POLYCHLOROBENZENES: METHOD 5517, Issue 2, dated 15 August 1994 - Page 4 of 5
P&CAM 343 was issued on August 31, 1981 [2]. A two-stage sampler was tested using 10- to 12-L samples at 28 to 30 °C and >80% RH over the ranges 0.002 to 100 mg/m 3 for 1,2,4-trichlorobenzene, 0.003 to 31 mg/m 3 for 1,2,4,5-tetrachlorobenzene, and 0.008 to 22 mg/m 3 for pentachlorobenzene for this issue of Method 5517 [1,2]. The average recoveries were 0.957 for 1,2,4-trichlorobenzene, 1.014 for 1,2,4,5-tetrachlorobenzene, and 0.968 for pentachlorobenzene, with concentrations independently verified by collection in impingers. These biases were insignificant at a 0.05 significance level. For levels of 0.02, 0.1, 0.4, 0.5, 25, and 500 µg per sample, the average desorption efficiencies were 0.908 for 1,2,4-trichlorobenzene, 0.901 for 1,2,4,5-tetrachlorobenzene, and 0.917 for pentachlorobenzene. At 25 µg, only pentachlorobenzene was observed in significant amounts on the filter and holder (4.7% of the total amount recovered). However, at 500 µg, the average contribution from the filter and holder to the totals were 7.2% for 1,2,4-trichlorobenzene, 55.2% for 1,2,4,5-tetrachlorobenzene, and 67.9% for pentachlorobenzene. The use of polypropylene filter holders was rejected because even at the 500-ng level, polypropylene filter holders retained 14% of the 1,2,4-trichlorobenzene, 34% of the 1,2,4,5-tetrachlorobenzene, and 45% of the pentachlorobenzene. After storage for several days, this might not be recoverable. Polystyrene holders did not appear to retain chlorobenzenes, but were not available in the 13-mm size. The capacity of the 100-mg sorbent section for 1,2,4-trichlorobenzene, the most volatile of the analytes, was 24 L for a concentration of 45 mg/m 3 at 40 °C and >80% RH. The test atmosphere also contained 1,2,4,5-tetrachlorobenzene at 22 mg/m 3 and pentachlorobenzene at 15 mg/m 3. Capacities for the latter two analytes were not specifically determined, but were greater than 24 L. A storage stability study found no significant losses after 13-day storage in the dark at room temperature for 2.5-L samples containing 35 ng 1,2,4-trichlorobenzene, 63 ng 1,2,4,5-tetrachlorobenzene, and 43 ng pentachlorobenzene. The configuration of the two-stage sampler has been simplified.
REFERENCES: [1]
[2]
Dillon, H. K., and M. L. Bryant. Analytical Methods Evaluation and Validation for 1,2,4-Trichlorobenzene; 1,2,4,5-Tetrachlorobenzene; Pentachlorobenzene; and Polychlorinated Terphenyls: Research Report for 1,2,4-Trichlorobenzene; 1,2,4,5-Tetrachlorobenzene; Pentachlorobenzene, NIOSH Contract No. 210-79-0102, Southern Research Institute, Birmingham, AL (1981). NIOSH Manual of Analytical Methods, 2nd ed., V. 7, P&CAM 343, U.S. Department of Health and Human Services, Publ. (NIOSH) 82-100 (1982).
METHOD REVISED BY: R. Alan Lunsford, Ph.D., NIOSH/DPSE; data obtained under NIOSH Contract 210-79-0102.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
