# Elements by ICP (Microwave Digestion) (7304)

​7304
ELEMENTS by ICP (Microwave Digestion) MW: Table 1
CAS: Table 2
RTECS: Table 2
METHOD: 7304, Issue 1
EVALUATION: FULL
Issue 1: 25 June 2014
OSHA: Table 2 ​ NIOSH: Table 2 Other OELs:  [1,2]* ELEMENTS:
PROPERTIES:
Table 1
aluminum
cadmium iron molybdenum selenium titanium arsenic calcium lead nickel sodium vanadium barium chromium lithium
phosphorus strontium yttrium beryllium cobalt magnesium platinum tellurium zinc boron copper manganese potassium thallium zirconium SAMPLING
SAMPLER: FILTER, (polyvinyl chloride (PVC), 37-mm diameter, 5.0 µm pore size)
MEASUREMENT TECHNIQUE:
INDUCTIVELY COUPLED ARGON PLASMA, ATOMIC EMISSION SPECTROSCOPY (ICP-AES)
ANALYTE:
Elements listed above
REAGENTS:
12 mL of 5:1 concentrated nitric acid and ASTM Type ll water
FLOW RATE: 1 to 4 L/min VOL-MIN: -MAX:
Table 1
SHIPMENT: Routine
FINAL SOLUTION: 20% HNO3, 50 mL
SAMPLE STABILITY: Stable BLANKS:
2 to 10 field blanks per set ACCURACY
WAVELENGTH:
Depends upon element; Table 3
BACKGROUND CORRECTION:
Spectral wavelength shift
RANGE STUDIED:
See Table 4
CALIBRATION:
Elements in 20% HNO3
ACCURACY:
See Table 4
RANGE:
See Table 4
BIAS:
See Table 4
ESTIMATED LOD: Table 3
OVERALL PRECISION ( SˆrT ): See Table 4
PRECISION ( Sr ): Table 3
APPLICABILITY: The working range of this method varies from element to element. This method is for the analysis of metal and nonmetal dust collected on PVC filters that are also used for gravimetric analysis. This is a simultaneous elemental analysis using a microwave digestion approach to simplify and expedite the analysis. Some elements such as antimony, silver, and tin do not form stable solutions in nitric acid when chloride from the PVC filters is present. In such cases a mixed cellulose ester (MCE) filter is necessary (See NMAM 7302). A different acid medium also helps but this technique is not described in this method. INTERFERENCES: Spectral interferences are the primary interferences encountered in ICP-AES analysis. These are minimized by judicious wavelength selection, inter-element correction factors and background correction. [3,4,5,6] OTHER METHODS:  This method complements NIOSH hotplate digestion methods 7300 and 7301 for trace elements. Flame atomic absorption spectroscopy (e.g., Methods 7013 through 7082) is an alternative analytical technique for many of these elements. [7] Graphite furnace AAS (e.g., 7102 for Be, 7105 for Pb) is usually more sensitive. [7] NMAM 7301 and 7303 contain alternative extraction procedures.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 2 of 11
REAGENTS
EQUIPMENT
1. Nitric acid, conc., trace metal grade* 2. Calibration stock solutions, 1000 ug/mL and 10,000 ug/mL commercially available, or prepared per instrument manufacturer recommendation (see step 10) 3. Argon, liquid 4. De-ionized W ater, ASTM Type ll [8] 5. Dilution acid: 20% nitric acid in ASTM Type ll water*
1. Sampler: Polyvinyl chloride filter, 5.0-µm pore size, 37-mm diameter; in 2-piece cassette filter holder 2. Personal sampling pump, 1 to 4 L/min, with flexible connecting tubing 3. Inductively coupled plasma-atomic emission spectrometer, equipped as specified by the manufacturer for analysis of elements of interest 4. Regulator, two-stage for argon 5. Microwave, programmable power, active temperature control, minimum of 574 W, corrosion resistant ventilated oven and turntable 6. Microwave digestion vessels, high pressure, closed PTFE, 100-mL capacity 7. Volumetric flasks, 50 mL** 8. Assorted volumetric pipettes as needed**
