Abstract: The separation of lactic acid from fermentation broth by using molecular distillation was studied. The experimental results showed that the product purity was 96% under the conditions：pH 2，vacuum 20～80 Pa，temperature 80 ℃. The lactic acid product was analyzed and the quality met the specifications of GB 2023—80，and the mass spectrum of was identical with standard lactic acid.

摘要： 以预处理后乳酸发酵液为对象，用分子蒸馏法来进行乳酸的分离提纯，在pH值为2、温度为80 ℃、进料速率为150～180 mL/h、真空度在20～80 Pa下得到了纯度为96%、耐热15 min的乳酸，同时分析了乳酸的其它几项指标并做了乳酸产品及标准品的质谱图对比。分析的指标中，完全达到GB 2023—80对乳酸的质量规定，并且乳酸产品与标准品的质谱图吻合很好。