Rapid Determination Of Vitamins In Premixed Feed And Separation Of Eight Kinds Of Isomers In Natural Vitamin E

Vitamins generally can not be synthesized in animals and must be provided by diets.Livestock and poultry breeding process,in order to ensure that the animal needs for vitamins,tend to add vitamins in the diet in the form of implementation.Due to the low amount of vitamins in the feed end products,in order to ensure the uniformity of the added,generally in the feed production process to add premixed feed to achieve the purpose of adding vitamins.High performance liquid chromatography?HPLC?was used for the determination of vitamins in premix feed,and near infrared spectroscopy?NIRS?has been applied in recent years,but the applicability of this method is limited because of the complexity of premixed feed samples.In this study,the applicability of near infrared method was analyzed from the perspective of carrier diluent,and the change of near infrared model was analyzed due to the expansion of sample number.This study can provide a reference for establishing near infrared database.In addition,the simultaneous detection of 8 isomers of natural vitamin E in feed additive is very important for the rational use of natural vitamin E in feed.In this study,the fat soluble vitamins A and E were used as the research object,and the applicability of near infrared spectrum analysis method of vitamin A and E in different carrier premix feed was studied;Near infrared spectrum of different manufacturers of different varieties of premixed feed were collected by Fourier transform near infrared spectrometer,combined with partial least squares?PLS?method,spectral pretreatment method to establish quantitative analysis model of vitamin A and E of premixed feed,discusses the predictive ability of near infrared method of vitamin A and E content in premised feed;in addition,a new method for simultaneous determination of 8 isomers of natural vitamin E in premix feed was established.The major results and conclusions are summarized as follows:?1?The discriminate analysis of different scanning times and resolution on the quality of the near infrared spectroscopy were studied,and the peak values of vitamin A and E in different carrier diluent premixed feed and the quantitative accuracy of vitamin A and E models under different spectral pretreatment methods were compared and analyzed.The results showed the best spectral pretreatment is16 cm^-1 resolution and the 32 scans times.There were significant differences in the near infrared spectra and model of different carrier diluent premixed feed.The coefficient of determination?R_c²?for the NIRS calibration for the defatted rice bran as the carrier of the premix feed were 0.969,the coefficient of prediction?R_p²?were 0.935,the root mean square error of calibration?RMSEC?were 0.509,the root mean square error of prediction?RMSEP?were 0.772,while the ratio of prediction to deviation?RPD?were 9.07;the R_c² for the NIRS calibration for the powder as the carrier of the premix feed were 0.975,the R_p² were 0.975,the RMSEC were 0.460,the RMSEP were 0.451,while the RPD were 15.52;the R_c² for the NIRS calibration for the powder as the carrier of the premix feed were 0.975,the R_p² were 0.975,the RMSEC were 0.460,the RMSEP were 0.451,while the RPD were 15.52;the R_c² for the NIRS calibration for silica as carrier of the premix feed were 0.939,the R_p² were 0.926,the RMSEC were0.715,the RMSEP were 0.778,while the RPD were 8.99.From the angle of spectral characteristic peak extraction,silica had the greatest influence on the extraction of the characteristic peak of vitamin A,the second of defatted rice bran,the smallest of limestone powder.The R_c² for the NIRS calibration for the silica as carrier of the premix feed were 0.988,the R_p² were 0.989,the RMSEC were 7.64,the RMSEP were 8.86,while the RPD were 8.10;the R_c² for the NIRS calibration for the defatted rice bran as the carrier of the premix feed were 0.949,the R_p² were 0.980,the RMSEC were 14.66,the RMSEP were10.36,while the RPD were 6.90;the R_c² for the NIRS calibration for powder as carrier of the premix feed were 0.941,the R_p² were 0.921,the RMSEC were 16.16,the RMSEP were 23.37,while the RPD were3.07.From the angle of spectral characteristic peak extraction,powder had the greatest influence on the extraction of the characteristic peak of vitamin A,the second of defatted rice bran,the smallest of limestone silica.?2?A total of 49 samples of premixed feed were collected from Taigao Nutrition Technology?Beijing?imited company,an drandomly 49 samples diversity that calibration set: validation set is 40:9.The best pretreatment method of vitamin A is 1D+SNV and vitamin E is SNV.The near infrared analysis model of vitamin A and E had a higher predicted accuracy,the R_c² were 0.903 and 0.962,the R_p² were 0.894 and 0.953,the RMSEC were 5.02×10⁶ and 1.22×10⁴;the RMSEP were 5.61×10⁶ and1.81×10⁴;the RPD were 2.94 and 4.48.In order to increase the universality of the model,145 premixed feed samples randomly assigned to the calibration set: a validation set 109:36 was established for vitamin A near infrared model,the R_c² were 0.741,tne R_p² were 0.769,the RMSEC were 8.17×10⁶,the RMSEP were 1.88×10⁴;the RPD were 1.82;127 premixed feed samples randomly assigned to the calibration set: a validation set 106:21 was established for vitamin E near infrared model,the R_c² were0.868,the R_p² were 0.866,the RMSEC were 2.06×10⁶,the RMSEP were 2.28×10⁴;the RPD were2.70.The results showed that with the increase of the universality of the model,the prediction accuracy will decrease,and how to balance the range of the model and the accuracy of the model is one of the key factors in the application of near infrared technology.?3?Using high performance liquid chromatography?HPLC?method for simultaneous detection of8 kinds of isomers in natural vitamin E.The samples were dissolved with n-heptane and the optimal chromatographicconditions were as follows: the detection phase was 294 nm and the stationary phase was Kromasil 60-5 diol diol-based silica gel column.The mobile phase was n-heptane: tetrahydrofuran1000: 40.The flow rate was 1 m L/min and the column temperature was 30 °C.The standard solution of the eight isomers of vitamins was measured by gradient,and the standard curve was drawn and a good linearity was obtained.The detection limits and the limit of quantification were 0.1 mg/L and 0.2mg/L,respectively.The quantification limit of the method was 0.01%.The substrate was determined by matrix titer.The silica substrate was determined.The sample was centrifuged at room temperature for20 min and the volume was 10 m L.The membrane was pretreated as a sample by using 5%methanol/n-hexane as the extraction solvent.method.The recoveries of vitamin E isomers in different substrates were 80%¹15%,which was in accordance with the recovery range at a certain concentration level;accuracy?RSD%?? 10%.The natural vitamin E additive was tested under the optimizedoptimized HPLC conditions,and the more accurate results were obtained.