Study On The Determination Method Of Organophosphorus Pesticides Residues In Vegetables

Organophosphorus pesticides are the most widely used in our country,residues invegetabals can do harm to people. In order to understand Huaian current status of pesticide residues in vegetables, gas chromatograph (GC), as a rapidly method to test seventeen organophosphorus pesticides resides, was founded.In this paper, according to the nature of organicphosphorus pesticide, with GC, simultaneous determination of17kinds of organophosphorus pesticides(Dichlorvos、 Methamidophos、 Acephate、 Phorate、 Omethoate、 Disulfoton、Monocrotophos、 Dimethoate、 Pirimiphos-methyl、 Chlorpyrifos、 Methyl parathion、 Malathion、Fenthion、 Parathion、 Methidathion、 G-line P、B parathion) in research methods.According to the different column, column temperature and flow rate selection, the optimal conditions of chromatographic separation was chosen as following:Agilent6890N GC, FPD, capillary column HP-1701, gasification chamber temperature150℃, detector temperature250℃,100℃(0.5min)-40℃/min-220℃(Omin)-5℃/min-240℃(8min), Hydrogen75ml/min, air100ml/min, carrier gas for high-purity nitrogen. Last blow0.7ml/min; split ratio10:1;.Column temperature control with temperature programming.Different methods of sample pre-treatment for determination were applied according to the different types of vegetables. Recovery of standard addition method with the related verification experiment.17kinds of pesticides standard curve were plotted, and the minimum concentration of the standard series were progressively diluted. Through the sample analysis, we obtained detection limits of all pesticides. Take two concentrations of standard solution in one day for five times were repeated measurements and determination of3days. With water spinach, celery, onions, green peppers, represented, respectively, we did the standard addition recovery experiment and calculated the recovery rate and precision.17kinds of organophosphorus pesticides in the column get a good separation, standard curve with good linearity, RSD was0.9985-0.9999and MOD was0.003-0.044mg/kg. Detection precision of standard solution RSD was0.3-2.4, and REC was91.1%-108.4%。Practice has proved that detection methods in this article, Pre-processing simple, measurement accuracy, reproducibility, linear range and the minimum detectable levels were suitable for organicphosphorus pesticide residues in vegetables at the same time were analyzed. This paper built a simultaneous determination of organophosphorus pesticide residues in vegetables by gas chromatography method, Implementation of17organophosphorus pesticides commonly fast, simple and accurately qualitative and quantitative analysis. And application of the method, the Huai’an vegetables sold over the past year conducted a sample survey, in order to understand the public consumption of organicphosphorus pesticide residues in vegetables and conditions, so as to provide a basis for developing countermeasures.