed from Teflon film so that the geometry of the samples and standards was identical. 

Each disk of the SRM was simultaneously irradiated and counted for 8 h to 24 h, and standards

for 0.5 h to 1 h, in the new thermal neutron PGAA instrument at vertical beam tube VT-5. A Ti

foil was irradiated before and after each sample to monitor any fluctuations in the neutron fluence

rate of VT-5. Over the two-week interval required for this analysis, results of the Ti foil monitor

irradiations showed that any variations in neutron fluence rate were ≤0.9%. Quantification was

based on comparison with elemental standards. All data were corrected for the effects of the pile

up of pulses at higher count rates. Results for B were corrected for the presence of this element

in the background which was equivalent to 0.7 μg of B. The H content of the standards and the

samples were nearly identical so that no corrections for neutron scattering were required.

Radiochemical Neutron Activation Analysis (RNAA) for Cu and Cd at NIST

Sample, control, and standard preparation were the same for RNAA as described for INAA at

NIST. Two portions of SRM 1547 Peach Leaves and two portions of SRM 1570a Trace

Elements in Spinach Leaves were included as control materials. The portions of all SRMs and

element standards were placed in one of two polyethylene irradiation containers or "rabbits". 

Iron foils were included in the top and bottom of each rabbit to monitor any differences in

neutron fluence over the length of the rabbit and between rabbits. Each rabbit was subjected to a

neutron fluence rate of 3.5 x 1013 cm-2.s-1 for 2 h. Halfway through the neutron irradiation, each

rabbit was inverted end-over-end and then reinserted into the reactor to minimize differences in
7

neutron exposure among the samples and standards.

This RNAA method has been described in detail elsewhere (Greenberg, 1986) and a brief

description is included here. After a decay time of 52 h to 54 h, each portion was removed from

the irradiation container and from the polyethylene bags, and placed in a Teflon beaker containing

10 mL of concentrated HNO3, 10 mL of H2O, and 0.1 mL of a carrier solution. The carrier

solution contained 5 mg/mL Cu and 5 mg/mL Cd. Each Teflon beaker was placed on a hot plate

with a surface temperature of 150 °C to 200 °C until the volumes were reduced to approximately

0.5 mL. An additional 10 mL of HNO3 and 10 mL of HClO4 were then added to each beaker and

the beakers were covered with Teflon lids. After 1 h, the lids were removed and the surface

temperature of the hot plate increased to approximately 180 °C to 220 °C. Beakers were

removed from the hot plate when the volumes were reduced to approximately 0.5 mL. Again, 10

mL of HNO3 and 10 mL of HClO4 were added to each beaker. The beakers were covered and

placed on a hot plate with a surface temperature of about 120 °C overnight. The following

morning, the lids were removed and the surface temperature of the hot plate was increased to a

temperature between 180 °C and 220 °C. After approximately 1 h, 1 mL of HF was added to

each sample or standard. When volumes were reduced to 0.5 mL the beakers were removed from

the hot plate.

Radiochemical separations consisted of adding 10 mL of 1 mol/L HNO3 to each 0.5 mL digest and

adjusting the pH to a value between 1.5 and 1.7. The diluted digest was added to a separatory

funnel. The Cu and Cd were extracted with one 25 mL portion followed by one 5 mL portion of a

solution containing 2 g/L of zinc diethyldithiocarbamate [Zn(DDC)2] in chloroform. The

Zn(DDC)2 layer was drained into a second separatory funnel containing 25 mL of 2.5 mol/L HCl.

This funnel was shaken for 30 s to back extract the Cd into the aqueous layer. The lower organic

layer containing Cu was drained into a high-density polyethylene (HDPE) bottle and the upper

aqueous layer containing Cd was transferred to another HDPE bottle. Gamma-ray spectroscopy

was performed on each separated fraction using a germanium detector and associated electronics. 

For the assay of Cu, gamma radiations were collected for 0.5 h to 2 h. For the assay of Cd,

gamma radiation was collected for 2 h to 8 h after allowing 24 h for the 115Cd (half-life, t1/2 = 53.4

h) and 115In (t1/2 = 4.49 h) isotopes to reach equilibrium. Quantification was based on

comparison with standards. Count rates for the Fe fluence-rate monitors, corrected for decay

time and mass differences, agreed within 2%, indicating that the two containers experienced the

same neutron dose.

Radiochemical Neutron Activation Analysis (RNAA) for P at NIST

Standards were prepared by depositing solutions containing known amounts of P onto 40 mg

pieces of aluminum foil, which were dried by heating under an infrared lamp. These were

packaged in bags formed from clean polyethylene film. Sample and control SRMs were prepared

and packaged as described for INAA. Samples, controls, and standards were subjected to a

neutron fluence rate of 2.7 x 1013 cm-2.s-1 for 5 min and were allowed to decay for approximately

one week prior to radiochemical separation. Zinc foils were included in each irradiation container
8

to monitor any differences in the neutron exposure within a container and among different

containers.

Samples or controls were placed in beakers containing 7.02 mg of P (non-radioactive carrier),

10 mL concentrated HNO3, and 10 mL H2O, covered, and heated for about 16 h and then allowed

to evaporate to near dryness. This procedure was followed by heating in covered beakers with

10 mL of HNO3, 10 mL of HClO4, and 10 drops of HF for 16 h, followed by evaporation to near

dryness. Standards were subjected to a similar digestion procedure that also included the addition

of 7 mL of HCl in the initial step. The residue from each was dissolved in 10 mL of HNO3 and 30

mL of H2O, and the standards were filtered to remove any insoluble material. To each sample,

control or standard, 5 g of NH4NO3 and 20 mL of a solution containing10% (mass/volume)

NH4MoO3 were added to precipitate (NH4)3PO4

.

12MoO3. The precipitates were collected,

washed twice with 15 mL of H2O, and then dissolved in 10 mL of NH4OH. To each were added

20 mL of H2O, 10 mL of 20% (mass/volume) NH4Cl and 15 mL of a magnesia reagent to

precipitate MgNH4PO4 overnight. The precipitate was collected, washed, dried, and transferred

to a planchet. Each sample, standard and control was counted using a b- proportional counter. 

After counting, the precipitate was transferred to a crucible and heated at 650 °C for at least 1 h

to convert the compound to Mg2P2O7. The yields were determined gravimetrically from the

masses of MgNH4PO4 and again from the masses of Mg2P2O7.

Radiochemical purity was determined by both gamma-ray screening and by b- analysis of

activity as a function of time over the course of four half-lives. Count rates were corrected for

the effects of self-absorption of b- particles in the precipitate. Mass fractions were determined

using decay-corrected count rates based on comparison with standards.

Radiochemical Neutron Activation Analysis (RNAA) for Hg at NIST

Portions of SRM 1575a weighing from 160 mg to 250 mg were removed from the bottles and

flame-sealed in quartz vials. Control materials were prepared in the same manner. Standards were

prepared by depositing solutions containing known amounts of Hg onto cysteine-impregnated

filter paper. The filter papers were dried at room temperature and encapsulated in quartz vials.

The standards, samples, and controls were exposed to a neutron flux of 7.7 x 1013 cm-2.s-1 for 6 h.

After irradiation, the short-lived activities in the samples were allowed to decay before they were

processed radiochemically. Each quartz vial was rinsed sequentially in HNO3 and water, frozen

in liquid nitrogen, wrapped in tissue, and crushed. In a quartz combustion tube, the package was

burned in an unglazed porcelain boat with about 50 mg of HgO carrier. The sample and tissue

were slowly ignited with a hand torch at an airflow of 100 mL/min and the oxidation completed in

an oxygen flow of 100 mL/min for 10 min in a 700 °C furnace. The products of combustion were

trapped at liquid nitrogen temperature, rinsed into a polyethylene bottle with 5 mL of HNO3 and

diluted to 50 mL for preliminary gamma assay. After adding 1 mg of Se holdback carrier, the

solution was evaporated, taken up in 100 mL of hot 0.15 mol/L HNO3, and mercury periodate

precipitated with 1.0 g of Na3H2IO6. After digestion, the precipitate was collected, washed, and
9

mounted in a Petri dish for gamma spectrometry. Yields were determined based on the mass of

dried Hg5(IO6)2, and mass fractions of Hg were determined based on comparison with standards.

Inductively Coupled Plasma Mass Spectrometry (ICP-MS) at the USGS

This procedure has been described in detail in U.S. Geological Survey Open File Report 02-223-I

and a brief summary is included here. Samples and control materials (including SRM 1547 Peach

Leaves) were decomposed using a mixture of HCl, HNO3, HClO4, and HF at low temperatures,

brought to dryness, and then dissolved using 1 mL of HClO4 and two drops of H2O2. Each

digest was diluted with 19 mL of 1% (volume fraction) HNO3, heated for 30 min, and further

diluted 1:10 with 1% (volume fraction) HNO3. Internal standards containing known amounts of

Li, Rh, and Ir in 1% HNO3 were added to each sample solution prior to analysis. A dual detector

calibration and auto-lens adjustment were performed according to manufacturer’s

recommendations. Two multi-element solutions were used for calibration. 

Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) at USGS

This procedure has been described in detail in U.S. Geological Survey Open File Report

02-223-G and a brief summary is included here. One 200-mg portion of each sample and control

material (SRM 1547 Peach Leaves) was added to a Teflon vessel together with an internal

standard consisting of 50 μg Lu in HCl. Samples and control materials were decomposed using a

mixture of HCl, HNO3, HClO4, and HF at low temperatures and evaporated to dryness. The

dried samples were dissolved in 1 mL of aqua regia and 9 mL of 1% (volume fraction) HNO3. 

The ICP-AES instrument was calibrated prior to sample analysis using several single and multielement standard solutions. The digested samples were aspirated into the ICP-AES discharge

where the elemental emission signals were measured simultaneously for all elements determined. 

Method blanks were included, and blank subtractions performed where necessary. Inter-element

correction factors and background corrections were applied using commercially available

software. 

RESULTS AND DISCUSSION

Quality Assurance

All analysts from NIST and the USGS included portions of either SRM 1575 Pine Needles or

SRM 1547 Peach Leaves or both in the analysis scheme for the purpose of quality assurance.

Portions of SRM 1570a were included for analyses of Cu and Cd at NIST. Results from these

analyses agreed with the certified values within the associated uncertainties for all materials for all

elements analyzed at NIST and for most elements analyzed at USGS. In a few cases where data

did not agree with certified values for a given element, data for that element were not used to

assign values for SRM 1575a Pine Needles. A summary of the results from analyses of SRMs

1575 and 1547 are shown in Table 3. 
10

Analytical Results for SRM 1575a Pine Needles

Analyses were performed at NIST using INAA, RNAA, PGAA, ICP-MS, and CVIDMS. The

results from analyses of individual portions expressed on a dry mass basis are listed in Appendix

A. Analyses were performed at USGS Denver using ICP-MS, ICP-AES, and INAA. Selected

data from USGS, obtained using methods independent of those used at NIST (i.e., methods other

than those used at NIST) were used to calculate certificate values. Results from USGS from

analyses of individual portions for data used to calculate certificate values are included in

Appendix A. Additional data from USGS were used to confirm NIST values but are not included

here. Where two NIST methods were available only those data were used to calculate the

certificate values for SRM 1575a. The average values (± 1s) from each technique and each

laboratory that were combined to provide certified values are listed in Table 4.

Material homogeneity was assessed based on results from INAA of 10 to 24 200 mg portions

analyzed at NIST. These results indicated that SRM 1575a is not homogenous with respect to

Cr content for this sample size. The range of values obtained from analyses of individual

portions was 0.3 mg/kg to 0.5 mg/kg. Results from analyses performed at USGS were similar. 

No other elements were found to be inhomogeneous at this sample size.
11

CERTIFICATION AND DATA ANALYSIS

Certificate values for SRM 1575a are designated as certified, reference, or information according

to the modes defined by May et al. (2000) in NIST SP 260-136. The modes used to provide

certified, reference, and information values for this material are described briefly here. The

certified value for Hg is based on results from one primary method (CV-IDMS). Results from

RNAA confirm this value but were not included in the calculation to determine the certified

value. All other certified values are based on results from two or more critically evaluated

independent analytical techniques. A NIST certified value is a value for which NIST has the

highest confidence in its accuracy in that all known or suspected sources of bias have been

accounted for or investigated. Reference values for this material are based on results obtained

from a single NIST analytical method, either INAA or ICPMS. Reference values are noncertified values that are the best estimate of the true values but do not meet NIST criteria for

certification. Reference values are provided with associated uncertainties that may not include all

sources of uncertainty. Information values were provided for two elements, Cr and Ce. These

are noncertified values with no uncertainty assessed. The information value for Ce is based on

results from one NIST method (INAA). Results from several different techniques indicated that

Cr is distributed inhomogenously when measured in several 200 mg portions. For this reason, a

Cr mass fraction range is given for information purposes and this range is based on results from

both NIST and USGS. 

