Page:NIOSH Manual of Analytical Methods - 5002.pdf/3



  Allow the filters to air dry overnight. Analyze the filters (steps 3, 4, 6 and 7). Prepare a graph of recovery vs. µg of Warfarin recovered.  

MEASUREMENT: Set liquid chromatograph according to manufacturer's recommendations and to conditions given on page 5002-1. Make duplicate injections of each sample and working standard. Measure peak area.  CALCULATIONS: <li>Read the mass, µg (corrected for recovery) corresponding to the sample peak area of the sample (W) and average media blank (B) from the calibration graph.</li> <li>Calculate the concentration, C (mg/m3), of Warfarin in the volume of air sampled, V (L):</li> </ol>

EVALUATION OF METHOD:

Method P&CAM 313 was issued on April 13, 1979 &lsqb;2&rsqb;. Lab testing was done with spiked samples and atmospheres dynamically generated by Wright dust feeder from commercial formulation; no adequate independent method was used for verification &lsqb;1, 5&rsqb;. Storage stability was 93.5% for 60-µg samples stored seven days at ambient conditions. Collection efficiency = 100% for 408-L samples at 0.24 mg/m 3; no evidence of vapor in Tenax backup. Precision was as given on page 5002-1.

REFERENCES: <ol style="list-style-type:none;"> <li> &lsqb;1&rsqb; Backup Data Report, P&CAM 313, prepared under NIOSH Contract 210-76-0123 (unpublished, April, 1979).</li> <li> &lsqb;2&rsqb; NIOSH Manual of Analytical Methods, 2nd. ed., V. 6, P&CAM 313, U.S. Department of Health and Human Services, Publ. (NIOSH) 80-125 (1980).</li> <li> [3] Horwitz, W., Ed. Official Methods for Analysis of the AOAC, 13th ed. , p. 85 (1980).</li> <li> [4] Ibid, 628.</li> <li> &lsqb;5&rsqb; NIOSH Research Report-Development and Validation of Methods for Sampling and Analysis of Workplace Toxic Substances, U.S. Department of Health and Human Services, Publ. (NIOSH) 80-133 (1980).</li> </ol> METHOD REVISED BY:

James E. Arnold, NIOSH/DPSE; P&CAM 313 developed under NIOSH Contract 210-76-0123.