Xia Xi, Ding Shuangyang, Li Xiaowei, Gong Xiao, Zhang Suxia, Jiang Haiyang, Li Jiancheng, Shen Jianzhong
Department of Pharmacology and Toxicology, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Anal Chim Acta. 2009 Oct 5;651(2):196-200. doi: 10.1016/j.aca.2009.08.025. Epub 2009 Aug 25.
A sensitive and reliable method was developed and validated for detection and confirmation of melamine in egg based on gas chromatography-mass spectrometry (GC-MS) and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Trichloroacetic acid solution was used for sample extraction and precipitation of proteins. The aqueous extracts were subjected to solid-phase extraction by mixed-mode reversed-phase/strong cation-exchange cartridges. Using ultra-performance liquid chromatography and electrospray ionization in the positive ion mode, melamine was determined by LC-MS/MS, which was completed in 5 min for each injection. For the GC-MS analysis, extracted melamine was derivatized with N,O-bis(trimethylsilyl)trifluoracetamide prior to selected ion monitoring detection in electron impact mode. The average recovery of melamine from fortified samples ranged from 85.2% to 103.2%, with coefficients of variation lower than 12%. The limit of detection obtained by GC-MS and UPLC-MS/MS was 10 and 5 microg kg(-1), respectively. This validated method was successfully applied to the determination of melamine in real samples from market.
建立并验证了一种灵敏可靠的方法，用于基于气相色谱 - 质谱联用（GC-MS）和超高效液相色谱 - 串联质谱联用（UPLC - MS/MS）检测和确证鸡蛋中的三聚氰胺。采用三氯乙酸溶液进行样品提取和蛋白质沉淀。水提取物通过混合模式反相/强阳离子交换柱进行固相萃取。使用超高效液相色谱和正离子模式下的电喷雾电离，通过LC - MS/MS测定三聚氰胺，每次进样5分钟即可完成。对于GC - MS分析，提取的三聚氰胺在电子轰击模式下进行选择离子监测检测之前，先用N，O - 双（三甲基硅基）三氟乙酰胺进行衍生化。加标样品中三聚氰胺的平均回收率在85.2%至103.2%之间，变异系数低于12%。GC - MS和UPLC - MS/MS获得的检测限分别为10和5微克/千克。该验证方法成功应用于市售实际样品中三聚氰胺的测定。
