气相色谱法测定婴幼儿配方乳粉中二十二碳六烯酸前处理方法的改进  

Improvement of pretreatment method for determination of docosahexaenoic acid in infant formula milk powder by gas chromatography

作　　者：党亚敏[1] 李建平[1] DANG Ya-min;LI Jian-ping(Department of Physics and Chemistry,Tianjin Center for Disease Control and Prevention,Tianjin,300011,China)

机构地区：[1]天津市疾病预防控制中心理化科,天津300011

出　　处：《职业与健康》2023年第2期175-178,共4页Occupation and Health

摘　　要：目的 对气相色谱法测定婴幼儿配方乳粉中二十二碳六烯酸(docosahexaenoic acid,DHA)前处理方法进行改进。方法 改进的方法采用在50 mL聚丙烯离心管中进行脂肪的水解、提取、皂化和甲酯化,避免了传统加热回流装置以及液液萃取分液漏斗的使用。结果 DHA标准溶液在9.54~191.00μg/mL浓度内呈良好的线性关系,相关系数r为0.999 8;方法的检出限为0.001 g/100 g,定量限为0.003 g/100 g;样品分别加入低、中、高3个浓度水平的DHA标准,加标回收率为84.3%~108.0%,6次重复测定相对标准偏差(RSD)均<10%。对婴幼儿配方乳粉质控样和考核样中的DHA进行测定,测定结果均在其标识值范围内。结论 改进后的前处理方法简便、快速,适合婴幼儿配方乳粉中DHA的大批量检测。Objective To improve the pretreatment method for determination of docosahexaenoic acid(DHA) in infant formula milk powder by gas chromatography.Methods The improved method adopts hydrolysis,extraction,saponification and methyl esterification of fats in 50 mL polypropylene centrifuge tubes,which avoids the use of traditional heating reflux devices and liquidliquid extraction and separation funnels.Results The DHA standard solution showed a good linear relationship between 9.54 and191 μg/mL concentration,and the correlation coefficient r was 0.999 8.The detection limit of the method was 0.001 g/100 g and the quantitative limit was 0.003 g/100 g.The samples were added to the DHA standards of low,medium and high concentration levels,and the recovery rate of the standard was 84.3%-108.0%,and the relative standard deviation(RSD) was <10% for six repeated measurements.The DHA in the quality control sample and examination sample of infant formula milk powder was determined,and the measurement results were within the range of their identified values.Conclusion The improved pretreatment method is simple and fast,and is suitable for the large-scale detection of DHA in infant formula milk powder.

关 键 词：脂肪酸 甲酯化 二十二碳六烯酸 乳粉 

分 类 号：R115[医药卫生—公共卫生与预防医学]