Elements by ICP (Aqua Regia Ashing) (7301)

NIOSH Manual of Analytical Methods (1994)
National Institute for Occupational Safety and Health
Elements by ICP (Aqua Regia Ashing) (7301)
2003055NIOSH Manual of Analytical Methods — Elements by ICP (Aqua Regia Ashing) (7301)1994National Institute for Occupational Safety and Health

ELEMENTS by ICP (Aqua Regia Ashing) MW: Table 1 METHOD: 7301, Issue 1

CAS: Table 2

RTECS: Table 2

EVALUATION: PARTIAL

Issue 1: 15 March 2003

PROPERTIES: Table 1

OSHA : Table 2 NIOSH: Table 2 ACGIH: Table 2 ELEMENTS:

7301

aluminum* antimony* arsenic barium beryllium cadmium

calcium chromium* cobalt copper iron* lanthanum

lead* lithium magnesium manganese molybdenum nickel

phosphorus potassium selenium silver strontium tellurium

thallium tin titanium tungsten* vanadium yttrium

zinc zirconium*

  • Some compounds of those elements require special sample treatment.

SAMPLING

MEASUREMENT

SAMPLER:

FILTER (0.8-µm, cellulose ester membrane, or 5.0-µm, polyvinyl chloride membrane)

TECHNIQUE:

INDUCTIVELY COUPLED ARGON PLASMA, ATOMIC EMISSION SPECTROSCOPY (ICP-AES)

FLOW RATE:

1 to 4 L/min

ANALYTE:

Elements above

VOL-MIN: -MAX:

Table 1 Table 1

ASHING REAGENTS:

Aqua regia (1 HNO3 : 3 HCl)

SHIPMENT:

Routine

CONDITIONS:

SAMPLE STABILITY:

Stable

FINAL SOLUTION:

5% aqua regia, 25 mL

BLANKS:

2 to 10 field blanks per set WAVELENGTH:

Depends upon element, Table 3

BACKGROUND CORRECTION:

Spectral wavelength shift

CALIBRATION:

Elements in 5% aqua regia

RANGE:

Varies with element [1]

ESTIMATED LOD:

Tables 3 and 4

PRECISION ( þ r ):

Tables 3 and 4

ACCURACY RANGE STUDIED:

Not determined

BIAS:

Not determined

OVERALL PRECISION (Ö r T ):

Not determined

ACCURACY:

Not determined

Room temperature, 30 min; 150 °C to near dryness

APPLICABILITY: The working range of this method is 0.005 to 2.0 mg/m3 for each element in a 500-L air sample. This is simultaneous elemental analysis, not compound specific. Verify that the types of compounds in the samples are soluble with the ashing procedure selected. This method does not digest PVC filters completely.

INTERFERENCES: Spectral interferences are the primary interferences encountered in ICP-AES analysis. These are minimized by judicious wavelength selection, interelement correction factors and background correction [1-4].

OTHER METHODS: Flame atomic absorption spectroscopy (e.g., Methods 70XX) is an alternate analytical technique for many of these elements. Graphite furnace AAS (e.g., 7102 for Be, 7105 for Pb) is more sensitive. NIOSH Methods 7300 & 7302 are alternative digestion procedures.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 2 o f 8 REAGENTS:

EQUIPMENT:

1. Nitric acid (HNO 3), conc.*, ultra pure. 2. Hydrochloric acid (HCl), conc.*, ultra pure. 3. Ashing acid (Aqua Regia): 1:3 (v/v) HNO 3:HC l. Mix 1 volume conc. HNO 3 with 3 volumes conc. HCl. 4. Ca libration s tock solutions, 1000 µg/m L. Com mercially available, or prepared per instrument manufacturer's recomm endation (see step 12 ). 5. Dilution acid, 1% HNO 3, 3% HCl. Add 50 mL ashing acid to 600 mL water; dilute to 1 L. 6. Argon. 7. Distilled,deionized water.

