A novel dispersive micro-solid phase extraction method combined with gas chromatography for analysis of organochlorine pesticides in aqueous samples

A novel dispersive micro-solid phase extraction (D-mu-SPE) method is presented in this paper. The most attractive feature of this method is taking full advantage of a plastic dropper and nanoscale one-dimensional polyaniline (1D-PANI). The plastic dropper was employed as both the extraction and preconcentration device. All procedures needed in the common mu-SPE were performed in a plastic dropper without any additional devices, such as a centrifuge, magnetic field and pressure blowing concentrator. So the operating steps were simplified greatly. 1D-PANIs were used as the sorbent. The huge surface and interconnected network structure of 1D-PANIs endows them with high dispersive adsorbability and good permeability for the adsorbed analytes to be eluted. To test the feasibility of the proposed method, eight organochlorine pesticides (OCPs) were selected as the model analytes for D-mu-SPE of OCPs in water samples. A series of extraction parameters have been investigated systematically. Under optimized conditions, the method showed that the linear correlation coefficients (r) were better than 0.9971 and the limits of detection (LODs) for eight OCPs ranged from 0.0121 to 0.0468 mu g L-1. The intra-and inter-day relative standard deviations (RSDs) were less than 11.9%. The recoveries of OCPs for three spiked aqueous samples ranged from 73.6 to 107.0%. The novel D-mu-SPE is promising to be an alternative sample preparation method for extracting apolar analytes in complex sample matrices because of its simplicity, low cost and high extraction efficiency.