A sampling and analytical method for the simultaneous determination of multiple organophosphorus pesticides in air.
Kennedy-ER; Abell-MT; Reynolds-J; Wickman-D
Am Ind Hyg Assoc J 1994 Dec; 55(12):1172-1177
An analytical procedure for simultaneously determining mixtures of organophosphate pesticides in air was developed. The method was developed using a mixture of 19 organophosphate pesticides. Simulated air sampling was performed by spiking the quartz filters of an XAD-2 sorbent sampler with solutions containing 0.2 to 360 micrograms per milliliter (microg/ml) of the pesticides inside an environmental chamber maintained at 10 to 50 degrees-C and 10 to 90% relative humidity (RH). After sampling, the filter and sorbent bed were desorbed with a 10:90 acetone/toluene mixture and the desorbates were ultrasonicated for 30 minutes. Tributyl-phosphate was added as an internal standard to the samples before ultrasonication. A portion of the sample was injected into a gas chromatograph fitted with a flame photometric detector for analysis. The detection limits of the pesticides ranged from 0.02 to 0.3microg/ml. The limits of quantitation varied from 0.07 to 1.0microg/ml. The average bias in the determinations varied from - 1.8 to -7.0%. Desorption efficiencies of the compounds were 97% or greater. Experiments examining the effects of temperature and RH on analyte recovery indicated that exposure at 10 and 30 degrees and 15 and 80% RH did not significantly affect recovery except in the case of methamidophos (10265926) and disulfoton (298044) which had recoveries of 68 and 88%, respectively, at 30 degrees and 15% RH. These environmental conditions, 30 degrees and 15% RH, were taken as the worst case sampling scenario. Storage of samples at ambient temperature or -5 degrees for 30 days did not result in any loss of analyte. The authors conclude that organophosphate pesticides can be simultaneously determined using a single analytical method with an accuracy of +/-25%.
NIOSH-Author; Analytical-methods; Air-sampling; Organo-phosphorus-pesticides; Solvent-extraction; Gas-chromatography; Air-sampling-techniques
American Industrial Hygiene Association Journal