Data from two or more techniques were combined to provide the certified values using the

method described by Levenson et al. (2000). This method assumes a type B distribution of any

bias between the methods. The formulae defined by Levenson et al. that were used to combine

these results into a certified mass fraction value (X) and expanded uncertainty (U) are shown

here:

1. X = 1/2(x1 + x2) for two values or 1/3(x1 + x2 + x3) for three values

2. U = k[u(B)2 + u(X)2]

0.5

3. u(X) = [u(x1)

2

/4 + u(x2)

2

/4 ]0.5

4. u(B) = |x1 - x2|/(2(3)0.5)

In those formulae, u(B) is the standard uncertainty of the combined value assuming a rectangular

distribution, and u(X) is the combination of the individual within-method uncertainties of the two

methods. These combined mass fraction and uncertainty values are listed as certified values in

the last column of Table 4. A copy of the Certificate of Analysis for SRM 1575a Pine Needles is

included as Appendix B.

13

Table 3. Results from Analyses of SRMs 1575 Pine Needles and 1547 Peach Leaves Included with Analyses of SRM 1575a.

Methods are listed in Table 4. 

SRM 1575 SRM 1547

Element (units) Method 1 Method 2 Certificate Values Method 1 Method 2 Certificate Value

Al (μg/g) 603 ± 20 590 545 ± 30 250 ± 9 270 249 ± 8

As (μg/g) 0.20 ± 0.02 0.21 ± 0.04 0.065 ± 0.014 0.060 ± 0.018

B (μg/g) not analyzed 27.8 ± 1.3 29 ± 2

Ba (μg/g) 7.4 ± 0.1 not analyzed 128 ± 10 127 ± 4 124 ± 4

Cd (μg/g) See 1570a below not analyzed <0.5 (non-certified) 0.032 ± 0.012 0.026 ± 0.003 0.026 ± 0.003

Ca (%) 0.41 ± 0.02 0.413 0.41% ± 0.02% 1.57 ± 0.07 1.63 1.56% ± 0.02%

Ce (μg/g) 0.27 0.4 (non-certified) 11.3 ± 0.5 10 (non-certified)

Cl (μg/g) not analyzed 293 ± 31 354 ± 11 349 ± 29 360 ± 19

Co (μg/g) 0.109 ± 0.003 0.1 (non-certified) 0.071 ± 0.002 0.07 (non-certified)

Cr (μg/g) 2.52 ± 0.15 2.84 2.6 ± 0.2 1.33 ± 0.09 0.55 1 (non-certified)

Cs (μg/g) 0.118 ± 0.004 0.079 ± 0.003

Cu (μg/g) See 1570a below 2.8 3.0 ± 0.3 3.72 ± 0.20 3.6 3.7 ± 0.4

Fe (μg/g) 186 ± 6 190 200 ± 10 224 ± 6 220 218 ± 14

Hg (μg/g) 0.1415 0.15 ± 0.05 0.0336 0.031 ± 0.007

K (%) not analyzed 0.37 ± 0.04 0.37% ± 0.02% 2.49 ± 0.07 2.54 ± 0.11 2.43% ± 0.03%

Mg (%) 0.122 ± 0.029 0.442 ± 0.016 0.432% ± 0.008%

Mn (μg/g) 692 ± 21 675 ± 15 99 ± 4 98 ± 3

Na (μg/g) 40.1 ± 3.0 25.7 ± 10 24 ± 2

Ni (μg/g) not analyzed 3.5 (non-certified) 0.73 ± 0.09 0.69 ± 0.09

P (%) 0.110 ± 0.004 0.117 0.12% ± 0.02% 0.132 ± 0.002 0.147 0.137% ± 0.007%

Pb (μg/g) not analyzed 10.8 ± 0.5 0.87 ± 0.03 0.87 ± 0.03

Rb (μg/g) 11.7 ± 0.3 11.4 11.7 ± 0.1 20.0 ± 0.6 19.8 19.7 ± 1.2

Sc (μg/g) 0.040 ± 0.001 0.03 (non-certified) 0.044 ± 0.001 0.04 (non-certified)

Se (μg/g) 0.061 ± 0.027 0.117 ± 0.004 0.120 ± 0.009

Zn (μg/g) 65 ± 10 60.3 18.3 ± 1.3 18.7 17.9 ± 0.4

SRM 1570a

Element (units) Method 1 Certificate Values

Cu (μg/g) 12.5 ± 0.6 12.2 ± 0.6

Cd (μg/g) 2.86 ± 0.26 2.89 ± 0.07
14

Table 4. Average Mass Fraction Values Used to Provide Certificate Values for SRM 1575a Pine Needles.

Element Method 1 Method/Lab Method 2 Method/Lab Method 3 Method/Lab Certified Value

Al (μg/g) 575 ± 16 INAA/NIST 589 ± 29 ICPAES/USGS 580 ± 30

Ba (μg/g) 5.96 ± 0.45 INAA/NIST 6.06 ± 0.43 ICPMS/NIST 6.0 ± 0.2

Cd (μg/g) 0.233 ± 0.009 RNAA/NIST 0.234 ± 0.003 ICPMS/NIST 0.233 ± 0.004

Ca (%) 0.248 ± 0.007 INAA/NIST 0.250 ± 0.013 ICPMS/USGS 0.258 ± 0.012 ICPAES/USGS 0.25 ± 0.02

Cl (μg/g) 417 ± 3 PGAA/NIST 425 ± 8 INAA/NIST 421 ± 7

Cu (μg/g) 2.89 ± 0.03 RNAA/NIST 2.70 ± 0.17 ICPAES/USGS 2.8 ± 0.2

Fe (μg/g) 45.9 ± 0.5 INAA/NIST 46.0 ± 2.3 ICPAES/USGS 46 ± 2

K (%) 0.4137 ± 0.0037 PGAA/NIST 0.4209 ± 0.0128 INAA/NIST 0.417 ± 0.007

Hg (μg/g) 0.0399 ± 0.0004 CVIDMS/NIST 0.0414 ± 0.0028 RNAA/NIST 0.0399 ± 0.0007

P (%) 0.102 ± 0.002 RNAA/NIST 0.112 ± 0.005 ICPAES/USGS 0.107 ± 0.008

Rb (μg/g) 16.55 ± 0.14 INAA/NIST 16.36 ± 0.81 ICPMS/USGS 16.5 ± 0.9

Zn (μg/g) 38.0 ± 0.2 INAA/NIST 37.7 ± 1.8 ICPAES/USGS 38 ± 2

Reference Value

As (μg/g) 38.9 ± 1.2 INAA/NIST 0.039 ± 0.002

B (μg/g) 9.6 ± 0.2 PGAA/NIST

Cs (μg/g) 283 ± 3 INAA/NIST 0.283 ± 0.009

Co (μg/g) 61.4 ± 0.8 INAA/NIST 0.061 ± 0.002

Pb (μg/g) 0.167 ± 0.013 ICPMS/NIST 0.167 ± 0.015

Mg (%) 0.106 ± 0.007 INAA/NIST 0.106 ± 0.017

Mn (μg/g) 488 ± 6 INAA/NIST 488 ± 12

Ni (μg/g) 1.47 ± 0.10 ICPMS/NIST 1.47 ± 0.10

Sc (μg/g) 0.0101 ± 0.0002 INAA/NIST 0.0101 ± 0.0003

Se (μg/g) 0.099 ± 0.004 INAA/NIST 0.099 ± 0.004

Na (μg/g) 63 ± 2 INAA/NIST 63 ± 1

Information

Value

Cr (μg/g) 0.375 ± 0.065 INAA/NIST 0.32 ± 0.02 ICPAES/USGS 0.39 ± 0.03 ICPMS/USGS 0.3 - 0.5

Ce (μg/g) 0.114 ± 0.010 INAA/NIST 0.11
15

INTERLABORATORY COMPARISON METHODS

The ASTM Task Group for Nuclear Methods of Chemical Analysis has sponsored

interlaboratory comparison exercises for the last 20 y to provide laboratories with the

opportunity to assess their analytical capabilities. Fifteen laboratories participated in this

comparison exercise for analysis of inorganic constituents of SRM 1575a Pine Needles and one

additional laboratory submitted values for the isotopes 232Th and 238U. All participants were

provided one bottle containing about 6 g of SRM 1575a Pine Needles and another containing

about 6 g of SRM 1547 Peach Leaves for use as a control material. The instructions included a

request to the laboratories to analyze a minimum of three portions weighing at least 200 mg. 

Analysts were also instructed to determine the material dry mass using three separate portions

not used for elemental analysis and to report the results of analysis on a dry-mass basis. The list

of participants is included in Appendix C. 

When data were received, each lab was assigned (randomly) a number between 1 and 24 for

identification purposes. Labs that provided values from more than one analytical technique were

given alphabetical additions to the number codes, e.g., Laboratory 13a, 13b, and 13c, or

Laboratory 15a and 15b. These data were not combined into a single value from that one

laboratory, but rather were treated as if they were from separate laboratories. Most participants

used INAA to determine element content but a few laboratories provided additional information

using other techniques (e.g., RNAA, flame atomic absorption spectrometry [AAS], or graphite

furnace AAS) and one lab used ASTM methods. The analytical methods used by each

laboratory for each element are listed in Table 5 together with the laboratory number code. 

RESULTS OF THE ASTM INTERLABORATORY COMPARISON

The results from each laboratory are listed in Appendix D identified only by laboratory number

code and results for each element are listed in Appendix E. All data from the study participants

were compiled and average and standard deviation values were calculated where possible. Values

from individual laboratories were then compared with certificate values where available and with

the average value from all participants where no certificate value was available. These

comparisons were done in the form of z-scores that were calculated according to the following

equation:

5. z = (xn - xref)/(sxref)

where xn is the value for the participating laboratory, 10% was selected as the relative standard

deviation s, and xref is either the certificate value or the ASTM average (where no certificate

value was available). Outlier rejection was based on z-score values >+3 or <-3, indicating that the

reported value differed from the reference value by greater than 30%. After any outliers were

identified, the ASTM average was recalculated and the z-scores were re-evaluated so that the

final values listed reflect this iterative approach. Results that were rejected based on this criteria
16

have been shaded in the tables in Appendices D and E. Average and z-score values were not

calculated in cases where no certificate value was available and the number of values was ≤ 3. 

Average and z-scores were not calculated for either Hf or Au because the range of values was too

great, and therefore agreement too poor, to permit meaningful data analysis. Where no statistical

analyses were performed, cells in the tables have been filled with diagonal hatch marks.

Table 5. Methods Used by Participants in the ASTM Interlaboratory Comparison Exercise for

Determination of Element Content of SRM 1575a Pine Needles

Lab No. Elements Methods

2 232Th, 238U Radioisotope Analysis

3 Al, Sb, As, Ba, Br, Ca, Cd, Ce, Cs, Cl, Cr,

Co, Cu, F, Au, Hf, Fe, La, Mg, Mn, Hg,

K, Rb, Sm, Sc, Se, Na, Sr, Th, Zn

INAA

4 Br, Co, Eu, Fe, La, Rb, Sm, Sc, Se, Zn INAA

6 Sb, As, Ba, Br, Ca, Ce, Cs, Cl, Cr, Co, Fe,

La, Mg, Mn, K, Rb, Sm, Sc, Na, Th, Zn

INAA

8 Al, Sb, As, Ba, Br, Ca, Cs, Cl, Cr, Co, Eu,

Au, Fe, La, Mg, Mn, Ni, K, Rb, Sm, Sc,

Se, Sr, Ta, Th, U, V, Zn

INAA

10 Co, Mo, Rb, Sc, U, Zn INAA

13a As, Ba, Br, Cs, Cr, Co, Au, Hf, Fe, La,

Mn, P, K, Rb, Sc, Na, Th, Zn

INAA-1

RNAA (P only)

