乳粉中1-油酸-2-棕榈酸-3-亚油酸甘油三酯的测定

Determination of 1-Oleic-2-Palmitic-3-Linoleic Acid Triglyceride in Infant Formula

建立乳粉中1-油酸-2-棕榈酸-3-亚油酸甘油三酯(1-oleic-2-palmitic-3-linoleic acid triglyceride,OPL)的气相色谱检测方法。样品经乙醚和石油醚提取,提取液浓缩近干,正庚烷定容,通过CP-TAP CB弹性石英毛细管柱分离,以氢火焰离子化检测器检测,外标法定量。结果表明:通过CP-TAP CB弹性石英毛细管柱程序升温分离,进样口温度330℃,分流进样,分流比1∶10,进样体积1.0μL;氢火焰离子化检测器温度360℃,载气:氮气,尾吹流量(氮气)25 mL/min;乳粉中OPL的添加量为1~6 g/100 g时,加标回收率为95.2%~101.9%,相对标准偏差为1.289%~1.998%;方法的检出限为0.2 g/100 g,定量限为1.0 g/100 g。该方法操作简单、结果准确、重复性好,适用于乳粉中OPL的测定。

A gas chromatographic(GC)method for the determination of 1-oleic-2-palmitic-3-linoleic-triglyceride(OPL)in milk powder was established.The samples were extracted with ether and petroleum ether,and the extract was concentrated to near dryness,re-dissolved in n-heptane,separated on a CP-TAP CB elastic quartz capillary column,detected by a hydrogen flame ionization detector,and quantified by an external standard method.The column temperature was programmed to rise.The inlet temperature was set at 330℃.The samples(1.0μL)were injected using the split mode(1:10).The detector temperature was set at 360℃.Nitrogen was used as the carrier gas.The makeup flow rate(nitrogen)was 25 mL/min.The recovery of OPL from spiked milk powder at 1–6 g/100 g ranged from 95.2%to 101.9%,and the relative standard deviations(RSDs)for precision ranged from 1.289%to 1.998%.The limit of detection(LOD)and limit of quantitation(LOQ)of the proposed method were 0.2 and 1.0 g/100 g,respectively.This method,therefore,is simple,accurate,repeatable,and suitable for the determination of OPL in milk powder.