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

ABSTRACT

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 microm PDMS and 85 microm PA, were compared and 85 microm 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 microg L(-1) for most of the OPPs. The limits of detection (LODs) ranged from 0.01 microg L(-1) (for bromophos-ethyl) to 55 microg 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 microm 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).