柱前衍生-气相色谱法测定血浆中十五烷酸的含量

DETERMINATION OF PENTADECANOIC ACID IN PLASMA BY PRE-COLUMN DERIVATIZATION GAS CHROMATOGRAPHY

目的建立一种简便易行的气相色谱法(GC)检测血浆中十五烷酸的含量。方法以正十七碳饱和脂肪酸(C17:0)为内标,对硫酸/甲醇法甲酯化脂肪酸的条件进行简单对比试验及正交试验,考察了硫酸/甲醇浓度、水浴温度和水浴时间;选取最佳的脂肪酸甲酯化条件对样品中的正十五烷酸(C15:0)进行甲酯化,再抽提脂肪酸甲酯,采用配有氢火焰离子化检测器(FID)的气相色谱仪定量分析。结果硫酸/甲醇甲酯化法选用的硫酸/甲醇浓度10%,水浴温度70℃,水浴时间45 min时,甲酯化效率最高。本法的测定范围为0.5~100μg/ml,相关系数r=0.9956,方法检出限为0.15μg/ml。样品加标回收率为95.1%~104.5%;批内精密度为0.16%~2.20%,稳定性为1.06%~5.37%。结论柱前衍生-气相色谱法可以简便快速测定血浆中C15:0的含量,具有较高的准确度和重复性。[营养学报,2020,42(5):505-508,513]

Objective To establish a simple method for determination of the content of pentadecanoic acid in plasma by gas chromatography(GC).Methods The concentration of sulfuric acid/methanol solution,water bath temperature and water bath time were investigated by simple comparison method with heptadecanoic(C17:0) as the internal standard to determine the most suitable condition for fatty acid methyl esterification.Methyl esterification of pentadecanoic(C15:0) in the sample was conducted by the best condition,followed by pre-column derivatization.Qualitative and quantitative analysis was conducted by gas chromatography equipped with hydrogen flame ionization detector(FID).Results When the concentration of sulfuric acid/methanol was 10%,the temperature of the water bath was 70℃,and the time of the water bath was 45 minutes,the methylation efficiency was the highest.The detection range of this method is 0.5-100 μg/ml(r=0.9956),the detection limit of this method is 0.15 μg/ml,and the recovery rates were 95.1%-104.5%.The intra batch precision was0.16%-2.20%(n=5),and the stability was 1.06%-5.37%(n=4).Conclusion Pre-column derivatization gas chromatography can easily and quickly determine the C15:0 in plasma,with high recovery rate and accuracy.[ACTA NUTRIMENTA SINICA,2020,42(5):505-508,513]