Research On Sensitive And Rapid Detection Technology For Melamine And Aflatoxin M₁ In Dairy Products

With the improvement of our country’s living standards,dairy products with enrich nutrition play an important role in people’s lives.However,there are many incidents of quality and safety in dairy products in recent years,such as illegal addition,Mycotoxins,which have caused serious health and economic losses to consumers.Rapid on-site detection technology is the core method to ensure the quality and safety of dairy products.Because of the complex operation,expensive instruments and professional technicians,the existing detection technology of large scale is difficult to satisfy the requirements of rapid on-site detection.Therefore,established a highly sensitive and rapid detection technology for chemical contaminants in dairy products,it is great significance to ensure the quality and safety of dairy products and the health of consumers.Based on the immunoassay principle,this study used time-resolved fluorescence immunochromatography technology to establish a highly sensitive and rapid detection technique for melamine and aflatoxin M₁ in dairy products.It provided technical support for the detection of chemical contaminants in dairy products.The main research contents and innovations of this study are as follows:1.In this work,the Eu@polystyrene microspheres was the mark material and melamine was the analytes.Coupled the Eu@polystyrene microspheres with high specific anti-melamine mAb,by optimizing anti-melamine mAb amounts and relevant parameters to immunochromatography,time-resolved fluorescence detecting strips based first antibody for melamine analysis were fabricated.The method was applied for melamine detection in peanut,walnut,and coconut beverages.The lower limit of detection（LOD）was 0.89,0.94,and 1.05 ng/mL and the linear range was 2.67–150,2.82–150,and3.15–150 ng/mL（R²>0.982）for peanut,walnut,and coconut beverages,respectively.The recovery rates were 85.86¹10.60%with a coefficient of variation（CV）<7.80%using the spiking experiment.The high specificity was observed according to the interferential experiment.These results demonstrated that method had acceptable repeatability and reproducibility.When detecting the real protein beverage samples,the results from this method and ultra-performance liquid chromatography-tandem mass spectrometer（UPLC-MS/MS）were consistent,the recoveries rates were 82.21%¹10.80%.2.The Eu@polystyrene microspheres was used mark material and melamine was the analytes.Coupled the Eu@polystyrene microspheres with goat anti-mouse IgG,by optimizing relevant parameters to immunochromatography,time-resolved fluorescence detecting strips based bi-antibody for melamine analysis were fabricated.The method was applied for melamine detection in milk.The lower limit of detection（LOD）was 0.024ng/mL and the linear range was 0.072–150 ng/mL（R²=0.985）for milk.The recovery rates were 90.00%¹13.20%with a coefficient of variation（CV）<7.75%using the spiking experiment.These results demonstrated that method had acceptable repeatability and reproducibility.The high specificity was observed according to the interferential experiment.Compared the method with ultra-high performance liquid chromatography tandem mass spectrometry,the recoveries rates were 84.46%¹04.26%.3.The Eu@polystyrene microspheres was used mark material and aflatoxin M₁ was the analytes.Coupled the Eu@polystyrene microspheres with goat anti-mouse IgG,by optimizing relevant parameters to immunochromatography,time-resolved fluorescence detecting strips based bi-antibody for aflatoxin M₁ analysis were fabricated.The method was applied for aflatoxin M₁ detection in milk.The lower limit of detection（LOD）was0.009 ng/mL and the linear range was 0.027–0.4 ng/mL（R²=0.995）for milk.The recovery rates were 96.00%¹04.75%with a coefficient of variation（CV）<8.13%using the spiking experiment.These results demonstrated that method had acceptable repeatability and reproducibility.When detecting the real protein beverage samples,the results from this method and high performance liquid chromatography（HLPC）were consistent,the recoveries rates were 79.17%¹09.38%.