Study On The Elisa Determination Method Of Aflatoxins In Corn

Aflatoxin is mainly composed of Aspergillus flavus and parasitic Aspergillus and other fungi produce toxic metabolic products, widely exists in grain cereals and processed foods, in numerous mould toxin, aflatoxin B1 toxic, carcinogenic and strong, stable in physical and chemical properties,can be transferred between organisms in the food chain, hazards to human health greatly. Aflatoxin B1 is food health indicators will be seized items.Detection mechanism commonly used in conventional thin-layer chromatography (TLC) national standard method to detect aflatoxin B1 (AFB1), aand liquid phase color spectrum (HPLC) law compared to, the TLC method is simple, economical, but the fluorescence intensity of the estimation accuracy is poor, HPLC method has high cost, long time, detection accuracy high characteristic, both of which are not suitable for large quantities of samples, rapid detection.Harvesting grain and stock food detection of mycotoxins, often in large quantities, time is close, the common laboratory using enzyme immunoassay (ELISA) kit for screening, because the city for ELISA kit brand more, technical grade, pretreatment method and operation method are not the same, different kit has the determination results the deviation.In this paper, sale of mycotoxins ELISA kit for testing, research and analysis kit the stability of test results, the precision and accuracy, to select the application kit.Research has established a new ELISA detection method for sample pretreatment in the optimal value, ELISA method is proved feasibility for grain in AFB1 analysis, and by high performance liquid chromatography key validation the test sensitivity, linearity, detection of repetitive, recovery rate, stability index.The optimization of the experimental conditions, new production for 2011 events in Nantong, Jiangsu Province, AFB1 in corn-producing pollution were investigated, research findings are as follows:1,Choosing the domestic market of three mycotoxins ELISA kit for testing, research and analysis of three kit test results of stability, precision and accuracy, the results show that, C manufacturers of kit in the stability, precision and accuracy on the effect best, so the study of selection of C factory kit for application.2, Taking corn as experimental material, system research of different extraction solution concentration, extraction time, extraction solution volume, extraction temperature on ELISA detection results, exploring the effects of different factors on the determination of the result size.Results show that the sample preparation in the volume of methanol solution concentration, extract, extraction and extraction temperature on the ELISA test results have a significant effect; orthogonal test analysis results show that the ELISA test results influence most notably methanol concentration, followed by the volume of extraction solution extraction, extraction time, and temperature. The paper establishes a new ELISA method for the determination of maize AFB1 pretreatment parameters:60 mesh fineness,7 times the 75% methanol solution and heating to 30℃, the oscillation of 45min extraction.By high performance liquid chromatography ELISA test kit key validation, HPLC method for the determination of AFB1 standard curves in 200μg/mL to 0.2μg/mL concentration dilution process does not produce deviation, the linear correlation coefficient of 1.In addition at the concentration of 0.1-20ug/kg, HPLC and recovery rate of 68%-88%, ELISA method of recovery is in the range of 60%-108%, data display, the ELISA method for the determination of linear coefficient is 0.9978, the sensitivity was 0.0497 ug/L, ELISA method for the determination of maize AFB1 and HPLC method for the determination of the recovery rate when quite.3,A new investigation of AFB1 in corn-producing pollution in Nantong, Jiangsu Province (six counties)in 2011 produced that, among 189 samples,11 samples were detected in AFB1,6 of which content exceeds national standards for 20μg/kg, the maximum value is 57μg/kg, the positive rate of only 5.82%, not the qualified rate is 3.17%.