HPLC Detects Organophosphorous Pesticides In Water

Organophosphorus pesticides belong to POPs,They will be present in the environment in the long term,They have serious impact on human health by food chain.Most organophosphorus pesticides belong to hazardous substances,They persist in the environment in daily life.They enters the body through the skin,the digestive tract and respiratory tract and damage the health of human body light or heavily.Not only do organophosphorus pesticide residues affect People's daily lives and health,agricultural and industrial waste water emissions will also have serious impact on the ecological environment.Due to the further acquaintance about the environmental pollution problem,Organophosphorus pesticide problems become the focus of attention problems.So,we need to develop a method of the system to detect the organophosphorus pesticides in environmental water rapid,accurately and effectively.By now,the means of research methods about organophosphorus pesticides are generally included:GC,HPLC,GC-MS,HPLC-MS.High Performance Liquid Chromatography(HPLC)does not have chemistry action with the target compounds and it can be used for analysis materials which are difficult to volatilizeor polar strong.So HPLC has a unique advantage over testing and preparing organophosphorus pesticide.Thus I choose the method of using HPLC to analysis phosphorous pesticides in water.Widespread used organophosphorus pesticide are included:Dimethoate,Phorate,Chlorpyrifos,Monocrotophos,Methidathion,Phoxim,Phosphorus absorption and Methamidophos.I chose Dimethoate,Chlorpyrifos,Methamidophos,Methidathion for separation.In the meanwhile,optimize the temperature,wavelength,flow velocity and proportion of mobile phase to get the best chromatographic condition:methanol:water(60:40,V/V)as mobile phase,220 nm as the detection wavelength,the flow rate of 0.8 ml/min,temperature 30?,sample amount to 20 p.L.Each pesticide standard are linearly related only within a certain range,beyond this range,the measured results will not be accurate.So it is very important to find the linear range.Gradient dilution with four kinds of organophosphorus pesticide respectively,then analyze the sample.We need to draw the linear curve and obtain a linear regression equation.This experiment adopts the external standard method to analyze south lake water.Firstly,the peak area of four kinds of pesticides in the water is obtained by chromatographic,and then according to the linear regression equation,calculate the content of four kinds of organophosphorus pesticide.