13b Sb, Ba, Br, Ce, Cs, Cr, Co, Hf, Fe, La, K,

Rb, Sm, Sc, Se, Th, Yb, Zn

INAA-2

13c Ca, Fe, Mg, Mn, K, Na, Zn AAS

15a Br, Mn, K, Na INAA

15b Al, Ca, Cd, Cr, Co, Cu, Fe, Pb, Mg, Mn,

Ni, K, Ag, Na, Zn

FAAS/GFAAS

16 Sb, Ba, Br, Ca, Cd, Ce, Cs, Cr, Co, Eu,

Au, Hf, Fe, La, Lu, Hg, Ni, K, Rb, Sm, Sc,

Se, Na, Sr, Ta, Tb, Th, Tb, Zn

INAA

17 Al, Sb, As, Br, Ca, Cs, Cl, Cr, Co, Fe, Mg,

Mn, K, Rb, Sc, Na, Zn

INAA

18 Br, Ca, Ce, Co, Fe, La, Nd, K, Rb, Sm, Sc,

Na, Tb, Zn

INAA

19 As, Ba, Cs, Cr, Co, Fe, La, K, Rb, Sc, Na,

Zn

INAA

20 Sb, As, Ba, Br, Ca, Ce, Cs, Cr, Co, Eu,

Au, Hf, Fe, La, Lu, Hg, K, Rb, Sm, Sc, Se,

Na, Sr, Ta, Tb, Th, Yb, Zn

INAA
17

21 Br, Ca, Cs, Co, Fe, K, Rb, Sc, Na, Zn INAA

23 Ca, Cu, Fe, Mg, Mn, Total Kjeldahl N, P,

K, S, Zn

E-6010

ASTM#1402-07 (TKN, P)

ASTM# 1552-90 (S)

24 Al, Sb, As, Br, Ca, Cl, La, Mg, Mn, Mo,

Ni, K, Sm, Na

INAA

A summary of the interlaboratory comparison data is presented in Table 6 together with the

certified values. Note that the number of values for each element differed greatly, ranging from 16

values to just one value. Because outlier rejection was based on comparison with the certificate

values, the interlaboratory averages calculated after rejection of outliers generally agree better

with the certificate values. In all cases, standard deviation values were reduced by outlier

rejection. Participants also provided mass fraction values or limits of detection for 23 elements

(Au, Br, Eu, F, Ga, Hf, I, In, Ir, La, Mo, total Kjeldahl N, S, Sb, Sm, Sr, Ta, Tb, Th, W, U, and

Yb) that were not included on the certificate of analysis for SRM 1575a. A summary of these

results is shown in Table 7. The number of values for these elements is generally smaller but

ranged from 13 values for Br to a single value for the following eight elements: F, Ga, In, I, Ir,

Total Kjeldahl N, S, W. The average values before and after outlier rejection were calculated

except in cases where there was only one value, or in cases where agreement among the values

was too poor to permit meaningful data analysis. 

Nota Bene: Results of analyses from this ASTM interlaboratory comparison exercise are

included in this report to provide a complete description of the study results. Any values

in this report that are not included on the Certificate of Analysis have not been evaluated

for accuracy and should not be used as certificate values. 
18

Table 6. Results of the ASTM Interlaboratory Comparison Exercise for Determination of

Element Content of SRM 1575a Pine Needles Compared with Certificate Mass Fraction Values.

Element (unit) Certificate Mass

Fraction Value

Interlaboratory

Average ± 1s

n

Interlaboratory

(after outlier

rejection)

Average ± 1s

n

Aluminum (μg/g) 580 ± 30 583 ± 128 5 533 ± 69 4

Barium (μg/g) 6.0 ± 0.2 6.2 ± 1.9 8 5.4 ± 0.4 5

Cadmium (μg/g) 0.233 ± 0.004 0.208 ± 0.178 3 0.252 1

Calcium (%) 0.25 ± 0.02 0.253 ± 0.072 12 0.24 ± 0.02 10

Chlorine (μg/g) 421 ± 7 399 ± 22 5 399 ± 22 5

Copper (μg/g) 2.8 ± 0.2 2.9 ± 1.0 3 3.0 1

Iron (μg/g) 46 ± 2 56 ± 42 14 46 ± 3 12

Potassium (%) 0.417 ± 0.007 0.421 ± 0.529 13 0.407 ± 0.016 12

Mercury (μg/g) 0.0399 ± 0.0007 0.024 ± 0.018 3 0.0341 ± 0.0071 2

Phosphorus (%) 0.107 ± 0.008 0.118 ± 0.008 2 0.118 ± 0.008 2

Rubidium (μg/g) 16.5 ± 0.9 15.1 ± 4.8 12 16.5 ± 0.7 11

Zinc (μg/g) 38 ± 2 37 ± 5 14 36 ± 4 13

Element (unit)

Reference Mass

Fraction Value

Interlaboratory

Average ± 1s

n Interlaboratory

(after outlier

rejection)

Average ± 1s

n

Arsenic (μg/g) 0.039 ± 0.002 0.048 ± 0.023 8 0.040 ± 0.005 7

Cesium (μg/g) 0.283 ± 0.009 0.276 ± 0.029 10 0.284 ± 0.012 9

Cobalt (μg/g) 0.061 ± 0.002 0.101 ± 0.132 12 0.063 ± 0.007 11

Lead (μg/g) 0.167 ± 0.015 0.115 ± 0.031 1 no values 0

Magnesium (%) 0.106 ± 0.017 0.100 ± 0.018 8 0.105 ± 0.010 7

Manganese (μg/g) 488 ± 12 458 ± 31 8 458 ± 31 8

Nickel (μg/g) 1.47 ± 0.10 1.21 ± 0.27 4 1.31 ± 0.22 3

Scandium (μg/g) 0.0101 ± 0.0003 0.018 ± 0.025 12 0.0104 ± 0.0015 11

Selenium (μg/g) 0.099 ± 0.004 0.093 ± 0.044 6 0.118 ± 0.015 4

Sodium (μg/g) 63 ± 1 71 ± 20 11 63 ± 5 9

Element (unit) Information Values

Interlaboratory

Average ± 1s

n Interlaboratory

(after rejection of

selected data )

Average ± 1s

n

Chromium (μg/g) 0.3 - 0.5 0.502 ± 0.507 10 0.334 ± 0.039 8

Cerium (μg/g) 0.11 0.208 ± 0.261 6 0.10 ± 0.02 5
19

Table 7. Results of the ASTM Interlaboratory Comparison Exercise for Determination of

Element Content of SRM 1575a Pine Needles: elements not included on the Certificate of

Analysis.

Element (units) Range

Interlaboratory

Average ± 1s

or single value

n*

Range (after

outlier rejection)

Interlaboratory (after

outlier rejection)

Average ± 1s

n

Antimony (mg/kg) 0.0062 - 0.033 0.015 ± 0.009 8 0.0062 - 0.0099 0.009 ± 0.001 4

Bromine(mg/kg) 2.10 - 3.91 2.95 ± 0.42 13 2.10 - 3.38 2.87 ± 0.32 12

Europium(mg/kg) <0.002 - 0.0017

(n = 5)

0.0014 ±

0.0003

3

Fluorine(mg/kg) 389 1

Gallium(mg/kg) <1 1

Gold (mg/kg) 0.00026- 0.0026 5

Hafnium(mg/kg) <0.015 - 0.12 5

Indium(mg/kg) <0.003 1

Iodine(mg/kg) <1.5 1

Iridium(mg/kg) <0.0001 1

Lanthanum(mg/kg) 0.042 - 0.39 0.101 ± 0.106 10 0.042 - 0.066 0.053 ± 0.008 8

Molybdenum

(mg/kg)

<0.1 - 0.0124

(n = 3)

0.0124 1

Neodymium

(mg/kg)

0.0283 1

Nitrogen (TKN)% 1.11 1

Samarium(mg/kg) 0.0059 - 0.042 0.012 ± 0.011 9 0.0059 - 0.0090 0.0077 ± 0.0009 8

Strontium(mg/kg) 4.9 - 8.5 6.8 ± 1.5 4 no data rejected no data rejected 4

Sulfur(%) 0.102 1

Tantalum (mg/kg) 0.0011 - 0.0028,

<0.005 (n = 1)

0.0018 ±

0.0009

3

Terbium(mg/kg) 0.00053, 0.008 2

Thorium(mg/kg) 0.010 - 0.205 0.068 ± 0.090 7 0.014 - 0.018 0.016 ± 0.001 4

232Th (mg/kg) 0.027 1

Tungsten(mg/kg) 0.065 1

Uranium (mg/kg) 0.007 - 0.012

(<0.04, <0.08)

0.087 ± 0.003 3

238U (mg/kg) 0.0049 1

Vanadium (mg/kg) <0.08 - <0.34 3

Ytterbium (mg/kg) 0.002 - 0.025 3

*The values included in the average do not include values that were reported as limits of

detection. The value for "n" represents the number of laboratories, not number of portions

analyzed.
20

Nota Bene: Results of analyses from this ASTM interlaboratory comparison exercise are

included in this report to provide a complete description of the study results. Any values

in this report that are not included on the Certificate of Analysis have not been evaluated

for accuracy and should not be used as certificate values. 
21

References

Christopher SJ, Long SE, Rearick MS, Fassett JD. Anal. Chem. 73, 2190-2199, 2001

Greenberg RR. Anal. Chem. 58, 2516-2523, 1986.

Levenson MS, Banks DL, Eberhardt KR, Gill LM, Guthrie WF, Liu HK, Vangel MS, Yen

JH, Zhang NF, J Res. NIST 105(2000) 571-579.

Long SE, Kelly WR, Anal. Chem. 74, 1477-1483, 2002.

May W, Parris R, Beck C, Fassett J, Greenberg R, Guenther F, Kramer G, Wise S, Gills T,

Colbert J, Gettings R, MacDonald B. NIST SP 230-136 “Definitions of Terms and Modes

Used at NIST for Value-Assignment of Reference Materials for Chemical Measurements”

U.S. Government Printing Office Washington, pp. 12, 2000.

U.S. Geological Survey Open File Report 02-0223-G Analytical Methods for Chemical

Analysis of Geological and Other Materials U.S. Geological Survey. Chapter I “The

Determination of 40 Elements in Geological Materials by Inductively Coupled PlasmaAtomic Emission Spectrometry.” PH Briggs, pp. 18, 2002.

U.S. Geological Survey Open File Report 02-0223-I, Analytical Methods for Chemical

Analysis of Geological and Other Materials U.S. Geological Survey, Chapter I “The

Determination of 42 Elements in Geological Materials by Inductively Coupled Plasma-Mass

Spectrometry.” PH Briggs and AL Meier, pp. 14, 2002.
22

Appendix A Results of Certification Analyses of Individual Portions of SRM 1575a

Performed at NIST and at USGS Presented by Technique and Laboratory
23

NIST-CVIDMS NIST-ICPMS

Bottle No. Hg (ng/g) Ba (μg/g) Pb (μg/g) Ni (μg/g) Cd (μg/g)

83 5.78 0.157 1.478 0.235

189 40.35 5.82 0.156 1.539 0.232

356 40.21 6.84 0.189 1.500 0.233

472 40.11 5.79 0.161 1.430 0.240

708 39.46 5.82 0.164 1.587 0.233

1107 39.52 6.29 0.173 1.313 0.232

average 39.9 6.06 0.167 1.475 0.234

std dev 0.4 0.43 0.013 0.095 0.003

n 5 6 6 6 6

NIST-RNAA

Bottle No. P (%) RNAA

66 0.101 Bottle No Cu (μg/g) Cd (ng/g)

522 0.101 66 2.93 231

606 0.103 227 2.86 229

739 0.100 308 2.89 226

803 0.102 739 2.90 245

865 0.103 803 2.89 223

953 0.104 986 2.92 237

986 0.106 1027 2.88 247

1027 0.102 1142 2.86 232

1224 0.101 1333 224

average 0.102 average 2.89 233

std dev 0.002 std dev 0.03 9

n 10 n 8 9

NIST-PGAA

Bottle No. B (μg/g) Cl (μg/g) K (μg/g)

66 9.66 410 4153

227 9.60 414 4127

308 9.44 417 4107

522 9.62 424 4206

739 9.62 416 4108

953 9.63 414 4108

986 9.63 418 4173

1027 9.55 424 4115

average 9.59 417 4137

std dev 0.07 5 37

n 8 8 8
24

NIST-INAA

Bottle No. As (ng/g) Ba (μg/g) Co (ng/g) Cr (ng/g) Cs (ng/g) Fe (μg/g) Zn μg/g)

1333 38.8 6.7 62.0 460 285 46.4 38.1

739 37.6 6.0 61.1 340 280 46 37.9

522 40.8 5.9 60.3 358 283 46.2 38.1

308 39.5 5.4 61.7 359 283 46.5 38.2

66 36.8 6.3 62.5 354 281 45.4 37.5

1142 38.8 5.6 60.6 349 283 46.1 38.0

953 -- 5.4 61.9 524 281 45.4 37.8

606 39.5 6.5 62.0 326 287 45.4 38.3

308 -- 5.7 60.6 355 284 45.3 38.1

227 39.3 6.1 60.8 323 278 45.8 37.9

average 38.9 5.96 61.4 374.8 283 45.9 38.0

std dev 1.2 0.45 0.8 64.8 3 0.5 0.2

n 8 10 10 10 10 10 10

NIST INAA

Bottle No. Ce (ng/g) Rb (μg/g) Sb (ng/g) Sc (ng/g) Se (ng/g) Th (ng/g)

