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 MONOMETHYLANILINE: METHOD 3511, Issue 1, dated 15 August 1994 - Page 3 of 3 d.

12.

Neutralize following step 8 and analyze along with working standards and blanks (steps 13 through 15). e. Prepare graph of recovery vs. µg monamethylaniline. Analyze three quality control spikes and three analyst spikes to ensure that calibration graph and recovery graph are in control.

MEASUREMENT: 13. 14.

15.

Set gas chromatograph according to manufacturer's recommendations and to conditions given page 3511-1. Inject 5-µL sample aliquot. NOTE: If peak area is above the linear range of the working standards, dilute, reanalyze, and apply appropriate dilution factor in calculations. Measure peak area.

CALCULATIONS: 16. 17.

Determine mass, µg (corrected for recovery), of monomethylaniline (W) found in the sample and the average media blank. Calculate concentration of monomethylaniline in the air volume sampled V (L):

EVALUATION OF METHOD: This method was evaluated over the range 4.38 to 17.52 mg/m 3 using 100-L samples [1,2]. Overall sampling and measurement precision, SˆrT, was 0.089, with essentially 100% recovery, representing a non-significant bias. Sample stability during storage was evaluated at 791 µg n-methylaniline per sample. Samples showed 98.3% recovery after seven days of storage.

REFERENCES: [1] [2] [3] [4]

Backup Data Report for n-methylaniline, Documentation of NIOSH Validation Tests. U.S. Department of Health, Education, and Welfare, (NIOSH) Publication 77-185 (April, 1977). NIOSH Manual of Analytical Methods, 2nd. ed., V. 3, S153, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 78-175 (1978). Hawley's Condensed Chemical Dictionary, 11th ed. Sax, N.I. and Lewis, R.J., Eds. Van Nostrand Reinhold Co., New York, NY (1987). NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, US DHHS (NIOSH) Publ. 81-123 (1981).

METHOD REVISED BY: Paula Fey O'Connor, NIOSH/DPSE.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94