# Elements by ICP (Hot Block/HCl/HNO3 Digestion) (7303)

​ELEMENTS by ICP (Hot Block/HCl/HNO3 Digestion) MW: Table 1
7303
CAS: Table 2
METHOD: 7303, Issue 1
RTECS: Table 2
EVALUATION: PARTIAL
OSHA: Table 2 NIOSH: Table 2 ACGIH: Table 2
Issue 1: 15 March 2003
PROPERTIES: Table 1
ELEMENTS: aluminum antimony* arsenic barium beryllium bismuth* boron
cadmium calcium chromium cobalt copper gallium gold
indium iron lead* magnesium manganese molybdenum neodymium
nickel palladium phosphorus platinum potassium selenium sodium
strontium tellurium thallium tin* titanium vanadium yttrium
zinc
SAMPLING SAMPLER:
FILTER (0.8-:m, cellulose ester membrane)
FLOW RATE:
1 to 4 L/min
VOL-MIN: -MAX:
Table 1 Table 1
SHIPMENT:
Routine
SAMPLE STABILITY:
Stable
BLANKS:
2 to 10 field blanks per set ACCURACY
MEASUREMENT TECHNIQUE:
INDUCTIVELY COUPLED ARGON PLASMA, ATOMIC EMISSION SPECTROSCOPY
ANALYTE:
See element list above
REAGENTS:
Conc. HCl, 1.25 mL; and conc. HNO3 , 1.25 mL
FINAL SOLUTION:
5% HCl and 5% HNO3 , 25 mL
WAVELENGTH:
Element and instrument specific
BACKGROUND CORRECTION:
Spectral wavelength shift
CALIBRATION:
Elements in 5% HCl, 5% HNO3 LOQ to 50,000 :g/sample [1]
RANGE STUDIED:
5,000 to 50,000 :g/sample
RANGE:
BIAS:
Not determined
ESTIMATED LOD: Varies with element; Table 1
OVERALL PRECISION:
Not determined
ACCURACY:
Not determined
PRECISION (Š):
Not evaluated
APPLICABILITY: The working range of this method is up to 100 mg/m3 for each element in a 500-L sample (the minimum range depends on the LOD for each sample; see Table 1). The analysis is not compound specific. Certain elemental compounds are known to be acceptable or unacceptable by this method (see Table 3). For unverified compounds, a test run should be conducted using a known amount of the compound in question to determine acceptability. INTERFERENCES: Interferences are spectral in nature and are accounted for by choosing appropriate wavelengths, applying interelement correction factors, and background correction. OTHER METHODS: Alternative, more sensitive methods exist for some elements by graphite furnace atomic absorption spectroscopy. This method is similar to NIOSH Method 7301, differing only in the use of the hot block for digestion of the sampler.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ​ELEMENTS by ICP (Hot Block/HCl/HNO3 Ashing): METHOD 7303, Issue 1, dated 15 March 2003 - Page 2 of 6 EQUIPMENT:
REAGENTS: 1. Hydrochloric acid,* conc., ultra pure. 2. Nitric acid,* conc., ultra pure. 3. Calibration stock solutions, 50-1000 :g/mL. Com mercially available single element solutions or multielement solutions prepared as instructed by the instrumen t man ufacturer. 4. Argon, prepurified. 5. Distilled, deionized, Type II water. 6. Diluting solution: 5% HCl : 5% HNO 3. To about 600 m L of deionized water in a 1-L volumetric flask, slowly add 50 mL conc. HCl and 50 m L conc. H NO 3. Dilute to the m ark with deionized water.
1. Sam pler: cellulose ester mem brane filter, 0.8:m pore size, 37 -m m diam eter; in c ass ette filter holder. 2. Personal sa m pling pum p, 1 to 4 L/m in, with flexible connecting tubing. 3. Ind uctively coupled arg on plasm a-ato m ic emission spectrometer, equipped as specified by the m anu facturer for an alysis of elem ents of interest. 4. Hot block apparatus at 95 / C. 5. Digestion vessels and caps, 50-mL. 6. W atchglasses. 7. Pip ette s, e lectronic and m echanical. 8. Regulator, two-stage, for argon. 9. Forceps.
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. Sa m ple at an acc urate ly kn ow n flo w rate betwe en 1 and 4 L/m in for a to tal sam ple size of 20 0 to 2000 L for T W A m eas urem ents . Do not exce ed a filter loading of a ppro xim ately 2 m g total dust.
SAMPLE PREPARATION: 3. Open the cassette filter holder and with forceps remove the sample filter. Fold the filter into quarters taking care not to lose any sample, and transfer to a clean, 50-mL hot block digestion tube. 4. Add 1.25 mL HCl. Cover with a plastic watchglass. Place in the hot block and heat at an internal temperature of 95 / C for 15 minutes. NOTE: The internal temperature may vary from the digital readout. Calibrate th e ho t block prior to digestion. 5. Rem ove the sample from the hot block and cool for 5 minutes. Remove watchglass and add 1.25 mL HNO 3. Replace watchglass and return to hot block at 95 / C for 15 minutes. 6. Rem ove the sample from the hot block and coo l for at least 5 m inutes . Rinse wa tchg lass into the sam ple container and discard watchglass. 7. Dilute to 25-mL final volum e with distilled, deionized Type II water.
CALIBRATION AND QUALITY CONTRO L: 8. Ca librate the spec trom eter a cco rding to the manufacturer's recomm endations. Use standards consisting of the same 5% HCl : 5% HNO 3 matrix as the samples. 9. Analyze a standard every 10 samples. 10. Analyze a media blank every 20 samples, and a reagent blank every 10 samples. 11. Analyze a set of two laboratory control samples every 40 samples of a given matrix for a given analyte. 12. Check recoveries with at least two spiked media blanks per ten samples. NOTE: In the determination of lead, there may be a measurem ent interference (for example, samples with high alum inum levels). More recen t instrum ents have a correction for this.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ​ELEMENTS by ICP (Hot Block/HCl/HNO3 Ashing): METHOD 7303, Issue 1, dated 15 March 2003 - Page 3 of 6 MEASUREMENT: 13. Set spec trome ter to conditions spe cified by manufac turer. 14. Analyze standards, samples and quality control checks. NOTE: If the elemental value for a sam ple is above the linear ran ge of the elem ent(s) in que stion, d ilute the sample solution with 5% HCl : 5% HNO 3 diluting solution, reanalyze a nd apply the appro priate dilution factor in the calculations.
CALCULATIONS: 15. Obta in the solution con cen trations for the sam ple, C s (:g/mL), and the average m edia blank , C b (:g/m L), from the ins trum ent. 16. Using the solution volumes of sam ple, V s (m L), an d 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):
NO TE : :g/L / m g/m 3
EVALUATION OF METHOD: The m eth od was evaluated for all elements and compounds listed in Table 1 and Table 2 between 1999 and 2001 using known am oun ts of b ulk m aterial [4]. Evaluation is ongoing for additional elements and com pounds. The limits of detection and quantitation were also determined for each element. Two ICP instruments were used in the evalua tion, a Thermal Jarrell Ash Model 61E [5] and a TJA IRIS [6], operated acc ording to the m anu facturer's instru ctions .
REFERENCES: [1] W OHL [2001]. Metals validation using hot block digestion, Unpublished data. W isconsin Occupational He alth La bora tory, Madison, W I. [2] NIOSH [1994]. Metho d 73 00: E lem ents by ICP , NIO SH Ma nua l of Analytical Metho ds, F ourth Edition, Issue 2, Aug. 15, 1994. [3] W OHL [2001]. Metals Manual 2001, W OHL Inte rnal D ocum ent, Update d Apr. 1, 2 001. W isconsin Oc cup ationa l Hea lth Lab orato ry, Madison, W I. [4] W OHL [2001]. W OHL G eneral Operations Procedures Manual, W OHL Internal Docum ent, Updated 200 1. W isconsin Oc cup ationa l Hea lth Lab orato ry, Madison, W I. [5] Thermal Jarrell Ash [1991]. IC AP 61E P lasm a Spectrom ete r O perator's M anual, The rm al Jarrell Ash Corp., Part No. 128832-01, Feb., 1991. [6] Thermal Jarrell Ash [1997]. IRIS Plasm a Spectro m eter User's Guide, Thermal Jarrell Ash Corp., Part No. 135811-0, Feb. 4, 1997.
METHOD WRITTEN BY: Jason Loughrin, Lyle Reichmann, Doug Sm ieja, Shakker Amer, Curtis Hedman W isconsin Oc cupational Health Labora tory (W OH L).
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ​ELEMENTS by ICP (Hot Block/HCl/HNO3 Ashing): METHOD 7303, Issue 1, dated 15 March 2003 - Page 4 of 6 TABLE 1: ANALYTE INFORMATION FOR VALID ELEMENTS AND COMPOUNDS Properties Analyte Al As Au B Ba Be Bi Ca CaO Cd Co Cr Cu Fe Fe 2O 3 (as Fe) Ga In Mg MgO Mn Mo Nd Ni P Pb Pd Pt Sb Se Sn Sr Te Ti Tl V Y Zn ZnO
LOD (:g/mL)
LOQ (:g/mL)
MW 26.98 74.92 196.97 10.81 137.34 9.01 208.98 40.08 56.08 112 .4 58.93 52.00 63.54 55.85 159.69
MP (°C) 660 817 10.63 2177 3.51 2178 271 842 2927 321 1495 1890 1083 1535 1462
0.111 0.009 0.015 0.0094 0.0018 0.00075 0.025 0.099 0.139 0.0037 0.003 0.009 0.020 0.070 0.070
0.37 0.03 0.05 0.0283 0.006 0.0025 0.085 0.33 0.462 0.012 0.011 0.03 0.060 0.20 0.20
69.72 114.82 24.31 40.32 54.94 95.94 92.906 58.71 30.97 207.19 106 .4 195.09 121.75 78.96 118.69 87.62 127.60 47.90 204.37 50.94 88.91 65.37 81.37
29.75 156.3 651 2825 1244 651 2477 1453 44 328 1550 1769 630.5 217 232 769 450 1675 304 1890 1495 419 1970
0.03 0.015 0.047 0.078 0.0012 0.0072 0.01 0.012 0.3 0.023 0.009 0.0045 0.018 0.021 0.015 0.002 0.15 0.005 0.044 0.003 0.001 0.022 0.027
0.09 0.05 0.14 0.23 0.004 0.024 0.03 0.039 1.0 0.07 0.03 0.015 0.06 0.064 0.05 0.006 0.5 0.016 0.133 0.01 0.003 0.066 0.082
Estimated LOQ (:g/sam ple)* 9.25 0.075 1.25 0.71 0.15 0.062 2.12 8.25 11.6 0.30 0.27 0.75 1.50 5.00 5.00
M inim um ** air vol. (L)
2.25 1.25 3.50 5.75 0.10 0.60 0.75 0.98 25 1.75 0.75 0.38 1.50 1.60 1.25 0.15 12.5 0.40 3.32 0.25 0.075 1.65 2.05
2 8 1 1 1 35 1 2 3 3 3 8 15 1 1 1 15 1 5 0.05 0.5 0.1 1 250 35 0.1 200 3 8 1 300 125 0.1 35 2.5 0.1 0.5 0.5
M axim um *** air vol. (L) 10,000 5,000,000 3,300 3,300 100,000 25,000,00 10,000 10,000 10,000 500,000 500,000 500,000 500,000 5,000 5,000 3,300 500,000 10,000 33,000 10,000 10,000 3,300 50,000 500,000 100,000 3,300 25,000,000 100,000 250,000 25,000 100,000,000 500,000 10,000 500,000 500,000 50,000 10,000 10,000
Value based on a 25-mL sample volume. The minimum sampling volume needed to obtain the OSHA PEL at the LOQ for the element/compound at a sample digestion volume of 25 m L. The m aximum sampling volume for a given sample, calculated by taking 50,000 :g as th e lim it for the element/compound per sample. NOTE: The LOD and LOQ values are dependent on the particular analytical instrument used. Also, LOD and LOQ values may vary for a particular elemen t due to certain interelement interferences.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ​ELEMENTS by ICP (Hot Block/HCl/HNO3 Ashing): METHOD 7303, Issue 1, dated 15 March 2003 - Page 5 of 6 TABLE 2. EXPOSURE LIMITS, CAS #, RTECS Element (Symbol)
OSHA
Exposure Limits, mg/m3 (Ca = carcinogen) 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 ​ELEMENTS by ICP (Hot Block/HCl/HNO3 Ashing): METHOD 7303, Issue 1, dated 15 March 2003 - Page 6 of 6 TABLE 3: VALIDATION SUMMARY Status1
Analyte
Analyte
Status
Analyte
Status
Ag
Not Valid
CuO
Valid
S
Not Valid
Al
Valid
Fe
Valid
Sb
Partially Valid4
Not Valid
Fe2O3
Valid
Sb2O3
Partially Valid5
As
Valid
Ga
Valid
Se
Valid
Au
Valid
In
Valid
Si
Not Valid
B
Valid
KCI
Pending
Sn
Partially Valid6
Ba
Pending
Mg
Valid
SnO
Pending
BaO
Pending
MgO
Valid
SnO2
Pending
BaO2
Pending
Mn
Valid
Sr
Valid
BaCl2
Valid
MnO
Valid
SrCrO4
Valid (by Cr)
BaSO4
Pending
Mo
Valid
Te
Valid
Be
Valid
NaCl
Pending
Ti
Valid
Bi
Partially Valid2
Nd
Valid
Tl
Valid
Ca
Valid
Ni
Valid
V
Valid
CaCO3
Valid
P
Valid
V2O5
Valid
Al2O3
3
CaO
Valid
Pb
Partially Valid
Y
Valid
Cd
Valid
PbCrO4
Valid (by Cr)
Zn
Valid
Co
Valid
PbO
Valid
ZnO
Valid
Cr
Valid
Pd
Valid
Zr
Not Valid
Cu
Valid
Pt
Valid
ZrO
Not Valid
1
Status definitions
2 3
4 5 6
Valid:
The method is suitable for samples up to at least 0.0500 g bulk material with recoveries of between 90 and 110 percent. This weight exceeds most expected levels encountered in work environments.
Partially Valid:
The m eth od is suita ble with bulk-material recoveries of between 90 and 110 percent under certain conditions (as footnoted abo ve).
Not Valid:
The method procedure is not suitable for samples at any weight with recoveries of between 90 and 110 percent. An alternative method should be used.
Valid up to 10,000 :g/sample and within 7 days of sample digestion. Va lid up to 50,000 :g/sample and at least 2 4 ho urs after s am ple digestion ; Valid up to 15,000 :g/s am ple within 24 hours of sample digestion. Valid up to 25,000 :g/sample and within 7 days of sample digestion. Valid up to 25,000 :g/sample and within 7 days of sample digestion. Valid up to 30,000 :g/sample and within 7 days of sample digestion.
NOTE:
The upper limits of the method can be extended by serial dilution of the samples at the time of analyses.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition