采用反吹技术和GC-MS/MS测定婴幼儿奶粉及乳制品中三聚氰胺

Determination of melamine in infant milk powder and dairy containing products by backflushing technique and GC-MS/MS

目的建立反吹技术和三重串联四极杆气相色谱-质谱法测定婴幼儿奶粉及乳制品中三聚氰胺。方法样品用甲醇水溶液超声提取,离心后用微孔滤膜过滤,无需固相萃取柱净化,氮气吹干,硅烷化衍生,采用反吹技术和三重串联四极杆气相色谱质谱分析,多反应监测模式检测,外标法定量。结果在1 ng^50 ng时线性良好(r=0.999),在100μg/kg、500μg/kg添加水平回收实验时,回收率为89.2%~103%,相对标准偏差为5.07%和2.90%,检出限为0.25 ng(S/N≥3),样品最终检出限为12μg/kg。结论该方法样品处理简便、快速、灵敏、准确,对仪器检测器有保护,适合婴幼儿奶粉及乳制品中三聚氰胺的测定。

Objective To develop a method for determination of melamine in infant milk powder and dairy containing products.Methods The sample was analyzed with gas chromatograph coupled to a triple quadrupole mass spectrometry with backflushing controlled by electronic pressure control devices,and monitored by multiple reaction monitoring mode The sample was extracted with methanol. The extracted solution was evaporated to dryness under a stream of nitrogen and then converted to trimethylsilyl derivatives,determined by GC- MS / MS with backflushing technique. Results The linear range was good between 1 ng-50 ng. In the recovery experiment added 100 μg / kg,500 μg / kg,the recoveries were 89. 2%- 103%,and the relative standard deviation was 5. 07% and 2. 90%; The limit of detection was 0. 25 ng（ S / N≥3） and the ultimate limit of was 12 μg / kg.Conclusion The method is simple,sensitive,fast,and accurate and it can also protect the equipment. This method is suitable for the determination of melamine in infant milk powder and dairy containing products.