1. Sam pler: cellulose ester m em brane filter, 0.8-µm pore size; or polyvinyl chloride (PVC) m em brane, 5.0-µm pore size; 37-m m diam eter, in cassette filter holder. 2. Personal sa m pling pum p, 1 to 4 L/m in, 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. Beakers, Phillips, 125-mL, or Griffin, 50-mL, with watch glass c overs .** 6. Volum etric flasks , 10-, 25-,10 0-m L., and 1-L ** 7. Ass orted vo lum etric pipets as need ed.** 8. Hotplate, surface temperature 150 °C.

See SPECIAL PRECAUTIONS.

Clean all glasswa re with conc. nitric acid and rinse thoroughly in distilled water before use.

SPECIAL PRECAUTIONS: Conce ntrate d ac ids are po werful oxidizers, toxic, an d co rrosive liquids . W ear protective clothing and work in a fume hood.

SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Sam ple at a n ac curately kn own flow ra te betwee n 1 and 4 L/m in for a total sam ple size of 200 to 2000 L (see Table 1) for TW A measurem ents. Do not exceed a filter loading of approximately 2 mg total dust.

SAMPLE PREPARATION: 3. Open the cassette filter holders and transfer the samples and blanks to clean beakers. 4. Add 5 mL ashing acid. Cover with a watchglass. Let stand 30 min at room tem perature. NOTE: Start a reagent blank at this step. 5. Heat on hotplate (120 °C) until ca. 0.5 mL remains. NOT E 1: Reco very of lead from some paint matrices may require other digestion tech niqu es. See Method 7082 (Lead by Flame AA S) for an alternative hotplate digestion procedure or Method 730 2 for a m icrow ave diges tion pro ced ure. NOTE 2: So m e species of Al, Be , Co, C r, Li, Mo, S b, W , and Z r will not be com pletely solubilized by this procedure. Alternative solubilization techniques for m ost of these elements can be found elsewhe re [5-1 0]. 6. Add 2 m L ashing acid and repeat step 5. Rep eat this step until the solution is clear. NOT E: PVC filters will not completely dissolve after repeated additions of ashing acid. 7. Rem ove watchg lass and rinse into the beake r with distilled water. 8. Increase the tem perature to 150 °C and take the s am ple to near dryness (ca. 0.5 m L). 9. Dissolve the residue in 2 to 3 mL dilution acid. 10. Transfer the solutions quantitatively to 25-mL volumetric flasks. 11. Dilute to volume with dilution acid.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 3 o f 8 CALIBRATION AND QUALITY CONTRO L: 12. Calibrate the spectrometer according to the manufacturer’s recomm endations. NOTE: Typically, an acid blank and 1.0 µg/m L multielement working standards are used. The following multielement combinations are chemically compatible in 5% Aqua Regia: a. Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, La, In, Na b. Ag, K, Li, Mg, Mn, Ni, P, Pb, Se, Sr, Tl, V, Y, Zn, Sc c. Mo, Sb, Sn, Te, Ti, W , Zr d. Acid blank 13. Analyze a standard for every ten samples. 14. Check recoveries with at least two spiked media blanks per ten samples.

MEASUREMENT: 15. Set spec trome ter to conditions spe cified by manufac turer. 16. Analyze standards, samples, and blanks. NOTE: If the va lues for the sam ples are a bove the rang e of th e standa rds, dilute the solutions w ith dilution acid, reanalyze a nd apply the appropriate dilution fac tor in the calcula tions. If more sensitivity is required, the final sample volume may be held to 10.0 mL.

CALCULATIONS: 17. Obtain the solution concentrations for the sample, C s (µg/m L), an d the average m edia blank , C b (µg/m L), from the ins trum ent. 18. Using the solution volum es o f sam ple, V s (m L), and m edia blank , V b (mL), calculate the concentration, C (m g/m 3), of each elem ent in the air volum e sam pled, V (L):

NOT E: µg/L / m g/m 3

EVALUATION OF METHOD: The precision and recovery data were determined at approximately 3x and 10x the instrumental detection limits on com m ercially prepared s pike d filters [12] using 25 .0 m L as the final sample volume. The precision and recovery data, instrumental detection lim its, and ana lytical wave lengths are listed in Ta bles 3 and 4. In general, better recoveries were obtained from MCE filters than from PVC filters. The values in Tables 3 and 4 were determined with a Spectro Analytical Instruments model EOP opera ted according to m anufa cturer's instructions.

