Study On Determination Of Organic Phosphorus Pesticide In Environmental Water By Flow Injection Spectrophotomentry

Organophosphorus pesticide is an efficient, rapid and broad-spectrum pesticide. However, most of the organic phosphorus pesticide has high toxicity. Being long-term heavy used can cause many potential hazards. Organophosphorus pesticide residued in environmental water is an escalating problem that has aroused public concern over potential health hazards. Conventional methods for detecting residual organophosphorus pesticides, including chromatography, mass spectrometry, spectroscopy, are time-consuming and costly. These methods can't meet the increasing requirements for the online detection of organophosphorus pesticides. A faster and online detection of organophosphorus pesticides based on the union of flow injection and spectrophotometry was developed.(1) An automatic, convenient method was developed for determining organic phosphorus pesticide in environment water. This method which was based on the inhibition effects of organic phosphorus pesticide to plant-esterase coupled flow injection technique perfectly. The optimized determining conditions were acquired, and the analytical characteristics of this method were studied. Under these optimum conditions, the linear range of dichlorvos' standard curves was 0.008-4.00mg/L. The linear equation of dichlorvos was U(mV) =-4874.4C(mg/L)+110313. The correlation coefficient of dichlorvos was 0.9984. The detection limit (S/N=3) was 0.02mg/L for dichlorvos. The relative standard deviation (RSD) of dichlorvos was 1.04%(n=6). The recoveries ranged from 95% to 105%. The results also indicated that the method developed in this study could be applied satisfactorily to determine trace dichlorvos in environment waters.(2) Most organophosphorus pesticides are Organophosphate substances, which can be hydrolied easily under the alkaline conditions. An automatic, convenient molybdenum-blue spectrophotometry method was developed for determining organic phosphorus pesticide in environment water. This method which was based on the study of alkaline hydrolysis condition of organic phosphorus pesticide coupled flow injection technique perfectly. Under these optimum conditions, the linear range of omethoate's standard curves was 0.004～1.60mg/L. The linear equation of omethoate was U(mV)=14.131 C(mg/L)+16.028. The correlation coefficient of omethoate was 0.9977. The detection limit (3S/K) was 0.082mg/L for omethoate. The relative standard deviation (RSD) of omethoate was 2.01%(n=6). The recoveries ranged from 95% to 105%. The linear range of chlorpyrifos standard curves was 0.04-1.60mg/L. The linear equation of chlorpyrifos was U(mV)=13.573C(mg/L)+49.093. The correlation coefficient of chlorpyrifos was 0.9988. The detection limit (3S/K) was 0.04mg/L for chlorpyrifos. The relative standard deviation (RSD) of chlorpyrifos was 2.01%(n=6). The recoveries ranged from 95% to 105%. The results also indicated that the method developed in this study could be applied satisfactorily to determine trace dichlorvos in environment waters.