SPECIAL PRECAUTIONS:  Wear gloves, lab coat, and safety glasses while handling all chemicals. All work should be performed with adequate ventilation to personnel and equipment. Because this method involves the use of capped digestion containers, avoid the use of other acids such as perchloric acid in combination with nitric acid that could cause a violent reaction [1,9]. In the preparation of the digestion and dilution acid, it is imperative that acid be added to water in order to avoid a violent exothermic reaction. SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler connected to the pump (in line.) 2. Sample at an accurately known flow rate between 1 and 4 L/min. For estimated sampling volumes see Table 1. For TWA measurements see Table 2. Do not exceed a filter loading of approximately 2 mg total dust. NOTE: Filter overloading can be assessed by periodic visual checks. See NMAM Chapter O, “Factors Affecting Aerosol Sampling,” for additional discussion on filter capacity. [http://www.cdc. gov/niosh/docs/2003-154/pdfs/chapter-o.pdf.] SAMPLE PREPARATION: NOTE: If total weights are desired, it should be done at this step. Follow NIOSH method 0500 for gravimetric analysis [12]. 3. Open the cassette filter holders and transfer the samples, blanks, and Quality Control (QC) filters to clean PTFE digestion digestion vessels. Wipe the internal cassette surfaces with a 37 mm PVC filter wetted with deionized water and add to the digestion vessel to transfer non-filter aerosol deposits into the digestion vessels. 4. Add 2 mL of ASTM Type ll water followed by adding (slowly) 10 mL concentrated nitric acid, then cap each vessel.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 3 of 11
NOTE: In order to avoid a violent exothermic reaction, do not add water to concentrated nitric acid. Acid should be added after the water has been placed in the vessel. 5. Place digestion vessels in microwave and run preprogrammed PVC digestion procedure. Example microwave conditions for 12-vessel digestion: 1200 W power, ramp to 215 °C over 20 min, hold for 10 min at 215 °C followed by at least a 5 min cool down (power will be adjusted lower for fewer vessels). 6. Allow the samples to cool to room temperature. 7. Remove vessel lids and rinse contents into 50-mL volumetric flasks with ASTM Type ll water. 8. Dilute to the mark with ASTM Type ll water and mix. 9. Submit samples for analysis. NOTE: A residual solid may be present after digestion. Filter/centrifuge the samples before analysis, as appropriate. CALIBRATION AND QUALITY CONTROL: 10. Calibrate the spectrometer according to the manufacturers’ recommendations. NOTE: Typically an acid blank and a single or multi-element working standard are used. The following multi-element combinations are chemically compatible in 20% HNO3. a. Al, As, Ba, Be, Ca, Co, Cr, Cu, Fe, Li, Mg, Mn, Mo, Na, Ni, Pb, Se, Sr, Ti, V, Y, Zn, Zr; b. B, K, P, Te, Tl; c. Cd; d. Pt. 11. Analyze all applicable standards at least once every twenty (20) analyses (minimum frequency 5%). 