大豆油中掺混地沟油的FTIR定量分析模型

Quantitative model for illegal cooking oil in soybean oil by FTIR

采用红外光谱(FTIR)和偏最小二乘(PLS)法,建立了地沟油掺混比例的衰减全反射(ATR)定量分析模型。分别采集大豆油、地沟油和二者不同掺混比例的红外光谱图,应用TQ化学计量学分析软件,对不同光谱的采集方式,不同化学计量学处理模式进行了比较,并对光谱区域,光谱的预处理方法,主成分因子数进行筛选。依据预测效果确定了最佳的预测模型,其相关系数为0.99,定标均方差(RMSEC)为4.31、预测均方差(RMSEP)为5.55。本法可用于地沟油鉴别的初期检测。

The quantification model of determining the content of illegal cooking oil in soybean oil was established by using reflectance Fourier transform infrared spectroscopy （FTIR） combined with a Partial Least Square （PLS）method. The samples of different content illegal cooking oil in soybean oil were made up. The influence of spectral collection, comparison of principle component regression （ PCA ） and PLS, selection of spectroscopic wavenumber region and principal component factor number were studied. The best model was selected according to the prediction effect. The correlation coefficients of prediction （ R^2 ）, the root mean square error of calibration （RMSEC） and the root-mean-square error of prediction （RMSEP） of the model were 0. 99, 4. 31 and 5.55, respectively. The proposed methods are simple, convenient, fast and non-destructive, and can be applied to the detection of illegal cooking oil.