气相色谱-质谱法测定乳制品中的硫氰酸根

利用气相色谱-质谱联用仪对乳制品(主要指液体乳及乳粉)中硫氰酸根残留量进行测定。根据硫氰酸根能与α-溴-2,3,4,5,6-五氟甲苯(PFB.Br)上的活泼溴发生取代反应的原理,试样采用振荡提取后进行衍生,高速冷冻离心,衍生产物采用选择离子监测质谱扫描,用化合物的保留时间以及质谱碎片的丰度比定性,外标法定量。结果表明:在定量检测范围为0.02～50.0mg/kg范围之内,回收率、灵敏度高,准确性与重现性良好。该方法前处理简单、易操作、成本低、分析周期短,可作为液体乳与乳粉中硫氰酸钠的快速检测方法。

Determination of Thiocyanate in Milk and Milk Powder by Gas Chromatography-Mass Spectrometry

Gas chromatography-mass spectrometry was used to determine thiocyanate residues in dairy products(mainly liquid milk and milk powder).Samples were extracted by shaking before derivatization based on the replacement reaction of pentafluorobenzyl bromide with thiocyanate.The derivatization products were separated using a high-speed refrigerated centrifuge and scanned in the selected ion monitoring mode.Thiocyanate was qualified based on retention time and ion abundance ratio and quantified by external standard method.High recovery,sensitivity,accuracy and reproducibility were found in the quantitative range of 0.02-50.0 mg/kg.The method was characterized by simple pretreatment,easy operation,low cost and time saving,and applicable for the rapid determination of thiocyanate residues in dairy products.