12. Check recoveries with at least one media blank and two spiked media blanks per twenty samples. Use a spike level that is within the range of 10 to 20 times the Limit of Quantitation (LOQ.) NOTE: Whenever possible, QA/QC samples should be prepared from certified reference materials in a matrix similar to the bulk material sampled. Liquid spiked filters are only surrogates for real world samples and QC data based upon certified samples would be ideal. MEASUREMENT: 13. Set the ICP-AES spectrometer to conditions specified by manufacturer. 14. Analyze standards and samples at applicable wavelengths for each element (target analytes are in Table 3). NOTE: If the values for the samples are above the linear range of the instrument, dilute the solutions with dilution acid, reanalyze, and apply the appropriate dilution factor in the calculations. CALCULATIONS: 15. Obtain the solution concentrations for the sample, Cs (µg/mL), and the average media blank, Cb (µg/ mL), from the instrument. 16. Using the solution volume of sample, Vs (mL), and media blank, Vb (mL), calculate the concentration for the sample, C (mg/m3), of each element in the air volume sampled, V (L), as follows:
C=
(Cs Vs )-(Cb Vb ) , mg/m3 V
NOTE: µg/Liter air is equivalent to mg/m3.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 4 of 11
EVALUATION OF METHOD: This method is less time consuming and more convenient than using the acid hotplate approach. The elimination of perchloric acid in the sample digestion procedure helps to improve the safety of the method. [9] Use of the PVC filters allows for the acquisition of total mass per filter in addition to total metals concentration. The evaluation of this method, 7304, for PVC filters was determined at six concentration levels based on the LOQ for each element listed on page 1 [13]. All of the precision data was evaluated for homogeneity for all concentration levels tested using the Bartlett’s test and the results are listed in the method backup data report [12] and summarized in Tables 3 and 4. In many cases the highest concentration level (300 times the LOQ) was not poolable due in every case to the precision being so small relative to the other values, usually less than CV = 0.001 (<0.1%). Therefore, the overall precision (ŜrT) and accuracy as given in Table 4 is an upper limit predictor of precision; precision at concentration levels greater than 300 times the LOQ (see Table 3) will probably be much smaller. For many of the metals, precision at the 3 times and/or 1 times the LOQ levels was reasonable (CV less than 10%) but were not poolable due to the precisions at the higher concentration levels being so much smaller. In one case (strontium) the lowest level was not poolable because its CV was an inlier (less than 1%), being much smaller than those at the higher concentration levels. In most cases the precision appeared to be a function of concentration. This is observable in Table 3 where the CVs for the 10 times the LOQ (lower level) and 300 times the LOQ (higher) levels are compared. Three elements, antimony, silver, and tin, had poor recoveries. It is believed that the chloride ions produced in the digestion of the PVC filters is causing the formation of precipitates. These metals are preferably sampled on MCE filters. The values in Tables 3 and 4 were determined using several different ICP-AES instruments and also several different microwave ovens. All were operated according to the manufacturer’s instructions. REFERENCES: [1] ACGIH [2013]. TLVs and BEIs based on the documentation of the Threshold Limit Values for chemical substances and physical agents and Biological Exposure Indices. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists. [www.acgih.org]. [Data accessed April 2014.] [2] Institut fur Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung [2013]. GESTIS database on hazardous substances (German Social Accident Insurance). Sankt Augustin, FRG: [http://www. dguv.de/ifa/Gefahrstoffdatenbanken/GESTIS-Stoffdatenbank/index-2.jsp]. [Data accessed April 2014.] [3] Hull, RD [1981]. Multi-element analysis of industrial hygiene samples, NIOSH internal report presented at the American Industrial Hygiene Conference, Portland, Oregon, May. [4] NIOSH [1994]. Elements: Method 7300 (Supplement Issued 3/15/2003). In: Schlecht PC, O’Connor PF, eds. NIOSH Manual of analytical methods, 4th ed. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS Publication No. 94-113 [www.cdc.gov/niosh/nmam/]. [5] Harrison, GR [1969]. Massachusetts Institute of Technology wavelength tables, 2nd ed. West Hanover, MA: Halliday Lithograph, Volume 1. [6] ASTM International [2010]. ASTM D7035, Standard test method for the determination of metals and metalloids in airborne particulate matter by inductively coupled plasma atomic emission spectrometry. West Conshohocken, PA: ASTM International [www.astm.org]. [7] NIOSH [1994]. NIOSH manual of analytical methods (NMAM). 4th ed. Schlecht PC, O’Connor PF, eds. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113 [www.cdc.gov/niosh/nmam/]. NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 5 of 11
[8] ASTM [1983]. ASTM D1193-77, Standard specification for reagent water. West Conshohocken, PA: ASTM International [www.astm.org]. [9] Furr KA [1995]. CRC Handbook of Laboratory Safety, 4th ed. Boca Raton, FL: CRC Press. [10] NIOSH [1973]. The industrial environment - its evaluation & control. 3rd ed. U.S. Department of Health Education and Welfare, Center for Disease Control, National Institute for Occupational Safety and Health. DHEW (NIOSH) Publication No. 74-117. [11] NIOSH [1994]. Particulates not otherwise regulated: Method 0500. In: Eller PM, Cassinelli ME, eds. NIOSH Manual of Analytical Methods, 4th ed. Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication No. 94-113. [12] Stone LC, Perkins JB, Rogers DM [2003]. Backup data report NMAM 7304: Elements by ICP on PVC filters using microwave digestion. Cincinnati OH: DataChem Laboratories, Inc. under NIOSH contract CDC-200-2001-08000. Unpublished. [13] Lide DR [1993]. Handbook of chemistry and physics. 74th ed. Boca Raton FL: CRC Press. [14] NIOSH [2005]. NIOSH pocket guide to chemical hazards. Barsan ME, ed. Cincinnati, OH: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 2005-149. [www.cdc. gov/niosh/npg]. [15] Code of Federal Regulations, 29 CFR Part 1910.1000, Table Z-1[2013]. Limits for air standards. National occupational safety and health standards. [https://www.osha.gov/pls/oshaweb/owadisp. show_document?p_table=STANDARDS&p_id=9992] Website accessed on December 13, 2013. METHOD  WRITTEN BY: David M. Rogers, Lee C. Stone, John M. Reynolds, James B. Perkins, DataChem Laboratories, Salt Lake City, Utah; Yvonne Gagnon, Ronnee Andrews, Ph.D., DART/CEMB. Disclaimer: Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health. In addition, citations to Web sites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these Web sites. All Web addresses referenced in this document were accessible at the time of publication.
