HPLC法测定苹果酒中苹果酸及乳酸含量

Content determination of malic acid and lactic acid in cider by HPLC

建立了HPLC测定苹果酒中苹果酸及乳酸含量的方法,即采用配紫外检测器及Symmetry C18(3.5μm×4.6mm×75mm)色谱柱的液相色谱仪,柱温25℃,流动相为含0.1%甲酸的甲醇水溶液,流速0.5mL/min,检测波长210nm,进样量20μL,通过外标法定量研究苹果酒中苹果酸及乳酸的含量。研究结果表明:该法定量线性关系良好(苹果酸标准曲线的线性相关系数R^2为0.9969,乳酸的R^2为0.9999);日内进样保留时间相对标准偏差(RSD)在0.12%以内,峰面积RSD在2%以内,日间进样保留时间的RSD在0.12%以内,峰面积的RSD在1.82%以内;苹果酸的最低检出限(LOD)(S/N≥3)可达0.43mg/L,最小检测量(LOQ)(S/N≥10)可达1.30mg/L,乳酸的LOD可达1.12mg/L,LOQ为3.36mg/L。上述方法对于测定苹果酒中苹果酸及乳酸含量线性关系良好、重现性好、灵敏度高。

A method to detect malic acid and lactic acid contents of cider by HPLC that containing UV detector and Symmetry C18（3.5μm×4.6mm×75mm） column was established.The column temperature was 25℃, mobile phase consisted of methanol containing 0.1%formic acid,the rate of flowing was 0.5mL/min,detection wavelength was 210nm,the injection volume was 20μL.Malic acid and lactic acid contents were detected by external standard method.The analysis results showed that correlation coefficient of the linear equation was high（it was R^2=0.9969 for malic acid and R^2=0.9999 for lactic acid）.The relative standard deviation（RSD） of retention time within one day was less than 0.12%and the RSD of the peak area within one day was less than 2%, RSD of retention time in different days was below 0.12%and the RSD of the peak area in different days was below 1.82%.For malic acid,the limit of detection（LOD） was 0.43mg/L（S/N≥3）,the limit of quantity（LOQ） was 1.30mg/L（S/N≥10）.For lactic acid,the LOD was 1.12mg/L and the LOQ was 3.36mg/L.It was a suitable way to determine malic acid and lactic acid contents of cider with great linear relationship,favorable reproducibility and high sensitivity.