紫外双波长-pH转换法同时测定混合物中的丙酮酸和乳酸

建立了一种同时测试混合物中乳酸与丙酮酸含量的紫外分光光度方法。在碱性环境下,利用双波长法,测定混合物中的丙酮酸,线性回归方程C=6.75×10-3+0.626A,线性范围为0.0505⁰.505μg/mL;在酸性条件下,利用直接分光光度法,测定混合物中的乳酸,线性回归方程C=1.547+51.76A,线性范围为1.22²44μg/mL。采用本法测量工业样品,其结果与液相色谱法得到的数据基本吻合,但本法实验步骤更加简单、操作更加方便,且容易实现工艺过程的在线检测。 

Simultaneously determination of pyruvic acid and lactic acid by using dual-wavelength spectrophotometry and changing the pH of the system

A simple and rapid UV spectrophotometric method for simultaneous determination of pyruvic acid and lactic acid in their mixture was proposed. Pyruvic acid was determined in strong alkaline medium by using dual-wavelength spectrophotometry and Linear equation (C=6.75×10-3+0.626A) was obtained. Beer's law was obeyed in the range from 0.0505 to 0.5050μg/mL, the determination of lactic acid could be carried out directly in acid medium with good accuracy, a linear relation (C=1.547+51.76A) in the range from 1.22 to 244μg/mL. The method had been applied to evaluate catalytic oxidation reaction in the synthesis of lactic acid and the result attained was identical to one by mean of HPLC, however, this method was more convenient, easier and suitable for online analysis of the industrial products.