School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200241, China.
Chonqing Institute of Forensic Sciences, Chongqing 400021, China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2020 Nov 20;1158:122344. doi: 10.1016/j.jchromb.2020.122344. Epub 2020 Aug 29.
Capsaicinoids, including capsaicin, dihydrocapsaicin and N-vanillylnonanamide have been identified as characteristic markers for gutter oil. In this study, the nanocomposite of graphene oxide-FeO (GO-FeO) was synthesized by a co-precipitation method, and applied to magnetic solid phase extraction (MSPE) process. The capsaicin, dihydrocapsaicin and N-vanillylnonanamide extracted in gutter oil were analyzed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Under the optimized pretreatment conditions, the limit of detection (LOD) and limit of quantification (LOQ) are 0.15 and 0.4 µg L, respectively. The linear range is 0.4-200 µg L, and the correlation coefficients (R) are over 0.996 for all three compounds. The recoveries range from 81.2% to 103.3% for soybean oil and 71.2% to 84.3% for rapeseed oil. The values of matrix effect range in 87.6%-105.5% and 83.4%-110.6% and the intra-day RSDs range from 2.8%-4.6% to 4.8%-6.1% for soybean oil and rapeseed oil, respectively. The adsorbent can be reused for multiple times with no appreciable loss of adsorption capability. The present methodology has high potential for screening of gutter oil in food samples, thus having importance for food safety monitoring.
辣椒素类物质，包括辣椒素、二氢辣椒素和 N-香草基壬酰胺，已被确定为地沟油的特征标志物。本研究采用共沉淀法合成了氧化石墨烯- FeO（GO-FeO）纳米复合材料，并将其应用于磁性固相萃取（MSPE）过程。用超高效液相色谱-串联质谱法（UHPLC-MS/MS）分析地沟油中提取的辣椒素、二氢辣椒素和 N-香草基壬酰胺。在优化的预处理条件下，检测限（LOD）和定量限（LOQ）分别为 0.15 和 0.4μg/L。线性范围为 0.4-200μg/L，所有三种化合物的相关系数（R）均大于 0.996。在大豆油中的回收率范围为 81.2%-103.3%，在菜籽油中的回收率范围为 71.2%-84.3%。基质效应值在 87.6%-105.5%和 83.4%-110.6%之间，日内 RSD 分别在 2.8%-4.6%至 4.8%-6.1%之间，适用于大豆油和菜籽油。该吸附剂可重复使用多次，且吸附性能无明显损失。本方法具有在食品样品中筛查地沟油的潜力，因此对食品安全监测具有重要意义。