REFERENCES: [1] Millson M, Andrews R [2002]. Backup data report, Method 7301, unpublished report, NIOSH/DART. [2] Hull RD [1981]. Multielement Analysis of Industrial Hygiene Sam ples, NIO SH Internal Re port, presented at the American Industrial Hygiene Conference, Portland, Oregon. [3] NIOSH [1982]. NIOSH Manual of Analytical Methods, 2nd ed., V. 7, P&CAM 351 (Elements by ICP), U.S. Department of Health and Human Services, Publ. (NIOSH) 82-100. [4] NIOSH [1994]. Elem ents by ICP : Method 7300. In: Eller PM, Cassinelli ME, eds., NIOSH M anual of Analytical Me thod s, 4 th 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. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 4 o f 8 [5] NIOSH [1994]. Lead by FAAS: Method 7082. In: Eller PM, Cassinelli ME, eds., NIOSH Manual of Analytical Me thod s, 4 th ed. Cincinnati, OH: U.S. Depa rtmen t of Health and Hu m an Services, C enters for Dise ase Control an d Prevention, N ationa l Institute for Occu pation al Safety and Health, DHHS (NIOSH) Publication No. 94-113. [6] NIOSH [1977]. NIOSH Manual of Analytical Methods, 2nd ed., V. 2, S5 (Manganese), U.S. Department of Health, Education, and W elfare, Publ. (NIOSH) 77-157-B. [7] NIOSH [1994]. Tungsten, soluble/insoluble: Method 707 4. In: Eller P M, C ass inelli ME , eds., NIOSH Manual of Ana lytical Method s, 4 th 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. [8] NIOSH [1979]. NIOSH Manual of Analytical Methods, 2nd ed., V. 5, P&CAM 173 (Metals by Ato m ic Absorption), U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 79-141. [9] NIOSH [1977]. NIOSH Manual of Analytical Methods, 2nd ed., V. 3, S183 (T in), S185 (Zirconium ), and S376 (Molybdenum), U.S. Department of Health, Education, and W elfare, Publ. (NIOSH) 77-157-C. [10] ISO [2001]. W ork place air - D eterm ination of metals and metalloids in airborne particulate matter by inductively coupled plasma atomic emission spectrometry - Part 2: Sample preparation. International Orga nization for Standa rdization. ISO 152 02-2:2001(E ). [11] ASTM [1985]. 1985 Annual Book of ASTM Standards, Vol. 11.01; Standard Specification for Reagent W ater; ASTM , Philadelphia, PA, D11 93-77 (198 5). [12] Certification Inorganic Ventures for spikes.

METHOD WRITTEN BY: Mark Millson, NIOSH/DART, and Ronnee Andrews, NIOSH/DART.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 5 o f 8

TABLE 1. PROPERTIES AND SAMPLING VOLUM ES

Element (Sym bol)

Silver (Ag) Alu m inum (Al) Arsenic (As) Barium (Ba) Beryllium (Be) Calcium (Ca) Cadm ium (Cd) Cobalt (Co) Chrom ium (C r) Copper (Cu) Iron (Fe) Potassium (K) Lanthanum (La) Lith ium (Li) Magnesium (Mg) Manganese (Mn) Molybdenum (Mo) Nick el (N i) Phosphorus (P) Lead (Pb) Antimony (Sb) Selenium (Se) Tin (Sn) Strontium (S r) Tellurium (Te) Titan ium (Ti) Thallium (Tl) Vanadium (V) Tun gsten (W ) Yttrium (Y) Zinc (Zn) Zirconium (Zr)

Properties Ato m ic W eight MP, °C 107.87 26.98 74.92 137.34 9.01 40.08 112.40 58.93 52.00 63.54 55.85 39.10 138.91 6.94 24.31 54.94 95.94 58.71 30.97 207.19 121.75 78.96 118.69 87.62 127.60 47.90 204.37 50.94 183.85 88.91 65.37 91.22

