液质联用检测奶茶中三聚氰胺基质效应的研究及消除

Study and Elimination of Matrix Effect of Melamine in Ice Cream and Milk Tea by LC-MS

选取8种不同品牌的奶茶,研究液相色谱-串联质谱测定奶茶中三聚氰胺基质效应的影响因素及其消除方法,试验研究了取样量、溶剂种类、溶剂用量、不同浓度三聚氰胺、净化方式等影响基质效应的因素。结果表明取样量、溶剂种类[除三氯乙酸与三氯乙酸-乙腈4∶1 (V/V)之间外]、溶剂用量、净化方式(过SPE小柱和不过SPE小柱之间)存在显著的基质效应,其余皆无显著性基质效应;通过内标法可消除在检测三聚氰胺过程中的基质效应,内标法测定三聚氰胺在加标质量分数为25, 50和100μg/kg水平上回收率为101.8%~107.9%,精密度为0.8%~106%。

Eight diferent kinds of milk tea were selected to study the influencing factors of matrix effect and its elimination in the determination of melamine in milk tea by liquid chromatography tandem mass spectrometry.The relationship between matrix effect and sampling amount,solvent type,solvent dosage,different concentrations of melamine and purification method were investigated There were significant differences in the types of solvents[except trichloroacetic acid and trichloroacetic acid-acetonitrile 4:1(V/V)],the amount of solvents and the purification methods(between the SPE column and the SPE column).The rest had no significant matrix effect;The matrix effect in the detection of melamine could be eliminated by internal standard method.The recovery rate of melamine determined by internal standard method was 101.8%-107.9%and the precision was 0.8%-106%at the spiked concentrations of 25,50 and 100μg/kg.