: The Rapid Detection Methods Of Illegal Pigment And Organophosphorus Pesticide Residues In Food Using Surface Enhanced Raman Spectrum(SERS)

In recent years,food safety problems become increasingly serious.The toxic and harmful substances in food have threaten people’s physical heath.In view of this,more and more researches are being conducted to explore the methods of fast detection of the illegal additives in food.This study aims at testing the illegal pigment and organophosphorus Pesticide residues added into food with a combined method of Surface-enhanced Raman spectroscopy(SERS)and solid phase extraction(SPE).Three compounds selected from the two types of compounds respectively were measured through a serious of detection including qualitative and quantitative detection.The research on the six compounds are expected to provide important technical reference for the qualitative and quantitative analysis of the same kind of food additives.The yellow pigment including Basic Orange 2,Basic Orange 21,Basic Orange 22 were chosen as the targets.They were detected qualitatively and quantitatively based on the technology of SPE.To verify the effectiveness of the method,High performance liquid chromatofraphy(HPLC),a national standard technique of Basic orange was utilized.Under the same conditions,the recovery rate of SERS ranged from 84.5% to 101.3% in three standard addition concentrations of 2μg/mL,5μg/m L,10μg/mL,,with RSD from 2.6% to 9.6%,and the standard addition recovery rate of HPLC ranges from 95.4% to 101.2% with RSD from 1.2% to 3.4%.Three kinds of organophosphorus pesticides were chosen.They were triazophos,parathion and Fonofos.QuEChERS(Quick,Easy,Cheap,Effective,Rugged & Safe)technique was used for the practical sample pretreatment and then combined with SERS detection,forming a set of SOP methods.The recovery rate range was 85.5%~99.7% for three standard addition concentrations of 2 μg/mL,5 μg/mL,10 μg/mL with RSD from 3.6% to 9.8%.In order to verify the reliability of this rapid analysis method,national standard testing methods including GC-MS and LC-MS was used.The results showed that the spiked recovery rate of GC-MS range from 95.3% to 101.5% with RSD from 1.0% to 2.9%,and the spiked recovery rate of LC-MS range from 94.8% to 102.2% with RSD from 2.0% to 6.6%,which are similar to the SOP methods.Therefore,this method can also be used for the quantitative analysis of other kind of pesticide residues.For the detection of multi components,two components which randomly consist of different kinds of basic orange pigments were studied by SERS.The results showed that the different substances can be recognized by each characteristic peaks in the SERS spectra.On the other hand,this may have more practical significance for the detection of mixed pesticides used in agricultural products.We choose the widely used mixture type pesticide,dursban,mixed with parathion respectively,thus composing bi-component system for the detection.The results showed that effective identification can be realized by each characteristic peaks from each pesticide molecules.These experimental results finally show that surface-enhanced Raman spectroscopy has great potential in the detection of multiple chemical components.