CHLORINATED TERPHENYL (60% CHLORINE): METHOD 5014, Issue 2, dated 15 August 1994 - Page 3 of 3
8.
b. Desorb filters as in steps 3 through 5, and analyze as in steps 9 and 10. Check for possible contamination during shipment of field samples by comparing results from field blanks and media blanks.
MEASUREMENT: 9.
10.
Set gas chromatograph to conditions given on page 5014-1 and optimize detector performance per manufacturer's instructions. Using given conditions, retention time of largest and most distinct peak in cluster was about 6.1 min. Inject sample aliquot and measure detector response, e.g., height from base of cluster to top of most prominent peak.
CALCULATIONS: 11. 12.
Read the mass, µg, of chlorinated terphenyl found in each sample (W) and average media blank (B) from calibration graph. Calculate concentration, C (mg/m 3), of chlorinated terphenyl in the air volume sampled, V (L):
EVALUATION OF METHOD: Measurement precision was determined by analyzing spiked sampling media [1]. The average recovery was 1.006. There appeared to be no effect on recovery when up to 2700 L of charcoal-filtered air (40 °C and 40% relative humidity) was passed through filters spiked at the 1-µg level. Recoveries from 100-L samples collected from generated aerosol were 1.05 ( Sr = 0.162) after seven days storage, and 0.875 (Sr = 0.206) after 14 days storage, relative to the amount found after one day. Generated concentrations were not reproducible, and independent methods for determining the true concentration appeared to provide lower and more imprecise results than this method. Because of the difficulty in determining the true concentration, overall precision and bias were not determined. References [1] and [2] provide additional information.
REFERENCES: [1] Graham, M. M., and H. K. Dillon. Analytical Methods Evaluation and Validation for 1,2,4-Trichlorobenzene, 1,2,4,5-Tetrachlorobenzene, Pentachlorobenzene, and Polychlorinated Terphenyls: Research Report for Polychlorinated Terphenyls, NIOSH Contract No. 210-79-0102, Southern Research Institute, Birmingham, AL, available from NTIS (1982) as PB-83-140-087. [2] Kimbrough, R. D., ed. "Halogenated Biphenyls, Terphenyls, Naphthalenes, Dibenzodioxins and Related Products," Topics in Environmental Health, V. 4, Elsevier/North-Holland Biomedical Press, Amsterdam, 20-21 (1980).
METHOD WRITTEN 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
