Determination of carbamate pesticides using micro-solid-phase extraction combined with high-performance liquid chromatography

We describe a simple and sensitive porous polypropylene membrane-protected micro-solid-phase extraction (mu-SPE) approach for the sample preparation and determination of carbamate pesticides in soil samples by high-performance liquid chromatography. The mu-SPE device consisted of C-18 sorbent held within a porous polypropylene envelope. In order to achieve optimum performance, several extraction parameters were optimized. Under the most favorable conditions, the extraction efficiency of the mu-SPE was very high, with detection limits in the range of 0.01-0.40 ng g(-1). This is more than two orders of magnitude lower than the limits obtained by the United States Environmental Protection Agency Methods 8321 A and 8318. A linear relationship was obtained for each analyte in the range of 2 and 200 ngg(-1). The relative standard deviation for the analysis of aged soil samples spiked at 5 ngg(-1) was <= 11%. The reproductibility of separate mu-SPE device used for experiments was satisfactory (relative standard deviations ranged from 4 to 11%), indicating that the method is reliable for routine environmental analysis. (C) 2008 Elsevier B.V. All rights reserved.