Page:NIOSH Manual of Analytical Methods - 1500.pdf/4

 HYD RO CAR BO NS, BP 36-216 °C : MET HO D 150 0, Issue 3, dated 15 M arch 200 3 -Page 4 of 8 EVALUATION OF METHOD: Issues 1 and 2: Precisions and biases (Table 3) were determ ined by analyzing generated atm osphe res containing one-ha lf, one, and two times the OSHA standard. Table 3 does not contain data for n-decane, n-dodecane and nheptane since they were not evaluated previously. Generated concentrations were independently verified. Breakthrough cap acities were de term ined in dry air. Storage stability was assessed at 7, 14, and 30 days. Measurement precisions (Table 4) were determined by spiking sampling media with amounts corresponding to one-half, one, and two times the OSH A standard for nominal air volumes. Desorption efficiencies for spiked sam plers con taining only one co m pou nd e xce ede d 75 % [2,3,4,8 ]. Issue 3: The desorption efficiency, at levels ranging from 10 times the LOQ to 0.1 times the REL, was determined by spiking known am oun ts of analytes (in CS 2) on coconut shell charcoal tubes. All analytes exhibited accepta ble desorption efficiency recovery results at six levels evaluated. Each analyte was evaluated for its storage stability. Sorbent tubes were spiked at approximately 100 µg and stored in a drawer for 7 days, then transferred to a refrigerator at 5° C. Samples were analyzed after 7, 14, and 30 days. A ll analyte s had accepta ble rec overies (>9 0% ), except cyc lohexene, which had a 30 day recovery of 85% [1].

REFERENCES: [1] Pende rgrass SM and M ay L, Backup Data R eport, ACS /CEM B/DAR T/NIO SH (19 99). [2] NIOSH[1994]. Hydrocarbons, BP 36-136°C. In: Eller PM, ed. NIOSH M anual of Analytical Methods, 4th rev. ed. Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, DHHS (NIOSH) Publication No. 94-113. [3] NIOSH M anual of Analytical Methods, 2nd. ed., V. 2, S28, S82, S89, S90, S94, U.S. Department of Health, Educa tion, and W elfare, Publ. (NIOSH ) 77-157-B (19 77). [4] NIOSH M anual of Analytical Methods, 2nd. ed., V. 3., S378, S379, U.S. Department of Health, Educa tion, and W elfare, Publ. (NIOSH ) 77-157-C (1977). [5] Code of Federal Regulations; Title 29 (Labor), Parts 1900 to 1910; U.S. Government Printing Office, W ashington, (1989); 29 CFR 1910.1000. [6] NIOSH Recom mendations for Occupational Safety and Health. U.S. Department of Health and Hum an Services, D HH S (NIO SH) P ublication No. 92-100 (1992 ). [7] 1993 T hreshold Lim it Values for Chem ical Substances and Physical Agents an d Biological Exposure Indices. ACG IH, Cincinnati, OH (1993). [8] Documentation of the NIOSH Validation Tests, S28, S82, S89, S90, S94, S378, S379, U.S. Depa rtmen t of Health, Education, and W elfare, Publ. (NIOSH ) 77-185 (197 7).

AUTHORS: Issues 1 and 2: R. Alan Lunsford, Ph.D., NIOSH/DPSE Issue 3: Stephanie M. Pendergrass, NIOSH/DART and Leroy R. May, NIOSH/PRL

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition