Application of solid-phase microextraction for the determination of organophosphorus pesticides in textiles by gas chromatography with mass spectrometry

A method based on solid-phase microextraction (SPME) and gas chromatography with mass spectrometry (GC/MS) for the determination of 18 organophosphorus pesticides (OPPs) in textiles is described. Commercially available SPME fibers, 100 mu m PDMS and 85 mu m PA, were compared and 85 mu m PA exhibited better performance to the OPPs. Various parameters affecting SPME, including extraction and desorption time, extraction temperature, salinity and pH, were studied. The optimized conditions were: 35 min extraction at 25 degrees C, 5% NaSO4 content, pH 7.0, and 3.5 min desorption in GC injector port at 250 degrees C. The linear ranges of the SPME-GC/MS method were 0.1-500 mu g L-1 for most of the OPPs. The limits of detection (LODs) ranged from 0.01 mu g L-1 (for bromophos-ethyl) to 55 mu g L-1 (for azinphos-methyl) and the RSDs were between 0.66% and 9.22%. The optimized method was then used to analyze 18 OPPs in textile sample, and the determined recoveries were ranged from 76.7% to 126.8%. Moreover, the distribution coefficients of the OPPs between 85 mu m PA fiber and simulative sweat solution (K-pa/s) were determined. The determined K-pa/s of the OPPs correlated well with their octanol-water partition coefficients (r = 0.764 and 0.678) and water solubility (r = -0.892 and -0.863). (C) 2009 Elsevier B.V. All rights reserved.