机构地区: 教育部
出 处: 《分析试验室》 2005年第10期88-90,共3页
摘 要: 建立了非衍生毛细管气相色谱法直接测定紫苏子油中α-亚麻酸的方法.紫苏子油样品经0.5 mol/L的KOH-CH3OH溶液60 ℃皂化20 min、6 mol/L的HCl酸化后用无水乙醚萃取,氮气流吹干乙醚后用甲醇定容,然后直接进行气相色谱分析.结果表明,在0.991~89.1 ng的范围内,峰面积A与α-亚麻酸的质量m成线性关系,线性方程为:A=11253m+72.98,相关系数为0.9996(n=7).同一对照品溶液连续进样7次时,峰面积的相对标准偏差为0.76%.以S/N=3计算,方法的检出限为0.54 ng.被分析的紫苏子油中α-亚麻酸的质量分数为10.7%(RSD=1.24%,n=5),平均回收率为99.1%(RSD=3.7%,n=5). A method for the determination of α-linolenic acid in perillaseed oil was developed using the underivatized capillary gas chromatography (GC). The perillaseed oil was saponified by 0.5 mol/L KOH-CH3 OH solution for 20 min in 60℃ water bath, then acidified by 6 mol/L HC1 and finally, the dissociative fatty acids, including α-linolenic acid, was extracted by anhydrous ether. After the ether was blown out by nitrogen, the residuals were dissolved by 10 mL methanol. The calibration curve (A = 11253m + 72.98) was found to be linear over the range of 0.991 - 89.1 ng ( r = 0. 9996, n = 7) and the detection limit is 0.54 ng (S/N = 3). The average recovery is 99.1% and their relative standard derivation (RSD) is 3.7 % ( n = 5). When the same sample was analyzed for 7 times, the RSD of the area of the peak for α-linolenic acid is 0.76%. The percent content of a-linolenic acid in the determined perillaseed oil is 10.7 % ( RSD = 1.24 %, n = 5) and this is a little higher than the previous report.