Page:NIOSH Manual of Analytical Methods - 7300.pdf/3

 ELEM ENT S (ICP): ME TH OD 7300, Issue 3, dated 1 5 March 2003 - Page 3 of 8 CALIBRATION AND QUALITY CONTRO L: 12. Calibrate the spectrometer according to the manufacturers recomm endations. NOTE: Typically, an acid blank and 1.0 µg/m L m ultielem ent w ork ing sta nda rds are u sed. The following multielement combinations are chemically compatible in 4% HNO 3/1% HC lO 4: 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 blank filters per ten samples.

MEASUREMENT: 15. Set spec trome ter to conditions spe cified by manufac turer. 16. Analyze standards and samples. NOTE: If the values for the sam ples are a bove the rang e of th e standa rds, dilute the solutions w ith dilution acid, reanalyze and apply the appropriate dilution factor in the calculations.

CALCULATIONS: 17. Obta in the solution con cen trations 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. 18. Using the solution volum es o f 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):

NOTE: µg/L / m g/m 3

EVALUATION OF METHOD: Issues 1 and 2 Method, 7300 was originally evaluated in 1981 [2,3]. The precision and recovery data were determined at 2.5 and 1000 µg of each element per sample on spiked filters. The m easurements used for the method evaluation in Issues 1 and 2 were determined with a Jarrell-Ash Model 1160 Inductively Coupled Plasma Spectrometer operated according to manufacturer's instructions. Issue 3 In this update of NIOSH Method 7300, the precision and recovery data were determined at approximately 3x and 10x the instrumental detection limits on comm ercially prepared spiked filters [12] using 25.0 mL as the final sample volume. Tables 3 and 4 list the precision and recovery data, instrumental detection limits, and analytical wavelengths for m ixed cellulos e es ter (M CE ) and polyvinyl chloride (P VC ) filters. PVC Filters which can be used for total dust measurem ents and then digested for m etals m eas urem ents were tested and found to give good results. The values in Tables 3 and 4 were determined with a Spectro Analytical Instruments Model End On Plasma (EOP)(axial) operated according to manufacturer’s instructions.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition