基于液相色谱-气相色谱联用测定巧克力中的饱和烃与芳香烃矿物油  

Determination of Mineral Oil Saturated Hydrocarbons and Aromatic Hydrocarbons in Chocolate by On-line Liquid Chromatography-Gas Chromatography

作　　者：谢尧卿 刘玲玲 李冰宁 欧阳杰[2] 武彦文 XIE Yaoqing;LIU Lingling;LI Bingning;OUYANG Jie;WU Yanwen(Beijing Center for Physical&Chemical Analysis,Beijing Food Safety Analysis and Testing Engineering Research Center,Beijing Academy of Science and Technology,Beijing 100094,China;College of Biological Sciences and Technology,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京市科学技术研究院北京市理化分析测试中心,北京市食品安全测试工程技术研究中心,北京100094 [2]北京林业大学生物科学与技术学院,北京100083

出　　处：《食品科学》2021年第12期288-294,共7页Food Science

基　　金：北京市自然科学基金项目(2182020);北京市科学技术研究院创新工程预研究项目(PXM2020_178305_000007)。

摘　　要：建立基于液相色谱-气相色谱(on-line liquid chromatography-gas chromatography,LC-GC)联用测定巧克力中饱和烃(mineral oil saturated hydrocarbons,MOSH)和芳香烃矿物油(mineral oil aromatic hydrocarbons,MOAH)的方法。该方法以正己烷于60℃超声提取20 min,取上清液以硅胶除去脂肪,以间氯过氧苯甲酸与烯烃进行环氧化反应,最后以LC-GC联用技术分离测定,其中LC用于保留油脂和烯烃环氧化物,同时分离得到MOSH和MOAH,通过由阀切换、保留间隙与溶剂排空阀组成的LC-GC接口分别将MOSH和MOAH导入2个平行的GC通道并以氢火焰离子化检测器测定。该方法的定量限为0.5 mg/kg,矿物油在0.5~85.5 mg/L内线性关系良好(R2=0.998),加标回收率为80.3%~93.8%,相对标准偏差为1.58%~8.22%。测定了28个巧克力产品中的矿物油含量,其中有20个产品检出MOSH,含量为1.83~22.23 mg/kg,1个检出1.57 mg/kg MOAH。谱图分析表明,一些产品中含有塑料迁移出的聚烯烃低聚饱和烃(polyolefin oligomeric saturated hydrocarbons,POSH),LC-GC无法分离POSH与MOSH,因此测得结果实际上是MOSH和POSH的总量。A method for the determination of mineral oil saturated hydrocarbons(MOSH)and mineral oil aromatic hydrocarbons(MOAH)in chocolate was established using on-line liquid chromatography-gas chromatography(LC-GC).Samples were extracted with n-hexane while sonicating at 60℃for 20 min,and the collected supernatant was treated with silica gel for lipid removal.Then epoxidation was employed with m-chloroperoxybenzoic acid in order to oxidize the endogenic olefins in samples.Finally,the separation and determination were conducted by LC-GC,in which LC was used to retain both oil and olefin epoxide,and the isolated MOSH and MOAH were separately introduced into the two parallel GC channels through the LC-GC interface consisting of transferring valves,retention gaps and solvent release valves and detected with a flame ionization detector.The calibration curves for MOSH and MOAH were linear in the range of 0.5–85.5 mg/L(R2=0.998),and the limit of quantification(LOQ)of the method was 0.5 mg/kg.The spiked recoveries were in the range of 80.3%–93.8%with relative standard deviation(RSD)of 1.58%–8.22%.This method was used to determine the mineral oil in 28 commercial chocolate products,of which 20 samples were found to contain MOSH in the range of 1.83–22.23 mg/kg and 1 sample was found to contain MOAH at 1.57 mg/kg.The analysis of on-line LC-GC chromatograms demonstrated that some chocolate products contained polyolefin oligomeric saturated hydrocarbons(POSH)migrating out from plastic packages.POSH and MOSH could not be separated from each other by on-line LC-GC,so the measured results were actually the total amount of MOSH and POSH.

关 键 词：巧克力 饱和烃矿物油 芳香烃矿物油 液相色谱-气相色谱 环氧化反应 

分 类 号：TS207.3[轻工技术与工程—食品科学]