利用乙腈作为内标气相色谱法快速测定发酵液中的乳酸

Determination of concentration of lactic acid in fermented broth by gas chromatography with acetonitrile as internal standard

建立了一种内标法准确、快速测定发酵液中乳酸含量的方法。色谱柱为2m×3mm(i.d.),内填GDX-103的不锈钢柱,FID检测器。内标为1.0%的乙腈溶液。实验结果表明,该方法的相对标准偏差小于1.0%(n=7),回收率在99%以上。方法具有前处理简单、干扰小、灵敏度高、分析速度快,线性测定范围宽等优点。

A gas chromatography （GC） method for the determination of lactic acid in fermentation broth was established. Acetonitrile solution with the concentration of 1.0 % was employed as the internal standard after extensive ,screening procedure. The chromatographic column selected was a stainless steel column with the dimension of 2m x 3mm （i. d. ）, and was filled with GDX-103. FID detector was used. This newly developed method was proved to be a rapid, simple and effective way to determinate the lactic acid content in the fermentation broth. The results would not be affected by other components in the broth. The relative standard deviation was less than 1.0% （n= 7） and the recovery was over 99%.