961 660 817 710 1278 842 321 1495 1890 1083 1535 63.65 920 179 651 1244 651 1453 44 328 630 .5 217 231 .9 769 450 1675 304 1890 3410 1495 419 1852

Air Volume, L @ OSHA PEL MIN MAX 250 5 5 50 1250 5 13 25 5 5 5 5 5 100 5 5 5 5 25 50 50 13 5 10 25 5 25 5 50 5 5 5

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

2000 100 2000 2000 2000 200 2000 2000 1000 1000 100 1000 1000 2000 67 200 67 1000 2000 2000 2000 2000 1000 1000 2000 100 2000 2000 1000 1000 200 200 ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 6 o f 8 TABLE 2. EXPOSURE LIMITS, CAS #, RTECS Element (Symbol)

Exposure Limits, mg/m3 (Ca = carcinogen) OSHA NIOSH ACGIH

CAS #

RTECS

Silver (Ag)

7440-22-4

VW3500000

0.01 (dust, fume, metal)

0.01 (metal, soluble)

0.1 (metal) 0.01 (soluble)

Aluminum (Al)

7429-90-5

BD0330000

15 (total dust) 5 (respirable)

10 (total dust) 5 (respirable fume) 2 (salts, alkyls)

10 (dust) 5 (powders, fume) 2 (salts, alkyls)

Arsenic (As)

7440-38-2

CG0525000

varies

C 0.002, Ca

0.01, Ca

Barium (Ba)

7440-39-3

CQ8370000

0.5

0.5

0.5

Beryllium (Be)

7440-41-7

DS1750000

0.002, C 0.005

0.0005, Ca

0.002, Ca

Calcium (Ca)

7440-70-2

--

varies

varies

varies

Cadmium (Cd)

7440-43-9

EU9800000

0.005

lowest feasible, Ca

0.01 (total), Ca 0.002 (respir.), Ca

Cobalt (Co)

7440-48-4

GF8750000

0.1

0.05 (dust, fume)

0.02 (dust, fume)

Chromium (Cr)

7440-47-3

GB4200000

0.5

0.5

0.5

Copper (Cu)

7440-50-8

GL5325000

1 (dust, mists) 0.1 (fume)

1 (dust) 0.1 (fume)

1 (dust, mists) 0.2 (fume)

Iron (Fe)

7439-89-6

NO4565500

10 (dust, fume)

5 (dust, fume)

5 (fume)

Potassium (K)

7440-09-7

TS6460000

--

--

--

Lanthanum

7439-91-0

--

--

Lithium (Li)

7439-93-2

--

--

--

--

Magnesium (Mg)

7439-95-4

OM2100000

15 (dust) as oxide 5 (respirable)

10 (fume) as oxide

10 (fume) as oxide

Manganese (Mn)

7439-96-5

OO9275000

C5

1; STEL 3

5 (dust) 1; STEL 3 (fume)

Molybdenum (Mo)

7439-98-7

QA4680000

5 (soluble) 15 (total insoluble)

5 (soluble) 10 (insoluble)

5 (soluble) 10 (insoluble)

Nickel (Ni)

7440-02-0

QR5950000

1

0.015, Ca

0.1 (soluble) 1 (insoluble, metal)

Phosphorus (P)

7723-14-0

TH3500000

0.1

0.1

0.1

Lead (Pb)

7439-92-1

OF7525000

0.05

0.05

0.05

Antimony (Sb)

7440-36-0

CC4025000

0.5

0.5

0.5

Selenium (Se)

7782-49-2

VS7700000

0.2

0.2

0.2

Tin (Sn)

7440-31-5

XP7320000

2

2

2

Strontium (Sr)

7440-24-6

--

Tellurium (Te)

13494-80-9

WY2625000

0.1

0.1

0.1

Titanium (Ti)

7440-32-6

XR1700000

--

--

--

Thallium (Tl)

7440-28-0

XG3425000

0.1 (skin) (soluble)

0.1 (skin) (soluble)

0.1 (skin)

Vanadium (V)

7440-62-2

YW240000

--

C 0.05

--

Tungsten

7440-33-7

5

5 10 (STEL)

5 10 (STEL)

Yttrium (Y)

7440-65-5

ZG2980000

1

N/A

1

Zinc (Zn)

7440-66-6

ZG8600000

--

--

Zirconium (Zr)

7440-67-7

ZH7070000

5

5, STEL 10

5, STEL 10

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 7 o f 8 TABLE 3.

