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p-NITROANILINE: METHOD 5033, Issue 1, dated 15 August 1994 - Page 3 of 3 10.

Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and recovery graph are in control.

MEASUREMENT: 11. 12.

13.

Set HPLC according to manufacturer's recommendations and to conditions on page 5033-1. Separation is achieved on a silica column using a mobile phase of 40% isopropanol/60% hexane at 1 mL/min. Inject 20-µL sample aliquot. NOTE: If peak area is above the linear range of the working standards, dilute with isopropanol and apply the appropriate dilution factor in calculations. Measure peak areas.

CALCULATIONS: 14. 15.

Determine the mass of p-nitroaniline, µg (corrected for recovery), for the sample (W) and average media blank (B). Calculate the concentration of p-nitroaniline, C (mg/m 3), in the air volume sampled, V (L):

EVALUATION OF METHOD: The method is not applicable to environments where p-nitroaniline vapor is present. However, experiments indicate that less than 0.04 mg/m 3 of p-nitroaniline would exist as a vapor at 40 °C [1]. Extraction efficiencies of spiked filters containing 0.278, 0.556, or 1.112 mg of p-nitroaniline were 96.6%, 94.7%, and 94.6%, respectively [1]. Samples generated to measure the filter's collection efficiency at 1.5 L/min for concentration of 3.9, 6.75, and 12.88 mg/m 3 showed recoveries of 95.9%, 98.8%, and 100.9% respectively [1]. The average recovery for 7-day-old samples was 98.6% [1].

REFERENCES: [1] [2] [3]

Back-up Data Report for p-Nitroaniline, S7, prepared under NIOSH Contract No. 210-76-0123, (1977). NIOSH Manual of Analytical Methods, 2nd ed., V 3, S7, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-B (1977). NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981), available as stock #PB 83-154609 from NTIS, Springfield, VA 22161.

METHOD REVISED BY: Charles Neumeister, NIOSH/DPSE.

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

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