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 ana-lyzed by GC-MS. GC conditions were as follows:an HP-88 column(100 m×0. 25 mm×0. 2 μm) 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 auxil-iary( 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 reli-able and sensitive,and would be better if the background interference of fatty acids should be diminished by silver ion solid phase extraction.
参考文献
| [1] | Tyburczy, C.;Mossoba, M.M.;Rader, J.I..Determination of trans fat in edible oils: Current official methods and overview of recent developments Functional Foods and Dietary Supplements[J].Analytical and bioanalytical chemistry,201317(17):5759-5772. |
| [2] | Li J;Fan Y;Zhang Z;Yu H;An Y;Kramer JK;Deng Z.Evaluating the trans Fatty Acid, CLA, PUFA and Erucic Acid Diversity in Human Milk from Five Regions in China.[J].Lipids,20093(3):257-271. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%