1333 110.0 16.7 7.2 10.3 105 17.1

739 104.0 16.5 7.2 9.87 104 17.3

522 103.0 16.7 7.2 10.0 101 14.9

308 107.0 16.6 7.0 10.3 101 15.7

66 122.0 16.4 6.3 9.87 95 14.2

1142 108.0 16.7 7.1 10.1 95 16.5

953 114.0 16.4 7.3 10.1 95 16.3

606 116.0 16.7 7.9 10.0 98 15.4

308 124.0 16.4 7.0 10.1 96 17.6

227 132.0 16.4 6.8 10.0 99 19.7

average 114.0 16.6 7.1 10.1 99 16.5

std dev 9.5 0.1 0.4 0.2 4 1.6

n 10 10 10 10 10 10
25

NIST-INAA short-lived

Bottle No. Na μg/g K μg/g Mn μg/g Cl μg/g Al μg/g Mg μg/g Ca %

1027 61.1 4340 490 429 562 1011 0.253

1027 62.3 4190 485 440 0.271

1142 62.4 4210 488 425 562 1031 0.254

1142 60.2 3840 463 430 564 1072 0.240

133 64.5 4000 489 436 560 0.246

133 61.1 4380 486 432 587 976 0.244

227 64.1 4260 491 420 564 1057 0.247

227 63.2 4170 489 414 581 1195 0.247

260 67.2 4010 490 428 557 909 0.241

260 63.8 4160 489 415 586 1019 0.248

29 62.1 4320 491 417 561 979 0.243

29 63.7 4210 488 432 591 1108 0.245

308 61.5 4340 491 428 584 980 0.251

308 61.7 4240 488 429 608 1050 0.242

522 62.4 4330 491 428 564 1063 0.251

52 64.6 4340 493 420 614 1193 0.256

739 64.4 4290 491 424 561 1114 0.257

739 63.4 4330 487 420 573 1154 0.245

803 61.7 4230 488 429 568 1035 0.255

803 61.2 4170 487 426 593 1015 0.248

953 61.7 4220 491 416 565 1158 0.236

953 64.1 4160 486 407 575 1062 0.240

986 62.1 4190 491 425 571 1006 0.242

986 60.4 4080 485 422 585 1080 0.251

average 62.7 4209 488 425 575 1058 0.248

std dev 1.6 128 6 8 16 73 0.007

n 24 24 24 24 23 22 24

NIST RNAA

Bottle No. Hg (ng/g)

29 37.61

66 43.53

308 45.18

522 43.13

606 39.61

1142 42.61

1224 39.01

average 41.5

std dev 2.8

n 7
26

USGS ICP40 ICP40 ICPMS_ACID ICP40 ICP40 ICP40 ICPMS_ACID ICP40

Bottle No. Al Ca Ca Cu Fe P Rb Zn

mg/kg % % mg/kg mg/kg % mg/kg mg/kg

766a 630 0.27499 0.221 2.72 48.8 0.115 14.7 40.1

901a 590 0.26378 0.237 2.69 46.2 0.112 15.4 37.8

1191a 625 0.27178 0.264 2.84 48.5 0.118 17.2 39.4

1255b 600 0.26001 0.247 2.60 46.4 0.111 16.2 37.4

491a 605 0.27216 0.244 2.67 47.1 0.114 15.9 38.8

1255a 593 0.25272 0.247 2.92 46.4 0.115 16.1 38.4

1149a 539 0.23976 0.249 2.49 42.2 0.103 16.3 34.6

824b 578 0.25546 0.263 2.63 45.8 0.111 17.2 37.4

619b 571 0.2491 0.26 2.63 44.4 0.109 16.9 36.2

491b 607 0.2646 0.247 2.67 47.4 0.114 16.2 38.6

824a 569 0.2444 0.264 2.70 42.5 0.109 17.3 36.9

619a 578 0.25064 0.259 2.68 45.3 0.111 17.1 37.1

1191b 612 0.26924 0.267 2.79 48.3 0.117 17.5 39.1

1149b 528 0.2331 0.251 2.38 41.7 0.101 16.5 34.0

766b 622 0.26728 0.23 3.14 49.1 0.122 15.2 40.3

901b 576 0.25168 0.245 2.61 46.0 0.110 16.1 37.0

Avg 589 0.258 0.250 2.70 46.0 0.112 16.36 37.7

Std Dev 29 0.012 0.013 0.17 2.3 0.005 0.82 1.8

n 16 16 16 16 16 16 16 16
27

Appendix B Copy of the SRM1575a Pine Needles Certificate of Analysis
28
29
30
31
32
33

