高效液相色谱-质谱联用法测定乳品中的左旋肉碱

Determinatin of L-carnitine in milk products by high performance liquid chromatography-tandem mass spectrometry

目的建立高效液相色谱串联质谱法测定乳品中左旋肉碱的含量。方法样品中的左旋肉碱用乙腈水(3:1,V:V)溶液提取,提取液经碱皂化后使溶液中结合态的左旋肉碱游离出来。提取液经酸液中和后,高速离心去除杂质,取上清液并用微孔滤膜过滤,稀释后用高效液相色谱-质谱联用仪进行测定和确证。结果待测物质在2~100 ng/m L范围内呈良好的线性关系(r2=0.9941),左旋肉碱在不同基质中的加标回收率为66.3%~110.5%,精密度为2.0%~8.8%。结论此法可满足日常进出口乳品中左旋肉碱含量的测定工作,同其他方法相比具有准确定性、操作简单、省时高效的特点。

ABSTRACT:Objective To establish a method for the detection ofL-carnitine in milk products by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS).MethodsL-carnitine in samples was extracted by acetonitrile:water (3:1, V:V) solution. The combinedL-carnitine was released by alkaline saponification. After neutralized by acid, the extraction was centrifuged to discard impurity. Then superna-tant was filtered by syringe filter (0.2μm) and diluted. Finally, the sample was measured by HPLC-MS/MS. ResultsIt showed a good linearity of material in 2~100 ng/mL (r2=0.9941). The recoveries ofL-carnitine in different matrix were 66.3%~110.5%, with the precision of 2.0%~8.8%.ConclusionThis method can meet the daily inspection work of import and export ofL-carnitine in milk products. Compared with other methods, it has the characteristics of exact determination, simple operation, time saving and high efficiency.