Determination Of Organophosphorus And Organochlprine Pesticide Residues Using Gas Chromatography-Mass Spectrometry

In this paper, cigarette filter was used the adsorbent of solid-phase extraction (SPE), and the adsorbent capability for organophosphorus and organochlorine pesticides were studied. A new analytical technology using solid-phase extraction (SPE) with cigarette filter followed by gas chromatography-mass spectrometry (GC-MS) was developed. The results showed that cigarette filter has good adsorption ability for organophosphorus and organochlorine pesticides in the environmental sample. Parameters mainly influencing the extraction efficiency, such as the sample loading flow rate, eluent, and elution volume were optimized through Single factor experiment variables. The optimal operating conditions of SPE were that the sample loading rate was3mL min"1, the eluent was ethyl acetate with the volume of6mL. Furthermore, the separation and detection conditions of GC-MS for14pesticides were optimised through adjusting the injection volume, split ratio, MS detection mode and temperature programmed, et al. The optimal GC-MS conditions were as follows: the injection volume was1μL, injection mode was splitless, the detect mode of MS was SIM and temperature programmed was that initial temperature140℃, increased to160℃at a rate of20℃min-1, then increased to200℃at a rate of7℃min-1and held for2min, afterwards increased to230℃at8℃min-1and held for2min, and then increased to290℃at9℃min-1, and held for5min.The features of the developed method were investigated by add experiment of Blank water and soil samples, and the result show that good linearity was obtained for all the14pesticides (r2>0.99) over the range of0.1-20μg L-1and2-400μg Kg-1for water and soil samples, respectively. The mean recoveries were in the range of76.4-103.7%for water samples and79.9%-105.3%for soil samples with the precisions (RSD) were3.2%-13.6%and0.91%-12.7%. The detection limits (S/N=3) of the proposed method were ranged from0.01-0.20μg L-1for water samples and0.42-6.95μg Kg-1for soil samples.Based on the developed method, comparison of adsorption effect for cigarette filter and C18were studied. The results showed that the two adsorbents gave similar recoveries (>70%) for most of pesticides. However, the chromatograms of the samples showed that the extracts pretreated by cigarette filter SPE were cleaner than those pretreated by using C18SPE.The developed method was applied to the analysis of real samples. Furthermore, the spiked blank soil sample and spiked blank water sample were also analyzed, and the result was satisfactory.