Study On The Determination Of Nitrogen-containing Exogenous Pollutants In Milk By Infrared Spectroscopy

Objective:Near infrared spectroscopy(NIRS)technology was used for rapid identification of nitrogen adulterated substances in milk and calibration models were built which could analyze the adulteration milk..The samples were scanned with near-infrared spectrometer(NIRs)either directly by Fiber Optic Module or by Transmission Analyzer pretreated with trichloroacetic acid.Quantitative analysis models were built by TQ software and the two methods were compared.At the same time,to explore the feasibility of quantitative analysis of near infrared spectroscopy in peanut milk.Method:In order to analyze the content of nitrogen adulterated substances in milk quantitatively,samples were prepared with different gradients.The calibration models were built with infrared diffuse reflection spectrum and the near-infrared transmission spectrum of the samples with a pretreatment with trichloroacetic acid and then were validated.Optimize acquisition conditions and modeling conditions by TQ software.Prepare different contents of peanut milk,obtained by simulating the production process of peanut milk,and quantitative analysis model is established with NIRs.Result :The model of Ammonium chloride by Fiber Optic Module was established.The RMSEC,R,RMSEP was 0.0761,0.9914 and 0.5870,recovery was135.94 %.The model of Ammonium chloride by Transmission Analyzer was established.The RMSEC,R,RMSEP was 0.0324?0.9984 and 0.0498,recovery was 107.60 %.The model of melamine by Fiber Optic Module was established.The RMSEC,R,RMSEP was 0.0164,0.9835 and 0.0216,recovery was107.02 %.The model of melamine by Transmission Analyzer was established.The RMSEC,R,RMSEP was 0.00858,0.9955 and 0.0497,recovery was 105.03 %.The model of Hydrolyzed Vegetable Protein by Fiber Optic Module was established.The RMSEC,R,RMSEP was 0.224,0.214 and 0.9841,recovery was 93.24 %.The model of Hydrolyzed Vegetable Protein by Transmission Analyzer was established.The RMSEC,R,RMSEP was.0.175,0.138 and 0.9903 recovery was 98.73 %.2.The quantitative analysis model of milk powder was built,RMSEC,RMSEP,R was0.573,3.73 and 0.9997,recovery was 104.43 %.The quantitative analysis model of peanut was built,RMSEC,RMSEP,R was 0.066,0.183 and 0.9557,recovery was 103.99 %Conclusion:1.Both methods can be established the quantitative analysis model,thus could be used in rapid quantitative analysis of nitrogen adulterated substances in milk.The method has the advantages of small pollution,fast and efficient.2.The quantitative analysis model pretreated with tricholoroacetic acid could be more precise and stable,thus could be used in rapid quantitative analysis of nitrogen adulterated substances in milk.3.Near infrared spectroscopy could be used in the quantitative analysis of peanut milk and provided rapid detection for peanut milk.And the optimal model should be further studied.