摘要
采用皂化气相色谱氢火焰离子检测器法测试了多个植物油样品,发现胆固醇峰被干扰比较严重,很难得出植物油与地沟油胆固醇含量的界定值。采用SPE进行样品前处理,对SPE处理条件进行优化,得出优化条件为称样量0.25 g,20 m L 0.6%乙醚-正己烷（V/V）作为淋洗液,20 m L 15%乙醚-正己烷（V/V）作为洗脱液。用SPE气相色谱氢火焰离子检测器法分析了84个植物油样品和13个地沟油样品中胆固醇含量,测定结果表明,植物油胆固醇含量与地沟油胆固醇含量有明显区别,所有植物油胆固醇含量都小于50μg/g,13个地沟油样中11个样胆固醇含量大于50μg/g。因此,采用上述植物油胆固醇测定方法,胆固醇含量超过50μg/g可判定为疑似地沟油,反之不成立。本方法在0-760 mg/L浓度范围内相关系数R2=0.9999,方法检出限为6.0μg/g,两个浓度水平（17.7和695 mg/L）的相对标准偏差分别为1.6%和1.5%,回收率为103%。
The contents of cholesterol in a number of vegetable oils were determined by saponification-gas chromatography（ FID）. There was quite a large possibility that cholesterol peak was seriously interfered by saponification-gas chromatography（ FID）,so it was difficult to set a cholesterol content value to differentiate vegetable oil from waste oil. Solid phase extraction（ SPE） sample pretreatment was chosen and the process conditions were optimized. The optimal conditions were as follows： 0. 25 g of oil samples,20 m L of 0. 6%ethyl ether-hexane（ V / V） as eluent（ get rid of fatty acid glycerides） and 20 m L of 15% ethyl ether-hexane（ V/V） as eluent（ obtain cholesterol）. An obvious cholesterol-content-difference between vegetable oils and waste oils was found by SPE-GC. The detected cholesterol contents in 84 vegetable oil samples were all less than 50 μg / g and the contents of 11 waste oil samples among the 13 waste oils were greater than 50 μg / g.Therefore,cholesterol content in vegetable oil of more than 50 μg / g could be determined as suspected waste oil,not vice versa by SPE-GC. The correlation coefficient R2 was 0. 9999 in 0- 760 mg / L concentration range,and the detection limit was 6. 0 μg / g. Relative standard deviations at two concentration levels of 17. 7and 695 mg / L were 1. 6% and 1. 5% respectively. The recovery was 103%.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2015年第3期394-398,共5页
Chinese Journal of Analytical Chemistry
基金
福建省科技厅(No.2012Y0053)
福州市科技局市科技局(No.2012-S-153)
福建省教育厅(No.JA12261)资助项目
关键词
地沟油
气相色谱
固相萃取
植物油
胆固醇
Waste oil
Gas chromatogray
Solid phase extraction
Vegetable oil
Cholesterol
