Elements by ICP (Microwave Digestion) (7304)

NIOSH Manual of Analytical Methods (1994)
National Institute for Occupational Safety and Health
Elements by ICP (Microwave Digestion) (7304)
2003058NIOSH Manual of Analytical Methods — Elements by ICP (Microwave Digestion) (7304)1994National Institute for Occupational Safety and Health

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*

  • See SPECIAL PRECAUTIONS

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**

    • Acid wash all glassware and vessels before using.

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.

  • Other OELs: Because exposure limits and guidelines may change over time, NIOSH recommends

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