Appendix C. List of Participants in ASTM Interlaboratory Comparison Exercise

Participant/Analyst(s) Affiliation City, Country

Ljudmila Benedik,

Urska Repinc

Dept. of Environmental Sciences

Jozef Stefan Institute

Ljubljana, Slovenia

Maria Carmo-Fritas Instituto Tecnológico E Nuclear Sacavem, Portugal

Sara Resnizky Comisión Nacional de Energía

Atómica

Buenos Aires, Argentina

Elisabete Fernandes,

Cláudio Luiz Gonzaga

CENA, Laboratorio de Radioisotopos,

University of Sao Paulo

Sao Paulo, Brazil

Craig Stuart Becquerel Laboratories Mississauga, Ontario, Canada

Gregory Kennedy, 

Jean St-Pierre

Écolé Polytechnique Montréal

Slowpoke Laboratory

Centre-Ville, Montréal, Canada

Jan Kucera Czech Academy of Sciences Rez near Prague, Czech Republic

M. Sundersanan, 

S. R. Kayatsth,

K. K. Swain

Government of India,

Bhabha Atomic Research Centre,

Analytical Chemistry Division

Trombay, Mumbai, India

E. Wallich,

Maxine Ranta

Weyerhaeuser Analytical and Testing

Services

Federal Way, Washington, USA

Raymund Gwozdz TraceChem Copenhagen, Denmark

Achim Berger,

 Wolf Goerner

Lab 1.43, Activation Analysis

BAM

Berlin, Germany

Marina Frontasyeva Joint Institute for Nuclear Research Dubna, Russia

Bozena Danko Institute for Nuclear Research Warsaw, Poland

Amarnath Garg,

Ashok Kumar

Radioanalytical Laboratory

Department of Chemistry

Indian Institute of Technology

Roorkee, India

Xileio Lin

Richard Henkelmann

Technical University of Munich Munich, Germany

Sophie Ayrault Laboratory Pierre Sue,

Commissariat á l'Energie Atomique,

CNRS

Saclay, France
34

Appendix D Analytical Results From Each Participant in the ASTM Interlaboratory

Comparison Coded by Participant Numbers
35

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 3 580 19 2 0.0 INAA

Antimony (mg/kg) Lab 3 0.0120 0.001 1 3.3 INAA

Arsenic (mg/kg) Lab 3 0.047 0.009 2 2.1 INAA

Barium (mg/kg) Lab 3 5.2 1 2 -1.3 INAA

Bromine (mg/kg) Lab 3 3.16 0.1 2 1.0 INAA

Cadmium (mg/kg) Lab 3 0.252 0.014 2 0.8 INAA

Calcium (%) Lab 3 0.252% 0.014% 2 0.0 INAA

Cerium (mg/kg) Lab 3 0.114 0.017 2 0.4 INAA

Cesium (mg/kg) Lab 3 0.30 0.01 2 0.6 INAA

Chlorine (mg/kg) Lab 3 389 17 2 -0.8 INAA

Chromium (mg/kg) Lab 3 0.36 0.03 2 0.8 INAA

Cobalt (mg/kg) Lab 3 0.074 0.003 2 2.1 INAA

Copper (mg/kg) Lab 3 3.9 0.6 2 3.9 INAA

Fluorine (mg/kg) Lab 3 389 20 2 INAA

Gallium (mg/kg) Lab 3 <1 2 INAA

Gold (mg/kg) Lab 3 0.00056 0.00018 2 INAA

Hafnium (mg/kg) Lab 3 0.014 0.02 2 INAA

Indium (mg/kg) Lab 3 <0.003 2 INAA

Iodine (mg/kg) Lab 3 <1.5 2 INAA

Iridium (mg/kg) Lab 3 <0.0001 2 INAA

Iron (mg/kg) Lab 3 51.4 2.2 2 1.2 INAA

Lanthanum (mg/kg) Lab 3 0.0565 0.0050 2 0.6 INAA

Magnesium (%) Lab 3 0.109% 0.012% 2 0.3 INAA

Manganese (mg/kg) Lab 3 502 16 2 0.3 INAA

Mercury (mg/kg) Lab 3 0.029 0.007 2 -0.2 INAA

Molybdenum (mg/kg) Lab 3 <0.1 2 INAA

Nickel (mg/kg) Lab 3 <1.3 2 INAA

Potassium (%) Lab 3 0.404% 0.015% 2 -0.3 INAA

Rubidium (mg/kg) Lab 3 16.4 0.5 2 -0.1 INAA

Samarium (mg/kg) Lab 3 0.0078 0.0004 2 0.1 INAA

Scandium (mg/kg) Lab 3 0.0116 0.0005 2 1.5 INAA

Selenium (mg/kg) Lab 3 0.13 0.02 2 3.1 INAA

Silver (mg/kg) Lab 3 <0.03 2 INAA

Sodium (mg/kg) Lab 3 63.0 2.4 2 0.0 INAA

Strontium (mg/kg) Lab 3 7.2 1.3 2 0.5 INAA

Tantalum (mg/kg) Lab 3 <0.005 1 INAA

Thorium (mg/kg) Lab 3 0.016 0.002 2 0.0 INAA

Uranium (mg/kg) Lab 3 <0.04 1 INAA

Vanadium (mg/kg) Lab 3 <0.26 2 INAA

Zinc (mg/kg) Lab 3 38.5 2.0 2 0.1 INAA
36

Element Lab No. Average 1s n z-score Method

Bromine (mg/kg) Lab 4 2.966 0.248 6 0.4 INAA

Cobalt (mg/kg) Lab 4 0.0686 0.0064 6 1.2 INAA

Europium (mg/kg) Lab 4 0.0017 0.0006 6 INAA

Iron (mg/kg) Lab 4 50.0 5.6 6 0.9 INAA

Lanthanum (mg/kg) Lab 4 0.0565 0.0057 6 0.6 INAA

Rubidium (mg/kg) Lab 4 15.8 2.8 6 -0.4 INAA

Samarium (mg/kg) Lab 4 0.0080 0.00071 6 0.3 INAA

Scandium (mg/kg) Lab 4 0.0106 0.0008 6 0.5 INAA

Selenium (mg/kg) Lab 4 0.113 0.010 6 1.4 INAA

Zinc (mg/kg) Lab 4 40.2 2.5 6 0.6 INAA
37

Element Lab No. Average 1s n z-score Method

Antimony (mg/kg) Lab 6 0.0099 0.0035 4 1.0 INAA

Arsenic (mg/kg) Lab 6 0.037 0.008 4 -0.5 INAA

Barium (mg/kg) Lab 6 5.7 2.3 4 -0.5 INAA

Bromine (mg/kg) Lab 6 2.84 0.07 4 -0.1 INAA

Calcium (%) Lab 6 0.240% 0.024% 4 -0.4 INAA

Cerium (mg/kg) Lab 6 0.119 0.028 4 0.8 INAA

Cesium (mg/kg) Lab 6 0.286 0.012 4 0.1 INAA

Chlorine (mg/kg) Lab 6 396 21 4 -0.6 INAA

Chromium (mg/kg) Lab 6 0.290 0.051 4 -1.3 INAA

Cobalt (mg/kg) Lab 6 0.060 0.005 4 -0.2 INAA

Europium (mg/kg) Lab 6 <0.002 4 INAA

Iron (mg/kg) Lab 6 43.3 3.0 4 -0.6 INAA

Lanthanum (mg/kg) Lab 6 0.066 0.012 4 2.4 INAA

Magnesium (%) Lab 6 0.096% 0.018% 4 -1.0 INAA

Manganese (mg/kg) Lab 6 475.1 6.4 4 -0.3 INAA

Potassium (%) Lab 6 0.3971% 0.0081% 4 -0.5 INAA

Rubidium (mg/kg) Lab 6 17.1 0.5 4 0.4 INAA

Samarium (mg/kg) Lab 6 0.0080 0.0016 4 0.4 INAA

Scandium (mg/kg) Lab 6 0.0097 0.0005 4 -0.4 INAA

Sodium (mg/kg) Lab 6 56.1 1.0 4 -1.1 INAA

Thorium (mg/kg) Lab 6 0.0178 0.0055 4 1.1 INAA

Zinc (mg/kg) Lab 6 37.6 1.0 4 -0.1 INAA
38

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 8 553 55 6 -0.5 INAA

Antimony (mg/kg) Lab 8 0.0083 0.0012 6 -0.8 INAA

Arsenic (mg/kg) Lab 8 0.037 0.006 6 -0.5 INAA

Barium (mg/kg) Lab 8 5.9 0.6 6 -0.2 INAA

Bromine (mg/kg) Lab 8 3.1 0.3 6 0.8 INAA

Calcium (%) Lab 8 0.243% 0.036% 6 -0.3 INAA

Cerium (mg/kg) Lab 8 <0.16 6 INAA

Cesium (mg/kg) Lab 8 0.30 0.03 6 0.6 INAA

Chlorine (mg/kg) Lab 8 438 44 6 0.4 INAA

Chromium (mg/kg) Lab 8 0.33 0.1 6 -0.1 INAA

Cobalt (mg/kg) Lab 8 0.067 0.010 6 1.0 INAA

Europium (mg/kg) Lab 8 <0.03 6 INAA

Gold (mg/kg) Lab 8 0.00260 0.0005 6 INAA

Hafnium (mg/kg) Lab 8 <0.015 6 INAA

Iron (mg/kg) Lab 8 48 6 6 0.4 INAA

Lanthanum (mg/kg) Lab 8 0.058 0.009 6 0.9 INAA

Magnesium (%) Lab 8 0.102% 0.017% 6 -0.3 INAA

Manganese (mg/kg) Lab 8 465 46 6 -0.5 INAA

Nickel (mg/kg) Lab 8 1.29 0.19 6 -1.2 INAA

Potassium (%) Lab 8 0.426% 0.085% 6 0.2 INAA

Rubidium (mg/kg) Lab 8 18.1 1.8 6 1.0 INAA

Samarium (mg/kg) Lab 8 0.0082 0.0008 6 0.6 INAA

Scandium (mg/kg) Lab 8 0.0126 0.0025 6 2.5 INAA

Selenium (mg/kg) Lab 8 0.13 0.03 6 3.1 INAA

Strontium (mg/kg) Lab 8 8.5 0.8 6 2.4 INAA

Tantalum (mg/kg) Lab 8 0.0028 0.0007 6 INAA

Thorium (mg/kg) Lab 8 0.016 0.002 6 0.0 INAA

Tungsten Lab 8 0.065 0.019 6 INAA

Uranium (mg/kg) Lab 8 0.0068 0.0014 6 INAA

Vanadium (mg/kg) Lab 8 <0.27 6 INAA

Zinc (mg/kg) Lab 8 38.2 3.8 6 0.1 INAA
39

Element Lab No. Average 1s n z-score Method

Cobalt (mg/kg) Lab 10 0.0598 0.0048 3 -0.2 INAA

Molybdenum (mg/kg) Lab 10 0.0124 0.0012 4 INAA

Rubidium (mg/kg) Lab 10 16.18 1.62 3 -0.2 INAA

Scandium (mg/kg) Lab 10 0.0117 0.0009 3 1.6 INAA

Uranium (mg/kg) Lab 10 0.0071 0.0011 4 INAA

Zinc (mg/kg) Lab 10 39.3 2.0 3 0.3 INAA
40

Element Lab No. Average 1s n z-score Method

Arsenic (mg/kg) Lab 13a 0.104 0.019 2 16.7 INAA

Barium (mg/kg) Lab 13a 9.5 1.7 3 5.8 INAA

Bromine (mg/kg) Lab 13a 3.08 0.16 5 0.7 INAA

Cesium (mg/kg) Lab 13a 0.270 0.017 3 -0.5 INAA

Chromium (mg/kg) Lab 13a 1.33 0.33 6 29.9 INAA

Cobalt (mg/kg) Lab 13a 0.501 0.117 3 72.1 INAA

Gold (mg/kg) Lab 13a 0.00150 0.0004 3 INAA

Hafnium (mg/kg) Lab 13a 0.116 0.026 3 INAA

Iron (mg/kg) Lab 13a 192 19 6 32 INAA

Lanthanum (mg/kg) Lab 13a 0.335 0.022 3 53.0 INAA

Manganese (mg/kg) Lab 13a 506 47 4 0.4 INAA

Phosphorus (%) Lab 13a 0.112% 0.009% 10 0.5 INAA

Potassium (%) Lab 13a 0.431% 0.048% 7 0.3 INAA

Rubidium (mg/kg) Lab 13a 16.4 0.5 3 -0.1 INAA

Scandium (mg/kg) Lab 13a 0.097 0.012 3 86.0 INAA

Sodium (mg/kg) Lab 13a 111 36 7 7.6 INAA

Thorium (mg/kg) Lab 13a 0.205 0.032 3 118 INAA

Zinc (mg/kg) Lab 13a 51.5 2.9 3 3.6 INAA
41

Element Lab No. Average 1s n z-score Method

Antimony (mg/kg) Lab 13b 0.0330 0.007 3 26.7 INAA

Barium (mg/kg) Lab 13b 8.8 2.4 3 4.7 INAA

Bromine (mg/kg) Lab 13b 3.91 0.43 3 3.6 INAA

Cerium (mg/kg) Lab 13b 0.74 0.10 3 57.3 INAA

Cesium (mg/kg) Lab 13b 0.293 0.023 3 0.4 INAA

Chromium (mg/kg) Lab 13b 2.37 0.2 3 61.0 INAA

Cobalt (mg/kg) Lab 13b 0.541 0.130 3 78.7 INAA

Hafnium (mg/kg) Lab 13b 0.122 0.025 3 INAA

Iron (mg/kg) Lab 13b 208 19 3 35 INAA

Lanthanum (mg/kg) Lab 13b 0.389 0.03 3 63.1 INAA

Potassium (%) Lab 13b 0.467% 0.096% 3 1.2 INAA

Rubidium (mg/kg) Lab 13b 17.2 1.3 3 0.4 INAA

Samarium (mg/kg) Lab 13b 0.0420 0.003 3 44.5 INAA

Scandium (mg/kg) Lab 13b 0.098 0.009 3 87.0 INAA

Selenium (mg/kg) Lab 13b 0.017 0.002 3 -8.3 INAA

Thorium (mg/kg) Lab 13b 0.195 0.029 3 112 INAA

Ytterbium (mg/kg) Lab 13b 0.025 0.005 3 INAA

Zinc (mg/kg) Lab 13b 50.4 7.0 3 3.3 INAA

Element Lab No. Average 1s n z-score Method

Calcium (%) Lab 13c 0.457% 1 8.2 AAS

Iron (mg/kg) Lab 13c 49.9 1 0.8 AAS

Magnesium (%) Lab 13c 0.110% 0.4 AAS

Manganese (mg/kg) Lab 13c 309 -3.7 AAS

Potassium (%) Lab 13c 0.289% -3.1 AAS

Sodium (mg/kg) Lab 13c 133 11.1 AAS

Zinc (mg/kg) Lab 13c 49.9 3.1 AAS
42

Element Lab No. Average 1s n z-score Method

Bromine (mg/kg) Lab 15a 3.38 0.16 1 1.8 AAS

Manganese (mg/kg) Lab 15a 452 13 1 -0.7 AAS

Potassium (%) Lab 15a 0.398% 0.078% 1 -0.5 AAS

Sodium (mg/kg) Lab 15a 73.2 5.5 1 1.6 AAS

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 15b 786 67 4 3.6 FAAS/GFAAS

