Predicition of Vitamin B₆ with Models Based on Near Infrared Spectrometry

The models for quantitative analysis of vitamin B₆ in compound vitamin B tablets for drug and vitamin B complex tablets for health products was established respectively by near infrared spectrometry combined with partial least square (PLS) method. 6-12 tablets of compound vitamin B tablets or vitamin B complex tablets were ground and oscillated at 4 000 r·min^-1 for 1 min, and the sample powder was respectively put into 3 sample cups. The near infrared spectra were collected by integrating sphere diffuse reflection analysis module. Each sample was collected 5 times, and 15 near infrared spectra were obtained. High performance liquid chromatography was used as the reference method, and different types of vitamin B tablets were used as modeling samples of the training set. In each sample, 12 spectra were used as the training set samples, and the remaining 3 spectra were used as the internal verification set samples. PLS method in TQ Analyst 9.0 was adopted, and the spectral data of the first derivative was used. 3 band ranges were selected for modeling (ranges of compound vitamin B tablets of 4 700.46-5 125.86 cm^-1, 5 444.60-5 708.26 cm^-1, 5 754.69-6 159.52 cm^-1; ranges of vitamin B complex tablets of 4 133.67-5 512.28 cm^-1, 5 944.17-6 495.08 cm^-1, 8 105.85-9 005.94 cm^-1). Norris derivative noise filter was used. The length of the segment was 5, and the interval between segments was 5 (compound vitamin B tablets) or 6 (vitamin B complex tablets). As shown by the results, quantitative analysis model of compound vitamin B tablets (model 2) of the corrected mean variance (RMSEC) was 0.003 0, with the corrected correlation coefficient (R_c) of 0.994 7, the predicted mean variance (RMSEP) of 0.002 9, the predicted correlation coefficient (R_p) of 0.995 4, the cross validation mean variance (RMSECV) of 0.005 2, the cross validation correlation coefficient (R_cv) of 0.994 1 and the performance index of 92.8. Quantitative analysis model of vitamin B complex tablets (model 3) of RMSEC was 0.031 4, with R_c of 0.998 7, RMSEP of 0.035 8, R_p of 0.998 7, RMSECV of 0.038 8, R_cv of 0.998 1, and the performance index of 93.5. Model 2 was used to predict the content of vitamin B₆ in compound vitamin B samples, and the absolute error and the relative error of prediction values were in the ranges of -0.004 4%-0.008 0% and -1.7%-3.3%, respectively. Model 3 was used to predict the content of vitamin B₆ in the vitamin B complex samples, and the absolute error and the relative error of prediction values were in the ranges of -0.007 1%-0.049 7% and -1.9%-5.0%, respectively.