色谱

色谱 ›› 2015, Vol. 33 ›› Issue (11): 1214-1218.DOI: 10.3724/SP.J.1123.2015.06022

• 技术与应用 • 上一篇    

酸水解-气相色谱法测定奶粉中的二十二碳六烯酸

邵仕萍, 相大鹏, 李双, 奚星林, 陈文锐   

  1. 广东出入境检验检疫局检验检疫技术中心, 广东 广州 510623
  • 收稿日期:2015-06-17 出版日期:2015-11-08 发布日期:2012-05-30
  • 通讯作者: 邵仕萍
  • 基金资助:

    广东省广州市科技计划项目(12S496140081).

Determination of docosahexaenoic acid in milk powder by gas chromatography using acid hydrolysis

SHAO Shiping, XIANG Dapeng, LI Shuang, XI Xinglin, CHEN Wenrui   

  1. Inspection and Quarantine Technology Centre, Guangdong Entry-Exit Inspection and Quarantine Bureau, Guangzhou 510623, China
  • Received:2015-06-17 Online:2015-11-08 Published:2012-05-30

PDF

130

被引次数

6

摘要：

建立了盐酸水解,索氏提取总脂肪酸,氢氧化钾甲醇溶液甲酯化,硫酸氢钠处理,气相色谱测定奶粉中二十二碳六烯酸(DHA)含量的方法。采用三因素三水平正交试验对氢氧化钾甲醇溶液甲酯化条件进行了优化,得到最优反应条件为:1 mol/L氢氧化钾在25 ℃反应5 min。甲酯化衍生液经硫酸氢钠处理,在SP-2560气相色谱柱(100 m×0.25 mm×0.20 μ m)上进行55 min程序升温测定DHA含量。DHA在5.0~300 mg/L范围内呈良好线性,相关系数为0.9999。DHA质量浓度为10、50、100 mg/L时目标峰峰面积的相对标准偏差(RSD)分别为3.4%、1.2%和1.1%。方法检出限为2 mg/kg,回收率为90.4%~93.5%。该法用于实际样品的检测,结果令人满意。

关键词: 二十二碳六烯酸, 奶粉, 气相色谱, 酸水解

Abstract:

A method to determine docosahexenoic acid (DHA) in milk powder by gas chromatography was established. The milk powder samples were hydrolyzed with hydrochloric acid, extracted to get total fatty acids by Soxhlet extractor, then esterified with potassium hydroxide methanol solution to form methyl esters, and treated with sodium hydrogen sulfate. The optimal experiment conditions were obtained from orthogonal experiment L9(33) which performed with three factors and three levels, and it requires the reaction performed with 1 mol/L potassium hydroxide solution at 25 ℃ for 5 min. The derivative treated with sodium hydrogen sulfate was separated on a column of SP-2560 (100 m×0.25mm×0.20 μ m), and determined in 55 min by temperature programming-gas chromatography. Good linearity was obtained in the range 5.0-300 mg/L with the correlation coefficient of 0.9999. The relative standard deviations (RSDs) were 3.4%, 1.2% and 1.1% for the seven repeated experiments of 10, 50 and 100 mg/L of DHA, respectively. The limit of detection was 2 mg/kg, and the recoveries of DHA were in the range of 90.4%-93.5%. The results are satisfactory through the tests of practical samples.

Key words: acid hydrolysis, docosahexenoic acid (DHA), gas chromatography (GC), milk powder

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