Terahertz Map Scanning And Qualitative And Quantitative Detection Of Antibiotic-doped Feed

As an antibacterial drug,antibiotics provide protection for the health of livestock and poultry,but excessive use will lead to drug residues in livestock products,and then bring the risk of bacterial resistance and environmental pollution.Many countries have issued a series of anti-antibiotic measures to regulate the use of antibiotics.Existing antibiotic detection methods mainly include microbiology detection method,immunoassay method,etc.which mainly have the disadvantages of complex detection process,time-consuming,destructive and so on.The development of a fast and efficient detection method has become the demand of the industry.Based on the review of relevant research progress at home and abroad,this study started from feed,took pefloxacin and flurloxacin,typical quinolone antibiotics,as the research object,carried out qualitative and quantitative detection of these two antibiotics in feed with the help of terahertz spectroscopy combined with stoichiometry.Different kinds of antibiotics were identified by map fusion technique.The research contents and conclusions are as follows:(1)Study on spectral characteristics of different materials based on THz-TDS technology.Terahertz spectrum data of two antibiotics and two antibiotics mixed with fish meal feed at different concentrations of 3%,5%,10%,15%,20%,25%,30%,35%,40%,45%,50%,55%,60%,65%,70%,75% and 80% were obtained by terahertz spectrometer.And its spectral data are studied and analyzed.The following conclusions were drawn: pefloxacin had absorption peaks at 0.775 and 0.988 THz,flroxacin had absorption peaks at 0.919 and 1.088 THz.When the two target antibiotics were mixed with fish meal feed,the absorption peak still existed,and the absorption coefficient intensity at the absorption peak increased with the increase of concentration,indicating that it was suitable for further qualitative and quantitative analysis.(2)Qualitative identification of feed doping antibiotics based on THZ-TDS technology.The biclassification of pefloxacin-fish meal feed,flurloxacin-fish meal feed and the mixture of pefloxacin-fish meal feed,flurloxacin-fish meal feed and pefloxacinflurloxacin-fish meal feed were divided into three categories.When classified,each class of substances includes the different concentrations described in(1).First of all,principal component analysis(PCA)was used to cluster the two binary mixtures well.When ternary mixture was added,the ternary mixture would be incorrectly clustered to pefloxacin-fish meal feed and fluroxacin-fish meal feed.Then,support vector machine(SVM)and back propagation neural network(BPNN)were used to model and discriminate the absorption coefficient at the feature frequency selected by the successive projection algorithm(SPA),and the classification accuracy of SVM model reached 97.06%.The discriminant accuracy of SVM and BPNN was 71.57% and80.39%,respectively,when adding ternary mixture for three classifications.(3)Quantitative prediction of feed doping antibiotics based on THZ-TDS technology.Full spectral-partial least squares(PLS),SPA-BPNN,SPA-multiple linear regression(MLR),SPA-least squares support vector machine(LSSVM)regression model combined with absorption coefficient,frequency domain spectral data were used to determine the content of pefloxacin in pefloxacin-fish meal feed,pefloxacinfluroxacin-fish meal feed and the content of fluroxacin in fluroxacin-fish meal feed and fluroxacin-pefloxacin-fish meal feed was predicted.And the added content of the two antibiotics in fish meal feed was analyzed from the perspective of the existence of a single antibiotic and the coexistence of two antibiotics.The conclusions are as follows: When using different models to predict,the correlation coefficients between the predicted value and the actual value are all greater than 0.95,indicating that it is feasible to use terahertz spectrum technology for quantitative analysis of the two antibiotics in fish meal feed and simultaneous detection when multiple antibiotics coexist.(4)Identification of different types of samples based on terahertz spectrum fusion technology.Through imaging the maximum frequency difference data of the frequency domain spectrum of pefloxacin,fluroxacin,fish meal feed and polyethylene,it can be found that the maximum difference of the spectrum can be targeted to distinguish the two substances,while other imaging methods have no such effect.The results showed that the different substances could be distinguished by the fusion technique.The results showed that pefloxacin and fluroxacin,the typical quinolone antibiotics,had obvious characteristic absorption peaks in terahertz band,and it was feasible to add types of antibiotics in fish meal feed and simultaneously detect the content of multiple antibiotics.At the same time,the terahertz fusion technique has great application potential in the visual characterization of the differences between the two substances.This study provides a theoretical and technical basis for the simultaneous qualitative and quantitative detection of multiple antibiotics by terahertz spectroscopy and the identification of antibiotics by terahertz imaging in animal husbandry.