食品科学 ›› 2008, Vol. 29 ›› Issue (6): 357-360.

• 分析检测 • 上一篇    下一篇

对羟基联苯法定量测定发酵液中的乳酸

 梁琼, 鲁明波, 卢正东, 何锋, 余龙江   

  1. 华中科技大学生命科学与技术学院 资源生物学与生物技术研究所; 华中科技大学生命科学与技术学院; 资源生物学与生物技术研究所; 湖北武汉430074;
  • 出版日期:2008-06-15 发布日期:2011-08-26

Determination of Lactic Acid in Fermentation Broth by p-Hydroxybiphenol Colorimetry

 LIANG  Qiong, LU  Ming-Bo, LU  Zheng-Dong, HE  Feng, YU  Long-Jiang   

  1. Institute of Resource Biology and Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
  • Online:2008-06-15 Published:2011-08-26

摘要: 对传统的对羟基联苯法进行了优化,应用于定量测定发酵液中的乳酸。首先对发酵液进行适当预处理,去掉蛋白质和葡萄糖,再利用正交设计对影响显色的几个重要因素进行了优化,结果表明,最佳测定波长为565nm;最佳显色条件为氢氧化钙0.05g,20%硫酸铜0.8ml,浓硫酸6ml,0.5%对羟基联苯0.125ml,静置时间15min,加热显色时间5min。标准曲线回归方程为A=0.0189C-0.0808(n=8),r=0.9989。在15~50μg/ml范围内呈良好线性关系。平均回收率为102.4%。显色稳定保持2h以上,RSD为2.6%(n=12)。该方法解决了传统对羟基联苯法显色时间长、准确度不高等问题,适合于发酵液中乳酸含量的测定。

关键词: 乳酸, 定量测定, 对羟基联苯法, 正交设计

Abstract: An improved colorimetric method was developed for the determination of lactic acid in fermentation broth. Firstly, the fermentation broth was given a suitable treatment that the protein and glucose were removed, and then the traditional colorimetry method applied for the determination of lactic acid was optimized by orthogonal test. The results showed that the optimum absorbance wavelength is 565 nm. The optimal colorimetric conditions are: 0.05 g Ca(OH) 2, 0.8 ml 20% CuSO4, 6 ml concentrated H2SO4, 0.125 ml 0.5% p-hydroxydiphenyl,reaction time 15 minutes and heating time 5 minutes. Linear range is 15~50μg/ml (A=0.0189C-0.0808, r=0.9989). The average recovery is 102.4%. The color development for determination of lactic acid by colorimetric method is stable within more than two hours, and the RSD is 2.6% (n=12). The method established in this study is quick, accurate and stable.

Key words: lactic acid, determination, p-hydroxybiphenol colorimetry, orthogonal test