衰减全反射傅里叶变换红外光谱测定米粉中硒代甲硫氨酸的含量

利用衰减全反射傅里叶变换红外光谱法测定米粉中硒代甲硫氨酸含量，以期探寻一种快捷、绿色环保的食品中硒含量的测定方法。通过采用添加硒代甲硫氨酸制备样品，衰减全反射中红外光谱仪采集红外光谱，TQ Analyst分析软件进行偏最小二乘法建模并验证，结果表明，选择1 600～650 cm－1作为样品的红外光谱分析波段，用导数对原始红外光谱处理后，采用留一和留多两种方法均获得良好的预测效果。比较而言，一阶导数处理后的留一模型，计算简单且预测效果更好。留一模型的决定系数RC 2 均大于0.997，因子数均为6，校正均方差为1.76～1.9，留一验证预测决定系数RP2为0.986 8，预测均方差为3.27，相对分析误差为8.612 9，预测值相对偏差在20%以内的占92.91%，10%以内占82.27%。

Determination of Selenium Methionine in Rice Flour by Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

Attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to determine the selenium methionine content in rice flour in order to develop a fast and environmentally friendly method for the determination of selenium in food. IR spectra of samples with added selenomethionine were collected by an attenuated total reflection mid-infrared spectrometer. The partial least square method was used to develop a mathematical model and the model was validated by TQ Analyst software. The results showed that the infrared spectra in the range of 1 600–650 cm-1 were selected for analysis. After derivative preprocessing of the original infrared spectra, good prediction results were obtained by using either the leave-one-out method or the leave-more-out method. Comparatively, the leaveone- out model with first derivative pretreatment was simpler in calculation and gave more accurate prediction. The coefficient of determination for calibration (RC 2 ) of the left-one-out model was greater than 0.997, the number of factors was 6, the root mean square error of calibration (RMSEC) was 1.76–1.9, the coefficient of determination for prediction (RP 2) was 0.986 8, the root mean square error of prediction (RMSEP) was 3.27, and the relative prediction deviation (RPD) was 8.612 9. The predicted values with a relative deviation of less than 20% and 10% accounted for 92.91% and 82.27% of the total, respectively.