STRYCHNINE: METHOD 5016, Issue 2, dated 15 August 1994 - Page 3 of 3 a. b. c.
8.
Deposit a known amount of calibration stock solution onto the filter. Allow filters to air dry. Store samples overnight in ointment jars. Prepare for analysis (steps 3 through 5) and analyze together with working standards (steps 9 through 11). d. Prepare a graph of R vs. µg strychnine recovered. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and R graph are in control
MEASUREMENT: 9. 10. 11.
Set HPLC system according to manufacturer's recommendations and to the conditions given on page 5016-1. Inject sample aliquot using syringe, fixed volume sample loop or autosampler. Measure peak area.
CALCULATIONS: 12. 13.
Determine the mass, µg (corrected for R) of strychnine found in the sample (W) and in the average media blank (B) from the calibration graph. Calculate concentration, C, of strychnine in the air volume sampled, V (L):
EVALUATION OF METHOD: Method S302 was issued on February 17, 1978 [2], and evaluated over the range 0.073 to 0.34 mg/m using a 180-L sample [1,5]. Overall precision, SˆrT, was 0.059 with an average recovery of 100.9%, representing a non-significant bias. The concentration of strychnine was independently verified by analysis of filter samples with a UV spectrophotometer at 254 nm. Recovery was 0.98 in the range of 13.5 to 54.1 µg per sample. Collection efficiency was determined to be at least 98.8% for 180-L sample at a concentration to be 0.15 µg/mL. Average recovery for one-day old samples was 105% vs. 98.8% for seven-day old samples stored at room temperature. Since the filter samples for the recovery and stability studies were prepared with strychnine acetate rather than the free base, the recovery of the free base and the stability of such samples is unknown. REFERENCES: [1] [2] [3]
[4]
[5]
Back-up Data Report for Strychnine, NIOSH Contract No. 210-76-0123, available as "Ten NIOSH analytical Methods," Order Nol PB288-629 from NTIS, Springfield, VA 22161. NIOSH Manual of Analytical Methods, 2nd ed., Vol. 5, S302, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 79-141 (1979). Criteria for a Recommended Standard...Occupational Exposure During the Manufacture and Formulation of Pesticides, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 78-174 (1978), available as PB81-227001 from NTIS, Springfield, VA 22161. NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards, U.S. Department of health and Human Services, Publ. (NIOSH) 81-123 (1981), available as GPO Stock #017-033-00337-8 from Superintendent of Documents, Washington, D.C. 20402. NIOSH Research Report - Development and Validation of Methods for Sampling and analysis of Workplace and Toxic Substances, U.S. Department of Health and Human Services, Publ. (NIOSH) 80-133 (1980).
METHOD REVISED BY: M.J. Seymour, NIOSH/DPSE. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
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