Cadmium (mg/kg) Lab 15b 0.360 0.040 2 5.5 FAAS/GFAAS

Calcium (%) Lab 15b 0.194% 0.029% 4 -2.3 FAAS/GFAAS

Chromium (mg/kg) Lab 15b 0.32 0.06 2 -0.4 FAAS/GFAAS

Cobalt (mg/kg) Lab 15b <0.035 1 FAAS/GFAAS

Copper (mg/kg) Lab 15b 1.86 0.18 2 -3.4 FAAS/GFAAS

Iron (mg/kg) Lab 15b 43.5 5.6 4 -0.5 FAAS/GFAAS

Lead (mg/kg) Lab 15b 0.115 0.031 4 -3.1 FAAS/GFAAS

Magnesium (%) Lab 15b 0.123% 0.009% 4 1.6 FAAS/GFAAS

Manganese (mg/kg) Lab 15b 405 40 4 -1.7 FAAS/GFAAS

Nickel (mg/kg) Lab 15b 1.10 0.04 2 -2.5 FAAS/GFAAS

Potassium (%) Lab 15b 0.44% 0.02% 4 0.6 FAAS/GFAAS

Silver (mg/kg) Lab 15b <0.05 1 FAAS/GFAAS

Sodium (mg/kg) Lab 15b 52.6 5.0 4 -1.7 FAAS/GFAAS

Zinc (mg/kg) Lab 15b 29.9 3 4 -2.1 FAAS/GFAAS
43

Element Lab No. Average 1s n z-score Method

Antimony (mg/kg) Lab 16 0.0062 0.0012 11 -3.1 INAA

Barium (mg/kg) Lab 16 4.0 0.3 8 -3.3 INAA

Bromine (mg/kg) Lab 16 2.1 0.4 8 -2.7 INAA

Cadmium (mg/kg) Lab 16 0.0119 0.0025 5 -9.5 INAA

Calcium (%) Lab 16 0.15% 0.01% 10 -4.0 INAA

Cerium (mg/kg) Lab 16 0.0783 0.0015 7 -2.9 INAA

Cesium (mg/kg) Lab 16 0.1991 0.0096 8 -3.0 INAA

Chromium (mg/kg) Lab 16 0.268 0.006 9 -2.0 INAA

Cobalt (mg/kg) Lab 16 0.0452 0.0028 8 -2.6 INAA

Europium (mg/kg) Lab 16 0.0011 0.0002 5 INAA

Gold (mg/kg) Lab 16 0.00070 0.0001 9 INAA

Hafnium (mg/kg) Lab 16 0.0063 0.0007 7 INAA

Iron (mg/kg) Lab 16 32.4 0.1 3 -3.0 INAA

Lanthanum (mg/kg) Lab 16 0.0416 0.0049 8 -2.2 INAA

Lutecium (mg/kg) Lab 16 0.0006 0.0001 7 INAA

Mercury (mg/kg) Lab 16 0.0035 0.0003 6 -9.1 INAA

Neodymium (mg/kg) Lab 16 0.0283 2 INAA

Nickel (mg/kg) Lab 16 0.9 0.1 6 -3.9 INAA

Potassium (%) Lab 16 0.59% 0.17% 3 4.1 INAA

Rubidium (mg/kg) Lab 16 0.0115 0.0004 8 -10.0 INAA

Samarium (mg/kg) Lab 16 0.0059 0.0008 9 -2.3 INAA

Scandium (mg/kg) Lab 16 0.0074 0.0001 7 -2.7 INAA

Selenium (mg/kg) Lab 16 0.0696 0.0066 8 -3.0 INAA

Silver (mg/kg) Lab 16 0.0118 2 INAA

Sodium (mg/kg) Lab 16 72.5 9.3 4 1.5 INAA

Strontium (mg/kg) Lab 16 4.9 0.7 4 -2.8 INAA

Tantalum (mg/kg) Lab 16 0.0011 0.0001 5 INAA

Terbium (mg/kg) Lab 16 0.0008 0.0001 4 INAA

Thorium (mg/kg) Lab 16 0.010 0.0002 7 -3.8 INAA

Uranium (mg/kg) Lab 16 0.0122 2 INAA

Ytterbium (mg/kg) Lab 16 0.0033 0.0007 6 INAA

Zinc (mg/kg) Lab 16 27.3 0.3 9 -2.8 INAA
44

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 17 567 20 3 -0.2 INAA

Antimony (mg/kg) Lab 17 0.0230 0.002 3 15.6 INAA

Arsenic (mg/kg) Lab 17 0.038 0.002 3 -0.3 INAA

Bromine (mg/kg) Lab 17 2.7 0.1 3 -0.6 INAA

Calcium (%) Lab 17 0.254% 0.013% 3 0.1 INAA

Cesium (mg/kg) Lab 17 0.28 0.01 3 -0.1 INAA

Chlorine (mg/kg) Lab 17 391 15 3 -0.7 INAA

Chromium (mg/kg) Lab 17 0.37 0.02 3 1.1 INAA

Cobalt (mg/kg) Lab 17 0.062 0.003 3 0.2 INAA

Iron (mg/kg) Lab 17 45 3 3 -0.2 INAA

Magnesium (%) Lab 17 0.096% 0.003% 3 -0.9 INAA

Manganese (mg/kg) Lab 17 474 15 3 -0.3 INAA

Potassium (%) Lab 17 0.408% 0.015% 3 -0.2 INAA

Rubidium (mg/kg) Lab 17 16.2 0.05 3 -0.2 INAA

Scandium (mg/kg) Lab 17 0.0108 0.0004 3 0.7 INAA

Sodium (mg/kg) Lab 17 67 3 3 0.6 INAA

Zinc (mg/kg) Lab 17 38.3 2.0 3 0.1 INAA
45

Element Lab No. Average 1s n z-score Method

Bromine (mg/kg) Lab 18 2.75 0.22 6 -0.4 INAA

Calcium (%) Lab 18 0.232% 0.044% 5 -0.8 INAA

Cerium (mg/kg) Lab 18 0.097 0.025 6 -1.2 INAA

Cobalt (mg/kg) Lab 18 0.060 0.004 6 -0.2 INAA

Iron (mg/kg) Lab 18 42.7 4.6 6 -0.7 INAA

Lanthanum (mg/kg) Lab 18 0.049 0.011 6 -0.8 INAA

Potassium (%) Lab 18 0.402% 0.032% 6 -0.4 INAA

Rubidium (mg/kg) Lab 18 15.3 1.6 6 -0.7 INAA

Samarium (mg/kg) Lab 18 0.0078 0.0008 6 0.1 INAA

Scandium (mg/kg) Lab 18 0.0086 0.0007 6 -1.5 INAA

Sodium (mg/kg) Lab 18 61 5 6 -0.3 INAA

Zinc (mg/kg) Lab 18 34.7 3.1 6 -0.9 INAA
46

Element Lab No. Average 1s n z-score Method

Arsenic (mg/kg) Lab 19 0.036 0.005 6 -0.8 INAA

Barium (mg/kg) Lab 19 5.4 0.4 6 -1.0 INAA

Cesium (mg/kg) Lab 19 0.289 0.009 6 0.2 INAA

Chromium (mg/kg) Lab 19 0.366 0.02 6 1.0 INAA

Cobalt (mg/kg) Lab 19 0.065 0.001 6 0.7 INAA

Iron (mg/kg) Lab 19 47.3 1.3 6 0.3 INAA

Lanthanum (mg/kg) Lab 19 0.050 0.004 6 -0.6 INAA

Potassium (%) Lab 19 0.383% 0.003% 6 -0.8 INAA

Rubidium (mg/kg) Lab 19 16.1 0.2 6 -0.2 INAA

Scandium (mg/kg) Lab 19 0.0110 0.0004 6 0.9 INAA

Sodium (mg/kg) Lab 19 57 1 6 -0.9 INAA

Zinc (mg/kg) Lab 19 37.2 0.5 6 -0.2 INAA
47

Element Lab No. Average 1s n z-score Method

Antimony (mg/kg) Lab 20 0.0086 0.00046 3 -0.5 INAA

Arsenic (mg/kg) Lab 20 0.040 0.003 3 0.3 INAA

Barium (mg/kg) Lab 20 4.96 0.30 3 -1.7 INAA

Bromine (mg/kg) Lab 20 2.72 0.14 3 -0.5 INAA

Calcium (%) Lab 20 0.247% 0.012% 3 -0.2 INAA

Cerium (mg/kg) Lab 20 0.0981 0.0057 3 -1.1 INAA

Cesium (mg/kg) Lab 20 0.266 0.014 3 -0.6 INAA

Chromium (mg/kg) Lab 20 0.365 0.020 3 0.9 INAA

Cobalt (mg/kg) Lab 20 0.0645 0.0037 3 0.6 INAA

Europium (mg/kg) Lab 20 0.00144 0.00012 3 INAA

Gold (mg/kg) Lab 20 0.00026 0.000042 3 INAA

Hafnium (mg/kg) Lab 20 0.0128 0.0016 3 INAA

Iron (mg/kg) Lab 20 46.4 2.7 3 0.1 INAA

Lanthanum (mg/kg) Lab 20 0.0479 0.0028 3 -1.0 INAA

Lutecium (mg/kg) Lab 20 0.00055 0.00006 3 INAA

Mercury (mg/kg) Lab 20 0.0391 0.0028 3 -2.7 INAA

Potassium (%) Lab 20 0.422% 0.019% 3 0.1 INAA

Rubidium (mg/kg) Lab 20 16.73 0.76 3 0.1 INAA

Samarium (mg/kg) Lab 20 0.0070 0.00044 3 -1.0 INAA

Scandium (mg/kg) Lab 20 0.0104 0.0006 3 0.3 INAA

Selenium (mg/kg) Lab 20 0.0985 0.0063 3 -0.1 INAA

Sodium (mg/kg) Lab 20 64.7 3.1 3 0.3 INAA

Strontium (mg/kg) Lab 20 6.76 0.41 3 -0.1 INAA

Tantalum (mg/kg) Lab 20 0.00135 0.00012 3 INAA

Terbium (mg/kg) Lab 20 0.00053 0.00010 1 INAA

Thorium (mg/kg) Lab 20 0.0142 0.0007 3 -1.1 INAA

Ytterbium (mg/kg) Lab 20 0.00215 0.00026 3 INAA

Zinc (mg/kg) Lab 20 37.6 2.0 3 -0.1 INAA
48

Element Lab No. Average 1s n z-score Method

Bromine (mg/kg) Lab 21 2.76 0.09 6 -0.4 INAA

Calcium (%) Lab 21 0.243% 0.010% 6 -0.3 INAA

Cesium (mg/kg) Lab 21 0.276 0.012 6 -0.2 INAA

Cobalt (mg/kg) Lab 21 0.0628 0.0030 6 0.3 INAA

Iron (mg/kg) Lab 21 46.2 1.5 6 0.0 INAA

Potassium (%) Lab 21 0.397% 0.006% 6 -0.5 INAA

Rubidium (mg/kg) Lab 21 17.0 0.5 6 0.3 INAA

Scandium (mg/kg) Lab 21 0.0103 0.0002 6 0.2 INAA

Sodium (mg/kg) Lab 21 61.8 2.0 6 -0.2 INAA

Zinc (mg/kg) Lab 21 36.5 0.6 6 -0.4 INAA
49

Element Lab No. Average 1s n z-score Method

Boron (mg/kg) Lab 23 <20 3 E-6010

Calcium (%) Lab 23 0.246% 0.001% 3 -0.2 E-6010

Copper (mg/kg) Lab 23 3 0 3 0.7 E-6010

Iron (mg/kg) Lab 23 41 0 3 -1.1 E-6010

Magnesium (%) Lab 23 0.100% 0.001% 3 -0.6 E-6010

Manganese (mg/kg) Lab 23 473 2 3 -0.3 E-6010

Nitrogen (%) [TKN] Lab 23 1.11% 0.01% 5 ASTM#1402-07

Phosphorus (%) Lab 23 0.124% 0.001% 5 1.6 ASTM#1402-07

Potassium (%) Lab 23 0.393% 0.003% 3 -0.6 E-6010

Sulfur (%) Lab 23 0.102% 0.001% 3 ASTM#1552-90

Zinc (mg/kg) Lab 23 38 0 3 0.0 E-6010
50

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 24 430 17 4 -2.6 INAA

Antimony (mg/kg) Lab 24 0.0200 0.006 4 12.2 INAA

Arsenic (mg/kg) Lab 24 0.047 0.006 4 2.1 INAA

Bromine (mg/kg) Lab 24 2.83 0.07 4 -0.1 INAA

Calcium (%) Lab 24 0.273% 0.041% 4 0.9 INAA

Chlorine (mg/kg) Lab 24 382 32 4 -0.9 INAA

Lanthanum (mg/kg) Lab 24 0.222 0.070 4 31.7 INAA

Magnesium (%) Lab 24 0.062% 0.027% 1 -4.2 INAA

Manganese (mg/kg) Lab 24 436 14 4 -1.1 INAA

Molybdenum

(mg/kg)

