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反相液相色谱法对米糠油中四种生育酚含量的测定

2018-07-18李晴周晓晴陈沙喻俊磊

湖北农业科学 2018年11期

李晴 周晓晴 陈沙 喻俊磊

摘要:建立了反相液相色谱法同时测定植物油中4种生育酚的方法。样品用甲醇超声提取,离心后取上清液氮吹至干,甲醇定容后过有机相滤膜,PEF柱(150 mm×3.0 mm,2.6 μm)分离,甲醇∶水(88∶12)作流动相等度洗脱,流速0.4 mL/min;柱温30 ℃;荧光检测(λex=294 nm,λem=328 nm)進样5 μL,外标法定量,在20 min内同时分离出α-、β-、γ-和δ- 4种生育酚异构体。4种生育酚的质量浓度在0.5~50.0 μg/mL与峰面积呈良好的线性关系,线性相关系数大于0.999。在3个添加水平下的平均加标回收率在84.47%~116.50%,相对标准偏差≤6.0%(n=6),α-生育酚、β-生育酚、γ-生育酚及δ-生育酚的方法检出限分别为0.10、0.05、0.05、0.04 mg/kg,表明该方法灵敏度高,回收率好,可应用于实际样品的分析。

关键词:反相高效液相色谱;荧光检测;生育酚;米糠油

中图分类号:O657.7+2 文献标识码:A 文章编号:0439-8114(2018)11-0087-04

DOI:10.14088/j.cnki.issn0439-8114.2018.11.021

Abstract: The method of simultaneous determination of 4 kinds of tocopherol in vegetable oil was established by reversed-phase liquid chromatography.After sample ultrasonic extraction with methanol,centrifugal supernatant liquid nitrogen blow to dry,the capacity after the methanol organic phase filter membrane,PEF column(150×3.0 mm,2.6microns) separation,methanol and water (88∶12) elution flow equal degree,velocity 0.4 mL/min;Column temperature 30 ℃;The fluorescence detection (a) of the sample volume was 5 μL,the external standard method was quantitatively determined,and the two types of paroxygenol isomers were isolated at the same time in 20 min. The mass concentration of 4 kinds of tocopherol was in a good linear relationship with the peak area within the range of 0.5~50.0 μg/mL,and the linear correlation coefficient was greater than 0.999. Adding in the three levels with respect to the average recovery was 84.47%~116.50%,relative standard deviation(RSD) for 6.0% or less(n=6),alpha tocopherol,beta tocopherol,gamma tocopherol and delta-tocopherol,method detection limit (LOD) were respectively 0.10,0.05,0.05,0.04 mg/kg. The method is accurate,sensitive and reliable,and can be applied to the analysis of actual samples.

Key words: inverse phase high performance liquid chromatography; fluorescence detection; tocopherol; rice bran oil

生育酚(Tocopherol)俗称维生素E,是人体代谢所必需的一种植物源性脂溶维生素,室温下为油状液体,橙黄或淡黄色,在热、酸等环境比较稳定,遇碱不稳定,易氧化。根据甲基的数目和位置的不同分为α-、β-、γ-和δ- 4种不同形式(结构式见图1)。4种生育酚的生物活性强度不同,如α-生育酚分布最广、生物活性最高,δ-生育酚抗氧化能力最强。生育酚对人体有重要的生理功能,具有抗氧化、抗衰老、抗不育、调节免疫力等作用,对生殖功能、细胞代谢均有影响[1],对一些临床疾病有积极的预防作用。植物油中含有丰富的生育酚[2-5],但不同植物油中生育酚的种类和含量有所不同。橄榄油、葵花子油、葡萄子油主要含有α-生育酚,核桃油、菜子油、亚麻子油、玉米油、大豆油中主要为γ-生育酚,另外大豆油中含有相对较高的δ-生育酚,米糠油含有最齐全的4种维生素E组分[6,7]。……

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