A method for simultaneous determination of 14 pesticides (organochlorine and pyrethroid) in water was developed using the single drop microextraction (SDME) and gas chromatography with an electron capture detector. Experimental variables including organic solvent, volume of the microdrop, extraction time, volume and stirring speed of the sample and the addition of salt were evaluated to maximize the performance of the SDME technique. Coefficients of variation (CV) lower than 20% and relative recoveries between 71 and 107% indicated good precision and accuracy of the method. The developed protocol also showed selectivity and good linearity with correlation coefficients (r) greater than 0.99. Limits of detection of the analytes of interest were between 0.003 and 0.6 µg L-1, all below the respective maximum contaminant levels (MCL) for drinking water. Drinking water samples were analyzed using the proposed method and none of the pesticides were detected.
single drop microextraction; organochlorine; pyrethroid; gas chromatography; electron capture detector