Lab 24 <0.4 4 INAA

Nickel (mg/kg) Lab 24 1.54 0.21 4 0.5 INAA

Potassium (%) Lab 24 0.435% 0.003% 4 0.4 INAA

Samarium (mg/kg) Lab 24 0.0090 0.002 4 1.7 INAA

Sodium (mg/kg) Lab 24 93.0 4.1 4 4.8 INAA

Uranium (mg/kg) Lab 24 <0.08 4 INAA

Vanadium (mg/kg) Lab 24 <0.34 4 INAA

Vanadium (mg/kg) Lab 24 <0.08 4 INAA
51

Appendix E Analytical Results for Each Element Reported by Participants Compared

with Certificate Values and Interlaboratory Averages
52

Element Lab No. Average 1s n z-score Method

Aluminum (mg/kg) Lab 15b 786 67 4 3.6 FAAS/GFAAS

Lab 17 567 20 3 -0.2 INAA

Lab 24 430 17 4 -2.6 INAA

Lab 3 580 19 2 0.0 INAA

Lab 8 553 55 6 -0.5 INAA

all ASTM data Avg ± 1s 583 128 5 number rejected

after rejection Avg ± 1s 533 69 4 1

NIST 575 16 23 INAA

USGS 589 29 16 ICP-AES

Certificate Value Certified 580 ± 30

Element Lab No. Average 1s n z-score Method

Antimony (mg/kg) Lab 13b 0.0330 0.007 3 26.7 INAA

Lab 16 0.0062 0.0012 11 -3.1 INAA

Lab 17 0.0230 0.002 3 15.6 INAA

Lab 20 0.0086 0.00046 3 -0.5 INAA

Lab 24 0.0200 0.006 4 12.2 INAA

Lab 3 0.0120 0.001 1 3.3 INAA

Lab 6 0.0099 0.0035 4 1.0 INAA

Lab 8 0.0083 0.0012 6 -0.8 INAA

all ASTM data Avg ± 1s 0.015 0.009 8 number rejected

after rejection Avg ± 1s 0.009 0.001 4 4

Element Lab No. Average 1s n z-score Method

Arsenic (mg/kg) Lab 13a 0.104 0.019 2 16.7 INAA

Lab 17 0.038 0.002 3 -0.3 INAA

Lab 19 0.036 0.005 6 -0.8 INAA

Lab 20 0.040 0.003 3 0.3 INAA

Lab 24 0.047 0.006 4 2.1 INAA

Lab 3 0.047 0.009 2 2.1 INAA

Lab 6 0.037 0.008 4 -0.5 INAA

Lab 8 0.037 0.006 6 -0.5 INAA

all ASTM data Avg ± 1s 0.0483 0.023 10 number rejected

after rejection Avg ± 1s 0.0403 0.005 9 1

NIST 0.0389 0.00123 8 INAA

Certificate Value Reference 0.039 ±

0.002
53

Element Lab No. Average 1s n z-score Method

Barium (mg/kg) Lab 13a 9.5 1.7 3 5.8 INAA

Lab 13b 8.8 2.4 3 4.7 INAA

Lab 16 4.0 0.3 8 -3.3 INAA

Lab 19 5.4 0.4 6 -1.0 INAA

Lab 20 4.96 0.30 3 -1.7 INAA

Lab 3 5.2 1 2 -1.3 INAA

Lab 6 5.7 2.3 4 -0.5 INAA

Lab 8 5.9 0.6 6 -0.2 INAA

all ASTM data Avg ± 1s 6.2 1.9 8 number rejected

after rejection Avg ± 1s 5.4 0.4 5 3

NIST 5.96 0.45 10 INAA

NIST 6.06 0.43 6 ICP-MS

Certificate Value Certified 6.0 ± 0.2

Element Lab No. Average 1s n z-score Method

Boron (mg/kg) Lab 23 <20 3 E-6010

NIST 9.59 0.07 8 PGAA

Certificate Value Reference 9.6 ± 0.2

Element Lab No. Average 1s n z-score Method

Bromine (mg/kg) Lab 13a 3.08 0.16 5 0.7 INAA

Lab 13b 3.91 0.43 3 3.6 INAA

Lab 15a 3.38 0.16 1 1.8 AAS

Lab 16 2.1 0.4 8 -2.7 INAA

Lab 17 2.7 0.1 3 -0.6 INAA

Lab 18 2.75 0.22 6 -0.4 INAA

Lab 20 2.72 0.14 3 -0.5 INAA

Lab 21 2.76 0.09 6 -0.4 INAA

Lab 24 2.83 0.07 4 -0.1 INAA

Lab 3 3.16 0.1 2 1.0 INAA

Lab 4 2.966 0.248 6 0.4 INAA

Lab 6 2.84 0.07 4 -0.1 INAA

Lab 8 3.1 0.3 6 0.8 INAA

all ASTM data Avg ± 1s 2.95 0.42 13 number rejected

after rejection Avg ± 1s 2.87 0.32 12 1
54

Element Lab No. Average 1s n z-score Method

Cadmium (mg/kg) Lab 15b 0.360 0.040 2 5.5 FAAS/GFAAS

Lab 16 0.0119 0.0025 5 -9.5 INAA

Lab 3 0.252 0.014 2 0.8 INAA

all ASTM data Avg ± 1s 0.208 0.178 3 number rejected

after rejection only Lab 3 0.252 0.014 1 2

NIST 0.233 0.009 9 RNAA

NIST 0.234 0.003 6 ICP-MS

Certificate Value Certified 0.233 ±

0.004

Element Lab No. Average 1s n z-score Method

Calcium (%) Lab 13c 0.457% 1 8.2 AAS

Lab 15b 0.194% 0.029% 4 -2.3 FAAS/GFAAS

Lab 16 0.15% 0.01% 10 -4.0 INAA

Lab 17 0.254% 0.013% 3 0.1 INAA

Lab 18 0.232% 0.044% 5 -0.8 INAA

Lab 20 0.247% 0.012% 3 -0.2 INAA

Lab 21 0.243% 0.010% 6 -0.3 INAA

Lab 23 0.246% 0.001% 3 -0.2 E-6010

Lab 24 0.273% 0.041% 4 0.9 INAA

Lab 3 0.252% 0.014% 2 0.0 INAA

Lab 6 0.240% 0.024% 4 -0.4 INAA

Lab 8 0.243% 0.036% 6 -0.3 INAA

all ASTM data Avg ± 1s 0.253% 0.072% 12 number rejected

after rejection Avg ± 1s 0.242% 0.020% 10 2

NIST 0.248% 0.007% 24 INAA

USGS 0.250% 0.013% 16 ICP-MS

USGS 0.258% 0.012% 16 ICP-AES

Certificate Value Certified 0.25% ± 0.02%
55

Element Lab No. Average 1s n z-score Method

Cerium (mg/kg) Lab 13b 0.74 0.10 3 57.3 INAA

Lab 16 0.0783 0.0015 7 -2.9 INAA

Lab 18 0.097 0.025 6 -1.2 INAA

Lab 20 0.0981 0.0057 3 -1.1 INAA

Lab 3 0.114 0.017 2 0.4 INAA

Lab 6 0.119 0.028 4 0.8 INAA

Lab 8 <0.16 6 INAA

all ASTM data Avg ± 1s 0.208 0.261 6 number rejected

after rejection Avg ± 1s 0.101 0.016 5 1

NIST 0.11 0.01 10 INAA

Certificate Value Information 0.11

Element Lab No. Average 1s n z-score Method

Cesium (mg/kg) Lab 13a 0.270 0.017 3 -0.5 INAA

Lab 13b 0.293 0.023 3 0.4 INAA

Lab 16 0.1991 0.0096 8 -3.0 INAA

Lab 17 0.28 0.01 3 -0.1 INAA

Lab 19 0.289 0.009 6 0.2 INAA

Lab 20 0.266 0.014 3 -0.6 INAA

Lab 21 0.276 0.012 6 -0.2 INAA

Lab 3 0.30 0.01 2 0.6 INAA

Lab 6 0.286 0.012 4 0.1 INAA

Lab 8 0.30 0.03 6 0.6 INAA

all ASTM data Avg ± 1s 0.276 0.029 10 number rejected

after rejection 0

NIST 0.283 0.003 10 INAA

Certificate Value Reference 0.283 ±

0.009
56

Element Lab No. Average 1s n z-score Method

Chlorine (mg/kg) Lab 17 391 15 3 -0.7 INAA

Lab 24 382 32 4 -0.9 INAA

Lab 3 389 17 2 -0.8 INAA

Lab 6 396 21 4 -0.6 INAA

Lab 8 438 44 6 0.4 INAA

all ASTM data Avg ± 1s 399 22 5 number rejected

after rejection 0

NIST 417 4.9 8 PGAA

NIST 425 7.6 24 INAA

Certificate Value Certified 421 ± 7

Element Lab No. Average 1s n z-score Method

Chromium (mg/kg) Lab 13a 1.33 0.33 6 29.9 INAA

Lab 13b 2.37 0.2 3 61.0 INAA

Lab 15b 0.32 0.06 2 -0.4 FAAS/GFAAS

Lab 16 0.268 0.006 9 -2.0 INAA

Lab 17 0.37 0.02 3 1.1 INAA

Lab 19 0.366 0.02 6 1.0 INAA

Lab 20 0.365 0.020 3 0.9 INAA

Lab 3 0.36 0.03 2 0.8 INAA

Lab 6 0.290 0.051 4 -1.3 INAA

Lab 8 0.33 0.1 6 -0.1 INAA

all ASTM data Avg ± 1s 0.637 0.686 10 number rejected

after rejection 0.334 0.039 8 2

NIST 0.375 0.065 10 INAA

USGS 0.32 0.02 16 ICP-AES

USGS 0.39 0.03 16 ICP-MS

Certificate Value Information 0.03 - 0.05
57

Element Lab No. Average 1s n z-score Method

Cobalt (mg/kg) Lab 10 0.0598 0.0048 3 -0.2 INAA

Lab 13a 0.501 0.117 3 72.1 INAA

Lab 13b 0.541 0.130 3 78.7 INAA

Lab 15b <0.035 1 FAAS/GFAAS

Lab 16 0.0452 0.0028 8 -2.6 INAA

Lab 17 0.062 0.003 3 0.2 INAA

Lab 18 0.060 0.004 6 -0.2 INAA

Lab 19 0.065 0.001 6 0.7 INAA

Lab 20 0.0645 0.0037 3 0.6 INAA

Lab 21 0.0628 0.0030 6 0.3 INAA

Lab 3 0.074 0.003 2 2.1 INAA

Lab 4 0.0686 0.0064 6 1.2 INAA

Lab 6 0.060 0.005 4 -0.2 INAA

Lab 8 0.067 0.010 6 1.0 INAA

all ASTM data Avg ± 1s 0.133 0.172 13 number rejected

after rejection 0.063 0.007 11 2

NIST 0.0614 0.0008 10 INAA

Certificate Value Reference 0.061 ±

0.002

Element Lab No. Average 1s n z-score Method

Copper (mg/kg) Lab 15b 1.86 0.18 2 -3.4 FAAS/GFAAS

Lab 23 3 0 3 0.7 E-6010

Lab 3 3.9 0.6 2 3.9 INAA

all ASTM data Avg ± 1s 2.920 1.022 3 number rejected

after rejection only Lab 23 3 0 1 2

NIST 2.89 0.03 8 RNAA

USGS 2.70 0.17 16 ICP-AES

Certificate Value Certified 2.8 ± 0.2

Element Lab No. Average 1s n z-score Method

Europium (mg/kg) Lab 16 0.0011 0.0002 5 INAA

Lab 20 0.00144 0.00012 3 INAA

Lab 4 0.0017 0.0006 6 INAA

Lab 6 <0.002 4 INAA

Lab 8 <0.03 6 INAA
58

Element Lab No. Average 1s n z-score Method

Fluorine (mg/kg) Lab 3 389 20 2 INAA

Element Lab No. Average 1s n z-score Method

Gallium (mg/kg) Lab 3 <1 2 INAA

Element Lab No. Average 1s n z-score Method

Gold (mg/kg) Lab 13a 0.00150 0.0004 3 INAA

Lab 16 0.00070 0.0001 9 INAA

Lab 20 0.00026 0.000042 3 INAA

Lab 3 0.00056 0.00018 2 INAA

Lab 8 0.00260 0.0005 6 INAA

Element Lab No. Average 1s n z-score Method

Hafnium (mg/kg) Lab 13a 0.116 0.026 3 INAA

Lab 13b 0.122 0.025 3 INAA

Lab 16 0.0063 0.0007 7 INAA

Lab 20 0.0128 0.0016 3 INAA

Lab 3 0.014 0.02 2 INAA

Lab 8 <0.015 6 INAA

Element Lab No. Average 1s n z-score Method

Indium (mg/kg) Lab 3 <0.003 2 INAA

Element Lab No. Average 1s n z-score Method

Iodine (mg/kg) Lab 3 <1.5 2 INAA

Element Lab No. Average 1s n z-score Method

Iridium (mg/kg) Lab 3 <0.0001 2 INAA
59

Element Lab No. Average 1s n z-score Method

Iron (mg/kg) Lab 13a 192 19 6 32 INAA

Lab 13b 208 19 3 35 INAA

Lab 13c 49.9 1 0.8 AAS

Lab 15b 43.5 5.6 4 -0.5 FAAS/GFAAS

Lab 16 32.4 0.1 3 -3.0 INAA

Lab 17 45 3 3 -0.2 INAA

Lab 18 42.7 4.6 6 -0.7 INAA

Lab 19 47.3 1.3 6 0.3 INAA

Lab 20 46.4 2.7 3 0.1 INAA

Lab 21 46.2 1.5 6 0.0 INAA

Lab 23 41 0 3 -1.1 E-6010

Lab 3 51.4 2.2 2 1.2 INAA

Lab 4 50.0 5.6 6 0.9 INAA

Lab 6 43.3 3.0 4 -0.6 INAA

Lab 8 48 6 6 0.4 INAA

all ASTM data Avg ± 1s 65.8 54.8 15 number rejected

after rejection Avg ± 1s 45.2 4.9 13 2

NIST 45.85 0.45 10 INAA

USGS 46.01 2.31 16 ICP-AES

Certificate Value Certified 46 ± 2

Element Lab No. Average 1s n z-score Method

Lanthanum (mg/kg) Lab 13a 0.335 0.022 3 53.0 INAA

Lab 13b 0.389 0.03 3 63.1 INAA

Lab 16 0.0416 0.0049 8 -2.2 INAA

Lab 18 0.049 0.011 6 -0.8 INAA

Lab 19 0.050 0.004 6 -0.6 INAA

Lab 20 0.0479 0.0028 3 -1.0 INAA

Lab 24 0.222 0.070 4 31.7 INAA

Lab 3 0.0565 0.0050 2 0.6 INAA

Lab 4 0.0565 0.0057 6 0.6 INAA

Lab 6 0.066 0.012 4 2.4 INAA

