Research On The Rapid Detection Of Pesticide Residues In Food

Surface-enhanced Raman scattering (SERS) can greatly enhance the Ramansignal intensity, achieve single-molecule detection, and a simple sample pre-treatmentcharacteristics of high sensitivity, no damage, in recent years has begun to be used infood safety testing research.Organophosphorus pesticides is one of the common typesof pesticides, due to its good insecticidal effect, heavily used, but highly toxic. Ifresidues exceeding in vegetables and fruit’s surface, will do great harm to people.Thepapers collected two sets of experimental samples of the SERS, the first group aredimethoate, phorate, phosalone, fenthion, triazophos sprayed on cucumber, spinach,cabbage, greengrocery, cole’s surface, as well asmethamidophos, fenitrothion andparathion mixed, spraying in lettuce’s surface; the second group are three differentconcentrations (0.5mg/kg,1mg/kg,2mg/kg) phorate and fenthion solution, sprayingonto the apple’s surface.Qualitative analysis and quantitative analysis. SERS of the firstset of samples at Raman shift of510cm-1and690cm-1,754cm-1,1052cm-1,1221cm-1,1372cm-1,1408cm-1,1536cm-1, the Raman peaks of pesticides areobvious. These positions of the Raman frequency shift is by S=S stretching vibration,P=S stretching vibration, a benzene ring stretching vibration, ortho disubstitutedbenzene stretching vibration, bit disubstituted benzene stretching vibration, triazolering stretching. Fully explain the existence of a variety of organophosphorus pesticidesin the first group of samples.In methamidophos, fenitrothion and parathion mixedspectrum, at the peak of676cm-1,830cm-1,856cm-1is also a good illustration oftheir existence, prove the detection technology for the validity of mixed landmarkpesticides instructions.The second group of samples of three different concentrations ofphorate, fenthion solution selected728cm-1,1215cm-1to a target peak, water’s Ramanpeak of3200cm-1is a reference peak, study the relationship between their ratio andthe concentration, after the Origin software linear fit linear regression equation, regression coefficient that has a good linear relationship, both can as the calculation ofthe mathematical model of phorate and fenthion.Compared with traditional detectionmethods, the method has a microscopic trace, fast, simple, non-contact injury, easy ofscreening and dynamic monitoring detection characteristics of the direction of thedevelopment of food safety testing.