气相色谱-质谱联用法检测母乳脂肪中反式脂肪酸  

Determination of trans-fatty acid isomers in human milk fat by gas chromatography-mass spectrometry

作　　者：林麒[1] 李国波[2] 葛品[2] 许榕仙[3] 林国斌[1] 

机构地区：[1]福建省人兽共患病研究重点实验室(福建省疾病预防控制中心),福建福州350001 [2]福建省妇幼保健院(福建省妇儿医院),福建福州350001 [3]福建医科大学公共卫生学院,福建福州350108

出　　处：《色谱》2016年第5期520-527,共8页Chinese Journal of Chromatography

基　　金：福建省科技重大专项(2013YZ0002-1);福建省医药创新课题项目(2014-CXB-7)~~

摘　　要：建立了母乳中反式脂肪酸（TFAs）的气相色谱-质谱（GC-MS）检测方法,并应用于母乳脂肪中TFAs的检测。母乳用氨水水解,乙醚和石油醚提取脂肪,提取的脂肪加入C21∶0内标,用三氟化硼甲醇溶液在80℃水浴中冷凝回流15 min进行甲酯化,正己烷提取,上清液用GC-MS分析,内标法定量。在低、中、高加标水平上验证方法的准确度与精密度,结果显示该方法可用于母乳中18种TFAs及其同分异构体的检测,其中12种TFAs在母乳脂肪中的方法检出限为4.0-47.1 mg/kg,回收率为80%-113%,RSD为2.9%-14.5%（n=6）。TFAs在部分母乳脂样品中检出,含量为9.54-6.9 mg/kg。该方法定性、定量准确,可有效用于母乳中TFAs的检测,但仍存在脂肪酸本底干扰等问题,可结合银离子固相萃取柱预分离技术进一步完善。A method for the determination of trans-fatty acid isomers in human milk fat was developed by gas chromatography-mass spectrometry（GC-MS）,and applied to analyze TFAs in human milk fat. The fat was extracted with diethylether and petroleum ether after ammonia hydrolysis of human milk. C21 ∶0 internal standard and boron trifluoride methanol solution were added to the extract for fat esterification. The solution then was refluxed in 80 ℃ water bath for 15 min. Finally the trans-fatty acid methyl ester isomers were extracted with hexane,and analyzed by GC-MS. GC conditions were as follows：an HP-88 column（100 m ×0. 25 mm ×0. 2μm）with inlet temperature of 260 ℃,at a split ratio of 10 ∶1,and a He flow rate of 1 mL/min.The initial column temperature was 140 ℃（held for 5 min）,then raised up to 240 ℃ at a rate of 4 ℃/min（held for 15 min）. The electronic ionization（EI）source energy was 70 eV,with auxiliary（AUX）temperature of 280 ℃,ion source temperature of 230 ℃,quadrupole temperature of 150 ℃ in selected ion monitoring（SIM）mode. This method can analyze the 18 TFAs.The method detection limits（MDLs）of 12 TFAs were 4. 0-47. 1 mg/kg,and the average recoveries were 80%-113% with the relative standard deviation（RSD,n = 6）range of 2. 9%-14. 5%. TFAs were detected in some real samples and the contents were 9. 5-46. 9 mg/kg. The method is reliable and sensitive,and would be better if the background interference of fatty acids should be diminished by silver ion solid phase extraction.

关 键 词：气相色谱-质谱 反式脂肪酸 母乳 脂肪 

分 类 号：O658[理学—分析化学]