吸收光谱法同时检测食品中的苯甲酸钠与山梨酸钾

利用苯甲酸钠和山梨酸钾的紫外吸收光谱特性,设计了正交试验,结合偏最小二乘变量筛选法,获得变量数少、相关系数高、预报准确性好、能同时对苯甲酸钠和山梨酸钾进行浓度预报的模型,并应用于饮料、蜜饯、糕点和调色酒样品中苯甲酸钠和山梨酸钾的检测。样品平行测定结果的相对标准偏差均小于10%,方法的加标回收率为82%～107%,苯甲酸钠和山梨酸钾的检测范围分别为0.1～16.0 mg.L-1和0.1～6.0 mg.L-1,检出限分别为0.05 mg.L-1和0.01 mg.L-1。样品的检测结果与国标法的检测结果相吻合。

Simultaneous Determination of Sodium Benzoate and Potassium Sorbate in Food by Absorption Spectrometry

Based on the UV-Vis absorption characteristics of preservatives and partial least squares variable selection method,the concentration forecasting model of benzoic sodium and sorbic potassium mixture solution was studied.The ultraviolet absorbance spectra of these complexes were examined,and the results indicated that the response signals and concentrations presented good linearities in the ranges of 0.1-16.0 mg/L for benzoic sodium and 0.1-6.0 mg/L for sorbic potassium.The detection limits were 0.05 mg/L for benzoic sodium and 0.01 mg/L for sorbic potassium.The reported model was applied in the simultaneous determination in food samples such as drinks,wine,cake and preserves without any preliminary chemical separation.The relative standard deviations were less than 10% and the recoveries were in the range of 82%-107%.The detection data are consistent with those of the national standard method.