ELEMENTS ON WIPES MW: Table 1
CAS: Table 1
METHOD: 9102, Issue 1
RTECS: Table 1
EVALUATION: PARTIAL
Issue 1: 15 March 2003
PROPERTIES: Table 1
OSHA : N/A NIOSH: N/A ACGIH: N/A
ELEMENTS: Arsenic Barium Beryllium Cadmium Cobalt Copper Chromium
Iron Lanthanum Lead Manganese Molybdenum Nickel Phosphorus
Selenium Silver Strontium Tellurium Thallium Vanadium Yttrium
Zinc Zirconium
SAMPLING SAMPLER:
9102
WIPE
MEASUREMENT TECHNIQUE:
INDUCTIVELY COUPLED ARGON PLASMA, ATOMIC EMISSION SPECTROSCOPY (ICP-AES) Elements above
FLOW RATE: N/A VOL-MIN: -MAX:
N/A
ANALYTE:
SHIPMENT:
Routine
ASHING REAGENTS:
SAMPLE STABILITY:
Stable
CONDITIONS:
BLANKS:
2 to 10 field blanks per set
ACCURACY RANGE STUDIED:
Not Studied
BIAS:
Not determined
OVERALL PRECISION (Ö r T ):
Not determined
ACCURACY:
Not determined
Conc. HNO3 , 20 mL; and conc. HClO4 , 1 mL Room temperature, 30 min; 150 °C to near dryness
FINAL SOLUTION:
4% HNO3 , 1% HClO4 , 10 mL
WAVELENGTH:
Table 2
BACKGROUND CORRECTION:
Spectral wavelength shift
CALIBRATION:
Elements in 4% HNO 3 , 1% HClO4
RANGE:
Table 2
ESTIMATED LOD: Table 2 PRECISION ( þ r ):
Table 2
APPLICABILITY: This method is a simultaneous elemental analysis, not compound specific. Verify that the types of compounds in the samples are soluble with the ashing procedure selected. Because this method deals with wipes samples it is important to keep in mind that the values obtained are qualitative. 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. OTHER METHODS: This method supplements NMAM Method 7300 [1]. Additional element methods, whether single element or multi-element, may be found in NMAM. Alternate instrumentation includes flame atomic absorption spectroscopy for certain elements and graphite furnace AAS for increased sensitivity.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S O N W IPES: M ETH OD 9102, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 5 REAGENTS:
EQUIPMENT:
1. 2. 3.
1.
4.
5. 6.
Nitric acid (HNO 3), con c., ultra p ure.* Perchloric acid (HCLO 4), con c., ultra p ure.* Ca libration s tock solutions, 1000 µg/m L comm ercially available, or prepared per instrument manufacturer’s recomm endation (see step 20 ). Dilution acid, 4:1 HNO 3:HC IO 4. Mix 4 volumes conc. HNO 3 with 1 volume conc. HC IO 4. Argon. Distilled, de-ionized water.
- See SPECIAL PRECAUTIONS
2.
3. 4. 5. 6. 7. 8. 9.
Sam pler: W ash ‘n Dri or ASTM equivalent[2] [pre-pac kaged m oist dispos able towe lette (wipe )]. Inductively coupled plasma-atomic emission spectrometer, equipped as specified by the manufacturer for analysis of elements of interest. Regulator, two-stage for argon. Beakers, Phillips, 125-mL, or Griffin, 50-mL, with watch glass c overs .** Volum etric flasks , 10- and 100-m L.** Ass orted vo lum etric pipettes as nee ded.** Hotplate, surface temperature 150oC. Polystyrene centrifuge tubes, 50-mL and 15-mL . Hard-w alled sam ple container.
- Clean all glasswa re with conc. nitric acid
and rinse thorough ly in de-ionized water.
SPECIAL PRECAUTIONS: Nitric and perchloric acids are strong oxidizers and extremely corrosive. Perform all perchloric acid digestions in a perchloric acid hood. When working with acids use gloves and avoid inhalation or contact with skin or clothing.
SAMPLING:[3] 1. W earing a clean pair of powder-less, plastic gloves, place the template over the area to be sampled and secure it. If the area to be sampled is in a confined area and a template cannot be used, measure the sampling area, and delineate the area to be sampled with mask ing tape. 2. Re m ove a wipe from its pac kage, and u nfold it. 3. W ipe the surface to be sam pled using fingertips held tog ethe r and app lying firm pres sure. Us e an overlapping ‘S’ pattern to cover the entire surface with horizontal strokes. 4. Fold the exposed side of the wipe in, and wipe the same area using vertical ‘S’-strokes. 5. Fo ld the wipe again to reveal an unexposed surface, and wipe the surface a third tim e as described in step 3. 6. Fold the wipe, expos ed side in, and place it into a clean hard-wa lled sam ple container (e.g., 50-mL centrifuge tube). Seal securely and label the sam ple container. NOTE: Com positin g of wipe sam ples is not recom m ended, because (a) they cause sam ple prep aration an d an alytical difficu lties, and (b) site-specific a nalytical info rm ation is lost. 7. Clean the tem plate in pre paration for the next w ipe sam ple using water or a wipe. A disposable template may also be used. 8. Rem ove gloves and discard. Clean gloves should be worn for each new sample. 9. Field blanks: 10% of samples, at least three per batch. Remove unexposed wipes from packaging and place into sample containers. The field blanks should be collected at the beginning, middle, and end of sampling.