Element (a) Ag Al As Ba Be Ca Cd Co Cr Cu Fe K La Li Mg Mn Mo Ni P Pb Sb Se Sn Sr Te Ti Tl V W Y Zn Zr

M EASU REM ENT PRO CED UR ES AN D D ATA [1]. M ixed C ellulose Ester Filters (0.45:m ) wavelength Est.LOD (:g/ Filter) (nm )

LOD (ng/mL)

Certified 3x LOD (:g/filter) (b)

328 167 189 455 313 317 226 228 267 324 259 766 408 670 279 257 202 231 178 168 206 196 189 407 214 334 190 292 207 371 213 339

0.042 0.115 0.140 0.005 0.005 0.908 0.0075 0.012 0.020 0.068 0.095 1.73 0.048 0.010 0.098 0.005 0.020 0.020 0.092 0.062 0.192 0.135 0.040 0.005 0.078 0.050 0.092 0.028 0.075 0.012 0.310 0.022

1.7 4.6 5.6 0.2 0.2 36.3 0.3 0.5 0.8 2.7 3.8 69.3 1.9 0.4 3.9 0.2 0.8 0.8 3.7 2.5 7.7 5.4 1.6 0.2 3.1 2.0 3.7 1.1 3.0 0.5 12.4 0.9

0.77 1.54 3.08 0.31 0.31 15.4 0.31 0.31 0.31 1.54 1.54 23.00 0.77 0.31 1.54 0.31 0.31 0.31 1.54 1.54 3.08 2.30 0.77 0.31 1.54 0.77 1.54 0.77 1.54 0.31 4.60 0.31

% Percent Certified 10x LOD Reco very RSD (:g/filter) (N=25) (c) (b) 100 .3 2.39 3.21 42.4 6.40 208 .1 97.6 4.71 12.90 104 .3 1.65 1.29 99.6 1.42 1.29 101 .6 5.01 64.00 106 .8 2.60 1.29 105 .6 1.64 1.29 97.0 27.0 1.29 118 .9 65.2 6.40 114 .9 43.0 6.40 94.7 2.60 96.40 105 .7 1.80 3.21 104 .3 2.37 1.29 105 .2 4.23 6.40 103 .5 1.64 1.29 108 .9 2.70 1.29 112 .2 2.28 1.29 93.2 10.9 6.40 88.0 6.52 6.40 54.7 12.90 50.1 93.2 8.38 9.64 81.9 3.21 25.8 100 .8 1.27 1.29 103 .1 1.88 6.40 98.3 1.88 3.21 101 .3 3.57 6.40 106 .0 1.38 3.21 21.8 6.40 64.9 104 .3 1.55 1.29 99.8 9.73 19.30 71.2 1.29 52.5

% Percent Reco very RSD (N=25) (c) 93.4 99.6 95.1 100 .8 100 .6 101 .6 99.2 100 .4 88.0 102 .0 82.7 95.8 101 .3 99.3 99.2 91.2 97.4 94.2 97.1 102 .2 80.0 89.1 91.7 99.3 95.0 96.0 98.2 101 .3 74.1 99.3 98.0 76.6

4.95 9.43 1.14 1.54 0.68 1.42 0.76 0.87 5.38 0.68 7.81 0.98 0.84 0.89 1.24 2.01 1.25 1.73 5.93 1.06 19.46 7.23 16.39 0.66 1.31 1.06 0.71 0.81 11.34 0.72 0.86 18.19