referring to the following sources for updated limits and guidelines on the use of this compound.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 6 of 11
Table 1. PROPERTIES AND SAMPLING VOLUMES Element (Symbol)
Aluminum (Al) Arsenic (As) Barium (Ba) Boron (B)(1) Beryllium(Be) Calcium (Ca)(1) Cadmium (Cd)(3) Cobalt (Co) Chromium (Cr) Copper (Cu) Iron (Fe) Potassium (K)(1) Lithium (Li)(1) Magnesium (Mg) Manganese (Mn) Molybdenum (Mo) Sodium (Na)(1)(3) Nickel (Ni) Phosphorus (P) Lead (Pb) Platinum (Pt)(3) Selenium (Se) Strontium (Sr)(1) Tellurium (Te) Titanium (Ti) Thallium (Tl) Vanadium (V) Yttrium (Y) Zinc (Zn) Zirconium (Zr)
Properties [13] Atomic Weight
26.98 74.92 137.3 10.81 9.01 40.08 112.40 58.93 52.00 63.54 55.85 39.10 6.94 24.31 54.94 95.94 22.99 58.71 30.97 207.19 195.09 78.96 87.62 127.60 47.90 204.37 50.94 88.91 65.37 91.22
MP, °C
660 817 727 2300 1278 842.5 321 1495 1890 1083 1535 63 179 651 1244 651 98 1453 44 328 1769 217 769 450 1675 304 1890 1495 419 1852
Air Volume, L @ OSHA PEL [4] MIN
MAX
5 5 5(2) 5 1250 5 13 25 5 5 5 5 100 5 5 5 13 5 25 50 1250 13 5 25 5 25 5 5 5 5
100 2000 200(2) 2000 2000 200 2000 2000 1000 1000 100 2000 2000 67 200 67 2000 1000 2000 2000 2000 2000 2000 2000 100 2000 2000 1000 200 200
(1) No PEL, REL, or STEL data found [1,14]. (2) Air Volumes Estimated from TWA and LOQ’s (see Tables 2, 3). [10] (3) These metals, as well as tin and antimony, forms precipitates in nitric acid when chloride from   the PVC filters is present.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 7 of 11
Table 2. EXPOSURE LIMITS, CAS #, RTECS [1,14,15] Exposure Limits, mg/m3 (C = ceiling limit) OSHA NIOSH
Element (Symbol)
CAS #
RTECS #
Aluminum (Al)
7429-90-5
BD0330000
15 (total dust) 5 (respirable)
10 (total dust) 5 (respirable, fume)
Arsenic (As)
7440-38-2
CG0525000
0.010 (inorganic)
C 0.002(1)
Barium (Ba)
7440-39-3
CQ8370000
0.5 (soluble)
0.5 (soluble)
Beryllium (Be)
7440-41-7
DS1750000
0.002, C 0.005
C 0.0005(1)
Cadmium (Cd)
7440-43-9
EU9800000
0.005
lowest feasible conc.(1)
Calcium (Ca)
7440-70-2
No OEL
No OEL
Cobalt (Co)
7440-48-4
GF8750000
0.1
0.05 (dust, fume)
Chromium (II) (Cr)
22541-79-3
GB6260000
0.5
0.5
Chromium (III) (Cr)
16065-83-1
GB6261000
0.5
0.5
Chromium (VI) (Cr)
18540-29-9
GB6262000
0.005
0.0002
Cobalt (Co)
7440-48-4
GF8750000
0.1
0.05 (dust, fume)
Copper (Cu)
7440-50-8
GL5325000
1 (dust, mists) 0.1 (fume)
1 (dust, mists) 0.1 (fume)
Iron (Fe)
1309-37-1
NO7400000
10 (fume) as oxide
5 (dust, fume) as oxide
Magnesium (Mg)
1309-48-4
OM3850000
15 (dust) as oxide
Manganese (Mn)
7439-96-5
OO9275000
C5
1; STEL 3
Molybdenum (Mo)
7439-98-7
QA4680000
5 (soluble) 15 (total insoluble)
Nickel (Ni)
7440-02-0
QR5950000
1
0.015(1)
Phosphorus (P)
7723-14-0
TH3500000
0.1
0.1
Lead (Pb)
7439-92-1
OF7525000
0.05
0.05
Platinum (Pt)
7440-06-4
TP2160000
0.002 (soluble)
1 (metal)
Selenium (Se)
7782-49-2
VS7700000
0.2
0.2
Silver (Ag)
7440-22-4
VW3500000
0.01 (soluble, metal)
0.01 (soluble, metal)
Tellurium (Te)
13494-80-9
WY2625000
0.1
0.1
Titanium (Ti)
7440-32-6
XR1700000
15 (as TiO2)
lowest feasible(1)
Thallium (Tl)
7440-28-0
XG3425000
0.1 (soluble)
0.1(soluble)
Vanadium (V)
7440-62-2
YW240000
C 0.5 (respirable) as V2O5 C 0.1 (fume) as V2O5
C 0.05
Yttrium (Y)
7440-65-5
ZG2980000
1
1
Zinc (Zn)
1314-13-2
ZH4810000
5 (ZnO fume) 15 (ZnO dust) 5 (ZnO respirable)
5; STEL 10 (ZnO fume) 5; C 15 (ZnO dust)
Zirconium (Zr)
7440-67-7
ZH7070000
5
5, STEL 10
(1) Carcinogen
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 8 of 11
Table 3. MEASUREMENT WAVELENGTHS AND RECOVERY DATA Lower Level(4,5) Element
Wavelength (nm)
LOD (µg/ sample)
µg/ sample
N=
Percent Recovery
Ag
328.07
0.1
3.00
5
63.01
Al
308.22
2
50.25(4)
6
89.78
Al(2)
308.214
0.5
15.0
5
As
193.76
2
15.0
5
Ba
493.41
0.2
1.50
B
249.68
0.4
Be
313.04
0.008
Ca
315.89
Ca
(1)
Higher Level(5) Precision
Precision
µg/ N= sample
Percent Recovery
0.0739
300
6
3.92
0.0865
0.0565
1500
6
100.71
0.0055
115.05
0.0199
1500
6
105.17
0.0056
93.29
0.0570
1500
6
115.84
0.0174
5
107.16
0.0295
150
6
102.22
0.0104
7.50
5
86.38
0.0277
750
6
101.19
0.0082
0.152
6
102.38
0.0861
15.2
6
107.71
0.0091
151
6
94.64
0.0512
4500
6
116.25
0.0153
(4)
(Sr)
(Sr)
315.88
2
45.0
5
104.82
0.0090
4500
6
98.13
0.0066
Cd
228.80
0.2
3.00
5
109.65
0.0316
300
6
111.68
0.0152
Co
228.62
0.7
7.50
5
89.87
0.0338
750
6
114.15
0.0141
(2)
Cr
267.72
0.7
7.50
5
112.65
0.0233
750
6
118.65
0.0136
Cr(2) Cu
267.71
0.3
7.50
5
102.60
0.0048
750
6
92.98
0.0066
324.75
0.08
1.50
5
106.84
0.0364
150
6
100.42
0.0058
(2)
Cu
324.75
0.08
1.50
5
117.16
0.0361
150
6
103.13
0.0150
Fe
259.94
15
30
5
120.58
0.0405
3000
6
112.41
0.0083
Fe(2)
259.94
5
30
5
112.55
0.0489
3000
6
97.20
0.0085
K
766.49
3
100(4)
6
85.57
0.0254
3000
6
86.46
0.0260
K
766.49
100
6
99.40
0.0300
3000
6
90.02
0.0205
Li
670.78
0.06
1.50
5
97.51
0.0253
150
6
81.96
0.0378
Mg
279.08
0.9
15.0
5
105.25
0.0088
1500
6
97.47
0.0077
(2)
(4)
Mg
279.07
0.4
15.0
5
107.33
0.0043
1500
6
101.75
0.0058
Mn
257.61
0.09
1.50
5
110.24
0.0150
150
6
115.56
0.0090
Mo
202.03
0.4
4.50
5
87.79
0.0433
450
6
120.57
0.0093
Mo(2)
202.029
0.3
4.50
5
89.75
0.0215
450
6
100.44
0.0154
Na
589.00
5
75.0
6
124.56
0.0859
7500
6
83.07
0.0248
Ni
231.60
0.3
4.50
5
102.93
0.0475
450
6
110.59
0.0080
Ni(2)
231.60
0.2
4.50
5
109.91
0.0047
450
6
101.77
0.0139
P
214.92
2
30.0
5
81.82
0.0511
3000
6
107.20
0.0103
(2)
P
214.91
2
30.0
5
86.36
0.0077
3000
6
103.33
0.0174
Pb
220.35
1
15.0
5
95.85
0.0308
1500
6
100.54
0.0154
Pt
203.65
9
150
5
104.67
0.0182
15000
6
105.19
0.0088
206.84
0.7
15.0
6
25.29
0.5861
1500
6
111.95
0.0086
(2)
Sb
(3)
(1) Values reported were obtained with a Fisons ARL Accuris ICP-AES unless otherwise noted; performance may vary with instrument    and should be independently verified. (2) Values reported were obtained with a Perkin Elmer Optima 3000 DV ICP-AES. (3) Elements that were evaluated and found not suitable for analysis by this method. (4) Values given (lower level) are for the 10xLOQ level due to low recoveries at the 3xLOQ level. (5) LOQ = Estimated limit of quantitation
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 9 of 11
Table 3. MEASUREMENT WAVELENGTHS AND RECOVERY DATA Lower Level(4,5) Element
Wavelength (nm)
LOD (µg/ sample)
µg/ sample
N=
Percent Recovery
Se
196.09
5
75.0
5
102.05
196.02
2
75.0
5
99.93
(1)
Se
(2)
Precision
Precision
µg/ N= sample
Percent Recovery
0.0531
7500
6
111.35
0.0063
0.0051
7500
6
99.72
0.0082
(Sr)
(Sr)
Sn
189.9
75.0
5
30.82
0.0502
7500
6
79.56
0.0124
Sn(2,3)
189.9
0.4
75.0
5
37.87
0.0816
7500
6
92.34
0.0129
Sr
421.55
0.04
7.50
5
100.00
0.0049
750
6
99.54
0.0055
Te
214.27
4
30.0
5
95.80
0.0624
3000
6
110.81
0.0094
Te(2)
214.28
2
30.0
5
97.18
0.0100
3000
6
99.64
0.0074
Ti
337.28
0.2
3.00
5
81.66
0.0392
300
6
103.42
0.0101
Ti
334.94
0.1
3.00
5
82.68
0.0374
300
6
96.13
0.0121
Tl
190.86
2
15.0
5
96.38
0.0605
1500
6
97.25
0.0148
(3)
Tl
190.79
1
15.0
5
97.75
0.0032
1500