SAMPLE PREPARATION: 10. Transfer the samples and blanks to clean beakers. 11. Add 20 mL concentrated nitric acid and 1 mL concentrated perchloric acid. Cover beaker with a watchglass. Let stand 30 min at room tem perature. Start a reagent blank at this step. 12. Allow samples to heat for approximately 8 hours @150 °C. 13. Rem ove watchg lass and rinse into the beake r with de-ionized water. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S O N W IPES: M ETH OD 9102, Issue 1, dated 1 5 Ma rch 2003 - Page 3 of 5 14. Continue to heat on h otplate (120 °C). NOTE: Som e species will not be completely solubilized by this procedure. Alternative solubilization techniques for most of these elements can be found elsewhere. 15. Add additional amounts of HNO 3, if necessary, until th e solution is clear an d the wipe m edia is completely destroyed. 16. Tak e the sam ple to near dryness (ca. 0.5 m L). 17. Dissolve the residue in 0.5 mL dilution acid. 18. Transfer the solutions quantitatively to 15-mL centrifuge tubes or 10 mL volumetric flasks. 19. Dilute to 10 mL w ith de-ionized water.
CALIBRATION AND QUALITY CONTRO L: 20. Calibrate the spectrometer according to the manufacturers recomm endations. NOTE: Typically, an acid blank and 10 µg/mL m ulti-element working standards are used. The following m ulti-elem ent co m binatio ns are chem ically and spectrally com patible in 4% HNO 3 /1% HC lO 4: a. Al, As, Ba, Be, Cd, Ca, Cr, Co, Cu, In, Fe, La; b. Pb, Li, Mg, Mn, Ni, P, K, Sc, Se, Ag, Sr, Tl, V, Y, Zn; c. Sb, Mo , Te Sn, T i, W , Zr; d. Pt 21. Analyze a standard for every six samples. 22. Check recoveries with at least two spiked media blanks per ten samples.
MEASUREMENT: 23. Set spec trome ter to conditions spe cified by manufac turer. 24. Analyze standards and samples. NOTE: If the va lues for the sam ples are a bove the rang e of the standa rds, dilute the solutions w ith dilution acid, re-analyze and apply the appropriate dilution factor in the calculations.
CALCULATIONS: 25. Ob tain the solution co nce ntration s for the sam ple, C s (µg/m L), an d the average m edia blank , C b (µg/m L), from the ins trum ent. 26. Us ing the solution volum es o f sam ple, V s (m L), an d m edia blank , V b (mL), calculate the concentration, C (µg/cm 2), of each element on the surface area sampled, S (cm 2):
EVALUATION OF METHOD: This method was evaluated using wipe media spiked with aqueous standards (fortified samples) and wipe m edia spiked with SRM 2711 (Montana Soil). Recoveries for the twenty-three elements listed on page 920 1-1 were within the range of 75-115% for the fortified samples. Ten of the eleme nts found in SR M 27 11 were recoverable within the same range. Th ese are: silver, arsenic, ca dm ium , co balt, co pper, m anganese, nicke l, pho sph orus , lead, and zinc .
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S O N W IPES: M ETH OD 9102, Issue 1, dated 1 5 Ma rch 2003 - Page 4 of 5 Be cause this m eth od is a simultaneous elemental analysis, it is not compound specific. The data provided is for those com pounds com patible with the acids used in the digestion . Ve rificatio n of the solubility of specific compounds of interest should be com pleted and the sam ple m atrix carefully exam ined. F or exam ple, if silicates are pre sent to tal elem ental values will not be m easured witho ut th e use of h ydrofluoric acid in the digestion process.
REFERENCES: [1] NIOSH [1994]. Elements by ICP, Method 7300 in: Eller PM, Cassinelli ME, eds. NIOSH M anual of An alytic al M eth ods, 4 th ed., C incinnati, O H: U.S. De partm ent of He alth and H um an Servic es, Pu blic He alth Service, Cente rs for Diseas e Contro l and P reve ntion, N ationa l Institute fo r Occu pation al Safety & H ealth. D HH S (N IOS H) P ublica tion N o. 94-113 . [2] AS TM [2002]. Annual Book of A ST M Sta ndards, Standard Specificatio n fo r W ipe Sam pling M ate rials for Lead in Surface Dust. W est Conshohocken, PA: ASTM International, E 1792-01. [3] ASTM [2002]. Annual Book of ASTM Standards, Standard Practice for Field Collection of Settled Dust Sam ples Using W ipe Sampling Methods for Lead Determination by Atomic Spectrometry Techniques. W est Conshohocken, PA: ASTM International, E 1728-99.