(a) Bo ld values are qualitative only, because of po or rec overy. (b) Values are certified by Inorganic Ventures INC. at 3x and 10x the approximate instrumental LOD. (c) Values reported were obtained with a Spectro Analytical Instruments EOP ICP; performance m ay vary with instrument and should be independently verified.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S by ICP (Aqu a Reg ia Ashing): MET HO D 730 1, Issue 1, dated 15 M arch 200 3 - Page 8 o f 8 TABLE 4. M EASU REM ENT PRO CED UR ES AN D D ATA [1]. Polyvinyl Chloride Filter (5.0 :m )

Element (a) Ag Al As Ba Be Ca Cd Co Cr Cu Fe K La Li Mg Mn Mo Ni P Pb Sb Se Sn Sr Te Ti Tl V W Y Zn Zr

wavelength Est. LOD (nm) (:g/ Filter)

LOD (ng/mL)

Certified 3x LOD (:g/filter)

(b) 328 167 189 455 313 317 226 228 267 324 259 766 408 670 279 257 202 231 178 168 206 196 189 407 214 334 190 292 207 371 213 339

0.042 0.115 0.140 0.005 0.005 0.908 0.0075 0.012 0.020 0.068 0.095 1.73 0.048 0.010 0.098 0.005 0.020 0.020 0.092 0.062 0.192 0.135 0.040 0.005 0.078 0.050 0.092 0.028 0.075 0.012 0.310 0.022

1.7 4.6 5.6 0.2 0.2 36.3 0.3 0.5 0.8 2.7 3.8 69.3 1.9 0.4 3.9 0.2 0.8 0.8 3.7 2.5 7.7 5.4 1.6 0.2 3.1 2.0 3.7 1.1 3.0 0.5 12.4 0.9

0.78 1.56 3.10 0.31 0.31 15.60 0.31 0.31 0.31 1.56 1.56 23.40 1.78 0.31 1.56 0.31 0.31 0.31 1.56 1.56 3.10 2.30 0.78 0.31 1.56 0.78 1.56 0.78 1.56 0.31 4.70 0.31

% Reco very (c)

57.9 -1.9 78.2 73.0 81.1 68.2 86.7 83.8 80.1 75.9 78.4 61.4 34.4 76.3 77.5 77.4 79.7 86.2 76.9 82.0 40.3 89.4 101 .1 73.4 91.8 53.4 71.6 77.8 51.3 79.6 80.9 46.2

% Percent Percent Certified RSD 10x LOD Reco very RSD (c) (N=25) (N=25) (:g/ filter) (b)

0.2 1.6 0.1 0.1 4.9 0.1 0.1 0.1 0.5 0.6 3.1 0.4 0.0 0.6 0.1 0.2 0.1 0.9 0.9 1.5 1.2 0.4 0.1 0.7 0.2 0.8 0.3 0.8 0.1 2.2 0.1

3.18 6.40 12.70 1.27 1.27 64.00 1.27 1.27 1.27 6.40 6.40 95.00 3.18 1.27 6.40 1.27 1.27 1.27 6.40 6.40 12.70 9.50 3.18 1.27 6.40 3.18 6.40 3.18 6.40 1.27 19.10 1.27

55.0 112 .1 80.2 95.7 97.2 97.7 97.4 99.2 94.1 96.1 88.4 91.6 95.3 96.0 94.0 93.4 89.2 100 .8 69.0 99.4 23.0 87.5 21.1 95.2 85.3 46.3 86.1 96.1 29.8 95.8 94.7 39.2

21.7 59.6 7.9 3.7 4.3 4.5 4.3 4.4 6.8 4.3 9.0 5.7 3.8 4.7 4.6 4.2 9.8 4.8 14.5 4.4 76.5 9.9 124.0 3.9 7.5 39.9 9.3 4.6 47.0 4.4 4.2 112.7

(a) Bo ld values are qualitative only because of po or rec overy. (b) Values are certified by Inorganic Ventures INC. at 3x and 10x the approximate instrumental LOD. (c) Values reported were obtained with a Spectro Ana lytical Instrum ents EO P ICP; perform ance m ay vary with instrument and should be independently verified.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition