Yang Guangxin, Tang Yunyu, Liu Xiaoxia, Wang Longlong, Qin Lixia, Li Dan, Shen Xiaosheng, Kong Cong, Zhai Wenlei, Fodjo Essy Kouadio, Fan Chengqi
Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural Affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China.
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, 100 Haiquan Road, Shanghai 201418, China.
Foods. 2024 Jul 25;13(15):2340. doi: 10.3390/foods13152340.
This study introduces a novel method for detecting free glycidol and total free monochloropropanediol (MCPD) in fish and krill oil. Before analysis on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS), -(dimethylamino)phenol was used for derivatization of these compounds, enabling the sensitive determination of these contaminants. The sample preparation procedure includes a simple, efficient pretreatment using NaCl aqueous solution extraction and C18 sorbent cleanup (for demulsification), distinguishing glycidol from MCPD under varied reaction conditions for derivatization (weak acidic and strong alkaline aqueous environments). This approach shows broad linearity from 1 to at least 256 ng·mL, improved sensitivity compared to standard GC-MS methods, with the limit of detection (LOD) and limit of quantification (LOQ) for MCPD and glycidol in both oil samples verified at 0.5 ng·mL and 1 ng·mL, respectively. Different from previous HPLC-MS methods for direct detection of glycidol esters or MCPD esters, this is the first HPLC-MS method used for the detection of free glycidol and total free MCPD in edible oil. Furthermore, this method can be potentially developed for glycidol or monochloropropane diol esters, which is similar to the current official methods adopted for indirect detection of these contaminants in different food matrices. Application of this detection method to real dietary supplements (fish oil and krill oil) revealed MCPD residues in fish oil (maximum detected: 32.78 ng·mL) and both MCPD (maximum detected: 2767.3 ng·mL) and glycidol (maximum detected: 22.2 ng·mL) in krill oil, emphasizing its effectiveness and accuracy for assessing contamination in these supplements.
本研究介绍了一种检测鱼油和磷虾油中游离缩水甘油和总游离单氯丙二醇（MCPD）的新方法。在进行高效液相色谱-串联质谱（HPLC-MS）分析之前，使用-（二甲基氨基）苯酚对这些化合物进行衍生化，从而能够灵敏地测定这些污染物。样品制备程序包括使用氯化钠水溶液萃取和C18吸附剂净化（用于破乳）进行简单、高效的预处理，在不同的衍生化反应条件（弱酸性和强碱性水环境）下区分缩水甘油和MCPD。该方法在1至至少256 ng·mL范围内具有广泛的线性，与标准气相色谱-质谱（GC-MS）方法相比灵敏度有所提高，两种油样中MCPD和缩水甘油的检测限（LOD）和定量限（LOQ）分别验证为0.5 ng·mL和1 ng·mL。与以往直接检测缩水甘油酯或MCPD酯的HPLC-MS方法不同，这是首次用于检测食用油中游离缩水甘油和总游离MCPD的HPLC-MS方法。此外，该方法有可能用于缩水甘油或单氯丙二醇酯的检测，类似于目前在不同食品基质中间接检测这些污染物所采用的官方方法。将这种检测方法应用于实际膳食补充剂（鱼油和磷虾油），发现鱼油中存在MCPD残留（最大检测值：32.78 ng·mL），磷虾油中同时存在MCPD（最大检测值：2767.3 ng·mL）和缩水甘油（最大检测值：22.2 ng·mL），强调了其在评估这些补充剂污染方面的有效性和准确性。