Lab 8 0.058 0.009 6 0.9 INAA

all ASTM data Avg ± 1s 0.125 0.128 11 number rejected

after rejection Avg ± 1s 0.053 0.008 8 3
60

Element Lab No. Average 1s n z-score Method

Lead (mg/kg) Lab 15b 0.115 0.031 4 -3.1 FAAS/GFAAS

NIST 0.167 0.013 6 ICP-MS

Certificate Value Reference 0.167 ±

0.015

Element Lab No. Average 1s n z-score Method

Lutecium (mg/kg) Lab 16 0.0006 0.0001 7 INAA

Lab 20 0.00055 0.00006 3 INAA

Element Lab No. Average 1s n z-score Method

Magnesium (%) Lab 13c 0.110% 0.4 AAS

Lab 15b 0.123% 0.009% 4 1.6 FAAS/GFAAS

Lab 17 0.096% 0.003% 3 -0.9 INAA

Lab 23 0.100% 0.001% 3 -0.6 E-6010

Lab 24 0.062% 0.027% 1 -4.2 INAA

Lab 3 0.109% 0.012% 2 0.3 INAA

Lab 6 0.096% 0.018% 4 -1.0 INAA

Lab 8 0.102% 0.017% 6 -0.3 INAA

all ASTM data Avg ± 1s 0.100% 0.018% 8 number rejected

after rejection Avg ± 1s 0.105% 0.010% 7 1

NIST 0.1058% 0.0074% 22 INAA

Certificate Value Reference 0.106% ± 0.017%

Element Lab No. Average 1s n z-score Method

Manganese (mg/kg) Lab 13a 506 47 4 0.4 INAA

Lab 13c 309 -3.7 AAS

Lab 15a 452 13 1 -0.7 AAS

Lab 15b 405 40 4 -1.7 FAAS/GFAAS

Lab 17 474 15 3 -0.3 INAA

Lab 23 473 2 3 -0.3 E-6010

Lab 24 436 14 4 -1.1 INAA

Lab 3 502 16 2 0.3 INAA

Lab 6 475.1 6.4 4 -0.3 INAA

Lab 8 465 46 6 -0.5 INAA

all ASTM data Avg ± 1s 449.7 57.6 10 number rejected

after rejection Avg ± 1s 465.3 31.4 9 1

NIST 488 6 24 INAA

Certificate Value Reference 488 ± 8
61

Element Lab No. Average 1s n z-score Method

Mercury (mg/kg) Lab 16 0.0035 0.0003 6 -9.1 INAA

Lab 20 0.0391 0.0028 3 -2.7 INAA

Lab 3 0.029 0.007 2 -0.2 INAA

all ASTM data Avg ± 1s 0.024 0.018 3 number rejected

after rejection Avg ± 1s 0.034 0.007 2 1

NIST 0.03993 0.00041 5 CV-IDMS

NIST 0.0414 0.0029 7 RNAA

Certificate Value Certified 0.0399 ± 0.0007

Element Lab No. Average 1s n z-score Method

Molybdenum (mg/kg) Lab 10 0.0124 0.0012 4 INAA

Lab 24 <0.4 4 INAA

Lab 3 <0.1 2 INAA

Element Lab No. Average 1s n z-score Method

Neodymium (mg/kg) Lab 16 0.0283 2 INAA

Element Lab No. Average 1s n z-score Method

Nickel (mg/kg) Lab 15b 1.10 0.04 2 -2.5 FAAS/GFAAS

Lab 16 0.9 0.1 6 -3.9 INAA

Lab 24 1.54 0.21 4 0.5 INAA

Lab 3 <1.3 2 INAA

Lab 8 1.29 0.19 6 -1.2 INAA

all ASTM data Avg ± 1s 1.208 0.273 4 number rejected

after rejection Avg ± 1s 1.310 0.221 3 1

NIST 1.475 0.095 6 ICP-MS

Certificate Value Reference 1.47 ± 0.10

Element Lab No. Average 1s n z-score Method

Nitrogen (%) [TKN] Lab 23 1.11% 0.01% 5 ASTM#1402-07
62

Element Lab No. Average 1s n z-score Method

Phosphorus (%) Lab 13a 0.112% 0.009% 10 0.5 INAA

Lab 23 0.124% 0.001% 5 1.6 ASTM#1402-07

all ASTM data Avg ± 1s 0.118% 0.849% 2 number rejected

after rejection Avg ± 1s 0.118% 0.849% 2 0

NIST 0.1023% 0.0020% 10 RNAA

USGS 0.1120% 0.0050% 16 ICP-AES

Certificate Value Certified 0.107% ± 0.008%

Element Lab No. Average 1s n z-score Method

Potassium (%) Lab 13a 0.431% 0.048% 7 0.3 INAA

Lab 13b 0.467% 0.096% 3 1.2 INAA

Lab 13c 0.289% -3.1 AAS

Lab 15a 0.398% 0.078% 1 -0.5 AAS

Lab 15b 0.44% 0.02% 4 0.6 FAAS/GFAAS

Lab 16 0.59% 0.17% 3 4.1 INAA

Lab 17 0.408% 0.015% 3 -0.2 INAA

Lab 18 0.402% 0.032% 6 -0.4 INAA

Lab 19 0.383% 0.003% 6 -0.8 INAA

Lab 20 0.422% 0.019% 3 0.1 INAA

Lab 21 0.397% 0.006% 6 -0.5 INAA

Lab 23 0.393% 0.003% 3 -0.6 E-6010

Lab 24 0.435% 0.003% 4 0.4 INAA

Lab 3 0.404% 0.015% 2 -0.3 INAA

Lab 6 0.3971% 0.0081% 4 -0.5 INAA

Lab 8 0.426% 0.085% 6 0.2 INAA

all ASTM data Avg ± 1s 0.418% 0.060% 16 number rejected

after rejection Avg ± 1s 0.415% 0.023% 14 2

NIST 0.4137% 0.0037% 8 PGAA

NIST 0.4209% 0.0128% 24 INAA

Certificate Value Certified 0.417% ± 0.007%
63

Element Lab No. Average 1s n z-score Method

Rubidium (mg/kg) Lab 10 16.18 1.62 3 -0.2 INAA

Lab 13a 16.4 0.5 3 -0.1 INAA

Lab 13b 17.2 1.3 3 0.4 INAA

Lab 16 0.0115 0.0004 8 -10.0 INAA

Lab 17 16.2 0.05 3 -0.2 INAA

Lab 18 15.3 1.6 6 -0.7 INAA

Lab 19 16.1 0.2 6 -0.2 INAA

Lab 20 16.73 0.76 3 0.1 INAA

Lab 21 17.0 0.5 6 0.3 INAA

Lab 3 16.4 0.5 2 -0.1 INAA

Lab 4 15.8 2.8 6 -0.4 INAA

Lab 6 17.1 0.5 4 0.4 INAA

Lab 8 18.1 1.8 6 1.0 INAA

all ASTM data Avg ± 1s 15.3 4.6 13 number rejected

after rejection Avg ± 1s 16.5 0.7 12 1

NIST 16.55 0.143 10 INAA

USGS 16.36 0.81 16 ICP-MS

Certificate Value Certified 16.5 ± 0.9

Element Lab No. Average 1s n z-score Method

Samarium (mg/kg) Lab 13b 0.0420 0.003 3 44.5 INAA

Lab 16 0.0059 0.0008 9 -2.3 INAA

Lab 18 0.0078 0.0008 6 0.1 INAA

Lab 20 0.0070 0.00044 3 -1.0 INAA

Lab 24 0.0090 0.002 4 1.7 INAA

Lab 3 0.0078 0.0004 2 0.1 INAA

Lab 4 0.0080 0.00071 6 0.3 INAA

Lab 6 0.0080 0.0016 4 0.4 INAA

Lab 8 0.0082 0.0008 6 0.6 INAA

all ASTM data Avg ± 1s 0.012 0.011 9 number rejected

after rejection Avg ± 1s 0.0077 0.0009 8 1
64

Element Lab No. Average 1s n z-score Method

Scandium (mg/kg) Lab 10 0.0117 0.0009 3 1.6 INAA

Lab 13a 0.097 0.012 3 86.0 INAA

Lab 13b 0.098 0.009 3 87.0 INAA

Lab 16 0.0074 0.0001 7 -2.7 INAA

Lab 17 0.0108 0.0004 3 0.7 INAA

Lab 18 0.0086 0.0007 6 -1.5 INAA

Lab 19 0.0110 0.0004 6 0.9 INAA

Lab 20 0.0104 0.0006 3 0.3 INAA

Lab 21 0.0103 0.0002 6 0.2 INAA

Lab 3 0.0116 0.0005 2 1.5 INAA

Lab 4 0.0106 0.0008 6 0.5 INAA

Lab 6 0.0097 0.0005 4 -0.4 INAA

Lab 8 0.0126 0.0025 6 2.5 INAA

all ASTM data Avg ± 1s 0.024 0.033 13 number rejected

after rejection Avg ± 1s 0.0104 0.0015 11 2

NIST 0.01006 0.00015 10 INAA

Certificate Value Reference 0.0101 ± 0.0003

Element Lab No. Average 1s n z-score Method

Selenium (mg/kg) Lab 13b 0.017 0.002 3 -8.3 INAA

Lab 16 0.0696 0.0066 8 -3.0 INAA

Lab 20 0.0985 0.0063 3 -0.1 INAA

Lab 3 0.13 0.02 2 3.1 INAA

Lab 4 0.113 0.010 6 1.4 INAA

Lab 8 0.13 0.03 6 3.1 INAA

all ASTM data Avg ± 1s 0.093 0.044 6 number rejected

after rejection Avg ± 1s 0.094 0.022 3 3

NIST 0.099 0.004 10 INAA

Certificate Value Reference 0.099 ±

0.004

Element Lab No. Average 1s n z-score Method

Silver (mg/kg) Lab 15b <0.05 1 FAAS/GFAAS

Lab 16 0.0118 2 INAA

Lab 3 <0.03 2 INAA
65

Element Lab No. Average 1s n z-score Method

Sodium (mg/kg) Lab 13a 111 36 7 7.6 INAA

Lab 13c 133 11.1 AAS

Lab 15a 73.2 5.5 1 1.6 AAS

Lab 15b 52.6 5.0 4 -1.7 FAAS/GFAAS

Lab 16 72.5 9.3 4 1.5 INAA

Lab 17 67 3 3 0.6 INAA

Lab 18 61 5 6 -0.3 INAA

Lab 19 57 1 6 -0.9 INAA

Lab 20 64.7 3.1 3 0.3 INAA

Lab 21 61.8 2.0 6 -0.2 INAA

Lab 24 93.0 4.1 4 4.8 INAA

Lab 3 63.0 2.4 2 0.0 INAA

Lab 6 56.1 1.0 4 -1.1 INAA

all ASTM data Avg ± 1s 74.3 23.9 13 number rejected

after rejection Avg ± 1s 62.9 6.7 10 3

NIST 62.7 1.63 24 INAA

Certificate Value Reference 63 ± 1

Element Lab No. Average 1s n z-score Method

Strontium (mg/kg) Lab 16 4.9 0.7 4 -2.8 INAA

Lab 20 6.76 0.41 3 -0.1 INAA

Lab 3 7.2 1.3 2 0.5 INAA

Lab 8 8.5 0.8 6 2.4 INAA

all ASTM data Avg ± 1s 6.8 1.5 4 number rejected

after rejection Avg ± 1s 0

Element Lab No. Average 1s n z-score Method

Sulfur (%) Lab 23 0.102% 0.001% 3 ASTM#1552-90

Element Lab No. Average 1s n z-score Method

Tantalum (mg/kg) Lab 16 0.0011 0.0001 5 INAA

Lab 20 0.00135 0.00012 3 INAA

Lab 3 <0.005 1 INAA

Lab 8 0.0028 0.0007 6 INAA
66

Element Lab No. Average 1s n z-score Method

Terbium (mg/kg) Lab 16 0.0008 0.0001 4 INAA

Lab 20 0.00053 0.00010 1 INAA

Element Lab No. Average 1s n z-score Method

Thorium (mg/kg) Lab 13a 0.205 0.032 3 118 INAA

Lab 13b 0.195 0.029 3 112 INAA

Lab 16 0.010 0.0002 7 -3.8 INAA

Lab 20 0.0142 0.0007 3 -1.1 INAA

Lab 3 0.016 0.002 2 0.0 INAA

Lab 6 0.0178 0.0055 4 1.1 INAA

Lab 8 0.016 0.002 6 0.0 INAA

all ASTM data Avg ± 1s 0.068 0.0905 7 number rejected

after rejection Avg ± 1s 0.016 0.001 4 3

Element Lab No. Average 1s n z-score Method

Tungsten (mg/kg) Lab 8 0.065 0.019 6 INAA

Element Lab No. Average 1s n z-score Method

Uranium (mg/kg) Lab 10 0.0071 0.0011 4 INAA

Lab 16 0.0122 2 INAA

Lab 24 <0.08 4 INAA

Lab 3 <0.04 1 INAA

Lab 8 0.0068 0.0014 6 INAA

Element Lab No. Average 1s n z-score Method

Vanadium (mg/kg) Lab 24 <0.34 4 INAA

Lab 24 <0.08 4 INAA

Lab 3 <0.26 2 INAA

Lab 8 <0.27 6 INAA
67

Element Lab No. Average 1s n z-score Method

Ytterbium (mg/kg) Lab 13b 0.025 0.005 3 INAA

Lab 16 0.0033 0.0007 6 INAA

Lab 20 0.00215 0.00026 3 INAA

Element Lab No. Average 1s n z-score Method

Zinc (mg/kg) A334 Lab 10 39.3 2.0 3 0.3 INAA

Lab 13a 51.5 2.9 3 3.6 INAA

Lab 13b 50.4 7.0 3 3.3 INAA

Lab 13c 49.9 3.1 AAS

Lab 15b 29.9 3 4 -2.1 FAAS/GFAAS

Lab 16 27.3 0.3 9 -2.8 INAA

Lab 17 38.3 2.0 3 0.1 INAA

Lab 18 34.7 3.1 6 -0.9 INAA

Lab 19 37.2 0.5 6 -0.2 INAA

Lab 20 37.6 2.0 3 -0.1 INAA

Lab 21 36.5 0.6 6 -0.4 INAA

Lab 23 38 0 3 0.0 E-6010

Lab 3 38.5 2.0 2 0.1 INAA

Lab 4 40.2 2.5 6 0.6 INAA

Lab 6 37.6 1.0 4 -0.1 INAA

Lab 8 38.2 3.8 6 0.1 INAA

all ASTM data Avg ± 1s 39.1 6.6 16 number rejected

after rejection Avg ± 1s 36.4 3.7 13 3

NIST 38.0 0.2 10 INAA

USGS 37.7 1.8 16 ICP-AES

Certificate Value Certified 38 ± 2

Isotope Lab No. Average 1s n z-score Method

U-238 Lab 2 0.00490 0.00083 6 Isotope Analysis

Th-232 Lab 2 0.0270 0.0055 6 Isotope Analysis