6
92.04
0.0119
V
292.40
0.1
1.50
5
104.54
0.0528
150
6
111.15
0.0160
V(2)
292.40
0.09
1.50
5
100.99
0.0146
150
6
99.38
0.0232
Y
371.03
0.07
0.752
5
105.98
0.0245
75.2
6
105.03
0.0073
(3)
Higher Level(5)
Zn
213.85
0.2
3.00
5
110.76
0.0327
300
6
116.84
0.0153
Zn(2)
213.86
0.4
3.00
5
93.45
0.0351
300
6
94.01
0.0055
Zr
339.20
0.2
1.50
5
102.61
0.0242
150
6
101.56
0.0144
(1) Values reported were obtained with a Fisons ARL Accuris ICP-AES unless otherwise noted; performance may vary with instrument    and should be independently verified. (2) Values reported were obtained with a Perkin Elmer Optima 3000 DV ICP-AES. (3) Elements that were evaluated and found not suitable for analysis by this method. (4) Values given (lower level) are for the 10xLOQ level due to low recoveries at the 3xLOQ level. (5) LOQ = Estimated limit of quantitation
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 10 of 11
Table 4. OVERALL PRECISION AND ACCURACY DATA [13] Range Studied (µg/sample)
Bias
Range of Bias
Precision Accuracy (%) SrT
Lowest Level(2)
0.0240
0.0419
9.9
50.25
0.1505
0.0379
15.1
15
Element
Instrument
From
To
From
To
Aluminum
Fisons
5.025
1500
-0.0318
-0.1022
Aluminum
P-E Optima
5.025
1500
0.0833
0.0567
Antimony
Fisons
5.025
1500
Poor and variable recoveries across study range.
(1)
Arsenic
Fisons
5.025
1500
0.0630
-0.0671
0.1584
0.0461
14.3
15
Barium
Fisons
0.5038
150.4
0.0433
0.0222
0.0716
0.0182
7.6
0.5
Beryllium
Fisons
0.0509
15.2
0.0652
0.0366
0.0980
0.0163
9.5
0.0509
Boron
Fisons
2.514
750.4
-0.0387
-0.1362
0.0118
0.0164
6.4
7.504
Cadmium
Fisons
1.005
300.0
0.0923
0.0718
0.1167
0.0307
14.8
1.005
Calcium
Fisons
15.08
4500
0.0779
-0.0536
0.1624
0.0313
13.4
150.75
Calcium
P-E Optima
15.08
4500
0.0453
0.0098
0.0963
0.0245
8.8
15.08
Chromium
Fisons
2.514
750.4
0.1395
0.0974
0.1865
0.0214
18
2.514
Chromium
P-E Optima
2.514
750.4
-0.0018
-0.0701
0.1245
0.0131
<5
2.514
Cobalt
Fisons
2.514
750.4
0.0592
-0.1013
0.1508
0.0264
10.4
7.504
Copper
Fisons
0.5038
150.4
0.0475
0.0272
0.0684
0.0240
8.9
0.5038
Copper
P-E Optima
0.5038
150.4
0.0829
0.0313
0.1716
0.0217
12.1
1.504
Iron
Fisons
10.05
3000
0.1101
0.0630
0.2057
0.0397
18.6
30
Iron
Fisons
10.05
3000
0.0836
0.0630
0.0974
0.0396
15.4
100.5
Iron
P-E Optima
10.05
3000
0.0445
-0.0205
0.1255
0.0404
11.4
30
Lead
Fisons
5.025
1500
-0.0241
-0.0668
0.0124
0.0279
6.9
5.025
Lithium
Fisons
0.5038
150.4
-0.0690
-0.1804
0.0132
0.0276
11.1
0.5038
Magnesium
Fisons
5.025
1500
0.0156
-0.0253
0.0524
0.0171
<5
5.025
Magnesium
P-E Optima
5.025
1500
0.0715
0.0421
0.1372
0.0249
11.5
5.025
Manganese
Fisons
0.5038
150.4
0.1357
0.1005
0.1755
0.0201
17.3
0.5038
Fisons
1.509
450.4
-0.0388
-0.1597
0.1353
0.0795
16.7
1.509
P-E Optima
1.509
450.4
-0.0489
-0.2033
0.0969
0.0179
7.7
1.509
Nickel
Fisons
1.509
450.4
0.0787
0.0293
0.1274
0.0338
13.8
4.504
Nickel
P-E Optima
1.509
450.4
0.0645
0.0177
0.1406
0.0159
9.2
1.509
Phosphorus
Fisons
10.05
3000
-0.0546
-0.1818
0.0011
0.0417
12
30
Phosphorus
P-E Optima
10.05
3000
-0.0163
-0.1364
0.0333
0.0124
<5
10.05
Platinum
Fisons
50
15000
0.0423
0.0097
0.0671
0.0226
8.2
150
Potassium
Fisons
10.05
3000
-0.0909
-0.1443
-0.0316
0.0265
13.1
100.5
Potassium
P-E Optima
10.05
3000
-0.0499
-0.0998
-0.0060
0.0249
8.8
100.5
Selenium
Fisons
25.12
7500
0.0941
0.0675
0.1150
0.0150
12.1
25.12
Selenium
P-E Optima
25.12
7500
0.0026
-0.0027
0.0115
0.0127
<5
25.12
Silver
Fisons
1.005
300
Poor and variable recoveries across study range.
Sodium
Fisons
25.12
7500
-0.0492
-0.1694
0.0718
0.0246
8.8
251.2
Strontium
Fisons
2.514
750.4
0.0172
-0.00002
0.0373
0.0153
<5
2.514
Tellurium
Fisons
10.05
3000
0.0295
-0.0420
0.1037
0.0404
9.8
30
(1) Values reported were obtained with a Fisons ARL Accuris ICP-AES or a Perkin Elmer Optima 3000 DV ICP-AES. (2) Lowest level in range studied at which recoveries were between 81 and 121% recovery and relative standard deviation (Sr)    less than 0.1100 on 5 or 6 replicates. Performance may vary with instrument and should be independently verified.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition ​ELEMENTS by ICP (Microwave Digestion): METHOD 7304, Issue 1, dated 25 June 2014 - Page 11 of 11
Table 4. OVERALL PRECISION AND ACCURACY DATA [13] Range Studied (µg/sample)
Precision Accuracy (%) SrT
Lowest Level(2)
0.0163
0.0155
<5
10.05
0.0334
0.0407
8.2
15
Instrument
From
To
From
To
Tellurium
P-E Optima
10.05
3000
-0.0043
-0.0282
Thallium
Fisons
5.025
1500
-0.0081
-0.0362
Thallium
P-E Optima
5.025
1500
Fisons P-E Optima
25.12
7500
-0.0505 -0.0688 -0.0048 0.0250 9 Poor and variable recoveries across study range.
25.12
7500
Poor and variable recoveries across study range.
Tin Tin Titanium
Bias
Range of Bias
Element
(1)
5.025
Fisons
1.005
300
-0.0827
-0.1834
0.0342
0.0269
12.3
3
Titanium
P-E Optima
1.005
300
-0.1072
-0.1732
-0.0387
0.0321
15.3
1.005
Vanadium
Fisons
0.5038
150.4
0.0704
0.0438
0.1114
0.0195
10.5
0.5038
Vanadium
P-E Optima
0.5038
150.4
-0.0063
-0.0217
0.0099
0.0198
<5
0.5038
Yttrium
Fisons
0.2519
75.2
0.0598
0.0466
0.0795
0.0164
8.9
0.2519
Zinc
Fisons
1.005
300
0.1452
0.0630
0.2976
0.0340
22
1.005
Zinc
Fisons
1.005
300
0.1190
0.0630
0.1683
0.0356
18.7
3
Zinc
P-E Optima
1.005
300
-0.0502
-0.0655
-0.0388
0.0295
9.6
3
Zirconium
Fisons
0.5025
150
0.0164
-0.0096
0.0350
0.0175
<5
0.5025
(1) Values reported were obtained with a Fisons ARL Accuris ICP-AES or a Perkin Elmer Optima 3000 DV ICP-AES. (2) Lowest level in range studied at which recoveries were between 81 and 121% recovery and relative standard deviation (Sr)    less than 0.1100 on 5 or 6 replicates. Performance may vary with instrument and should be independently verified.
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition