豆奶中苯甲酸、山梨酸的含量测定

Study on determination of benzoic acid and sorbic acid in soy milk

采用高效液相色谱法(HPLC)测定豆奶中的苯甲酸、山梨酸的含量。色谱条件为:流动相为甲醇与乙酸铵溶液(0.02 mol/L),体积比为5∶95,流速为1.0 mL/min,紫外检测波长为230 nm,进样体积为10μL。根据保留时间定性,采用外标法定量。结果表明,在0～200μg/mL范围内,回归方程相关系数大于0.99。苯甲酸和山梨酸的加标回收率分别在91.85%～95.72%,94.62%～102.4%。平行测定豆奶样品5次,相对标准偏差(RSD)分别为0.51%,0.96%,说明此方法分离速度快、准确度高、重现性良好。

The contents of benzoic acid,sorbic acid were tested in joy milk by using reversed-phase HPLC.An analytical method was set up to quickly determine benzoic acid and sorbic acid.Chromatographic conditions： methanol and 0.02 mol/L NH4Ac（5∶ 95） as the mobile phase,and flow rate is 1.0 mL/min,UV wave length of detection is 230 nm and injection volume is 10 μL.The qualitative analysis was determined by the retention time,the quantitative analysis was determined by the external standard method.The results showed that the good linear relationship was obtained in the range of 0~200 μg/mL,the correlation coefficient of regression equation of standard sample were more than 0.99.The recovery rate of benzoic acid and sorbic acid in joy milk were 91.85%~95.72%,94.62%~102.4%,respectively.When the sample in paralled determination for 5 times,the relative standard deviation of standard sample is 0.51% and 0.96%.It shows that this method has characteristics of quick separation,high accuracy and good reproducibility.