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 DIBUTYL PHTHALATE and DI(2-ETHYLHEXYL) PHTHALATE: METHOD 5020, Issue 2, dated 15 August 1992 - Page 3 of 4

to air dry. Store samples overnight in cassettes. Prepare for analysis (steps 5 through 7) and analyze together with working standards (steps 11 and 12). d. Prepare a graph of R vs. mg analyte recovered. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and recovery graph are in control. b. c.

10.

MEASUREMENT: 11.

12.

Set gas chromatograph according to manufacturer's recommendations and to conditions on page 5020-1. Inject sample manually using solvent flush technique or with autosampler. NOTE: If peak area is above the linear range of the working standards, dilute with eluent, reanalyze, and apply the appropriate dilution factor in calculations. Measure peak area. Divide the peak area of analyte by the peak area of internal standard on the same chromatogram.

CALCULATIONS: 13. 14.

Determine the mass, mg (corrected for recovery) of analyte found on the filter (W) and in the average media blank (B). Calculate concentration, C, of analyte in the air volume sampled, V(L):

EVALUATION OF METHOD: Methods S33 (dibutyl phthalate) [3] and S40 [di(2-ethylhexyl) phthalate] [4] were issued on January 17, 1975 and validated over the range 2 to 10 mg/m 3 at 23° and 25 °C and 767 mm and 761 mm Hg, respectively, using 30- and 32-L air samples [1,2]. Test atmospheres of the phthalates were generated using a Royco generator/impinger system and calibrated using the GC assay procedure. Overall precision, s r, was 0.057 for both compounds with average recoveries for generated samples of 94 and 107%, respectively. Extraction efficiencies were 97 and 96% in the range 0.07 to 0.30 mg per sample. Collection efficiency for aerosols (less than 5 mm) on this type filter was greater than 99.9%.

REFERENCES: [1] Documentation of NIOSH Validation Tests, S33, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977), available as GPO Stock #017-033-00231-2 from Superintendent of Documents, Washington, DC 20402. [2] Ibid., S40. [3] NIOSH Manual of Analytical Methods, 2nd ed., Vol. 2, S33, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977). [4] Ibid., S40.

METHOD WRITTEN BY:

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/92