METHOD WRITTEN BY: Ronnee N. Andrews, Mark Millson, and Donald D. Dollberg, NIOSH/DART
TABLE 1. PROPERTIES Elem ent (Sym bo l)
Atomic Weight
MP (° C)
CAS #
RTECS
Silver (Ag)
107.87
961
7440-22-4
VW3675000
Arsenic (As)
74.92
817
7440-38-2
CG0525000
Barium (Ba)
137.33
725
7440-39-3
CQ8370000
Beryllium (Be)
9.01
1287
7440-41-7
DS1750000
Cadmium (Cd)
112.41
321
7440-43-9
EU9800000
Cobalt (Co)
58.93
1493
7440-48-4
GF8750000
Chromium (Cr)
52.00
1900
7440-47-3
GB4200000
Copper (Cu)
63.54
1083
7440-50-8
GL5325000
Iron (Fe)
55.85
1535
7439-89-6
NO4565500
Lanthanum (La)
138.91
920
7439-91-0
Manganese (Mn)
54.94
1244
7439-96-5
OO9275000
Molybdenum (Mo)
95.94
2622
7439-98-7
QA4680000
Nickel (Ni)
58.69
1555
7440-02-0
QR5950000
Phosphorus (P)
30.97
44
7723-14-0
TH3495000
Lead (Pb)
207.2
328
7439-92-1
OF7525000
Selenium (Se)
78.96
217
7782-49-2
VS7700000
Strontium (Sr)
87.62
769
7440-24-6
WK7849000
Tellurium (Te)
127.60
450
13494-80-9
WY2625000
Thallium (Tl)
204.38
304
7440-28-0
XG3425000
Vanadium (V)
50.94
1917
7440-62-2
YW1355000
Yttrium (Y)
88.91
1509
7440-65-5
ZG2980000
Zinc (Zn)
65.39
420
7440-66-6
ZG8600000
Zirconium (Zr)
91.22
1857
7440-67-7
ZH7070000
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition ELEM ENT S O N W IPES: M ETH OD 9102, Issue 1, dated 1 5 Ma rch 2003 - Page 5 of 5
TABLE 2. WAVELENGTH, LIMITS OF DETECTION (LOD), RANGE & PRECISION W avelen gth (nm )
Instrumental LOD (µg/wipe)
Range (µg/wipe)
Precision* (S r)
Silver (Ag)
328
0.035
0.11 8-25 .0
0.0701
Arsenic (As)
189
0.078
0.261-105.
0.0549
Barium (Ba)
455
0.010
0.03 33-1 0.0
0.0370
Beryllium (Be)
313
0.010
0.03 33-1 0.0
0.0267
Cadm ium (Cd)
226
0.010
0.03 33-4 1.7
0.0273
Cobalt (Co)
228
0.010
0.03 33-1 0.0
0.0301
Chrom ium (C r)
267
0.010
0.03 33-1 0.0
0.0287
Copper (Cu)
324
0.042
0.141-114.
0.0317
Iron (Fe)
259
0.074
0.24 6-50 .0
0.0516
Lanthanum (La)
408
0.018
0.05 93-2 5.0
0.0279
Manganese (Mn)
257
0.010
0.0333-638.
0.0333
Molybdemum (Mo)
202
0.010
0.03 33-1 0.0
0.0441
Nick el (N i)
231
0.010
0.03 40-2 0.6
0.0629
Phosphorus (P)
178
0.043
0.142-860.
0.128
Lead (Pb)
168
0.042
0.141-1160
0.0267
Selenium (Se)
196
0.10
0.33 8-75 .0
0.0364
Strontium (S r)
407
0.010
0.03 33-1 0.0
0.0368
Tellurium (Te)
214
0.047
0.15 6-50 .0
0.0359
Thallium (Tl)
190
0.041
0.13 6-50 .0
0.0256
Vanadium (V)
292
0.010
0.03 33-2 5.0
0.0284
Yttrium (Y)
371
0.010
0.03 33-1 0.0
0.0280
Zinc (Zn)
213
0.77
2.56-350.
0.101
Zirconium (Zr)
339
0.026
0.08 77-1 0.0
0.344
Elem ent (Sym bo l)
- Values were obtained with a Spectro ICP-AES; LOD may vary with instrument and should be
independently verified.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition