超高效液相色谱-串联质谱法测定奶粉中的三聚氰酸

建立奶粉中的三聚氰酸的超高效液相色谱-四极杆串联质谱(UPLC-MS/MS)检测方法。样品经透析袋净化、反相液相色谱分离后进行质谱分析，在多反应监测模式(MRM)下进行特征母-子离子对信号采集。根据保留时间、母离子和两个特征子离子信息进行定性分析，以离子对m/z 42.0进行定量。三聚氰酸的最低检测限(RSN=3)为100.0μg/kg。在100.0～2000.0μg/L时峰强度与质量浓度的线性关系良好(r2≥0.9999)。在100.0、500.0、1000.0μg/kg 3个添加水平，三聚氰酸的回收率范围为87.5%～98.8%，相对标准偏差小于9%。结果表明，该法简单、灵敏，适用于奶粉中三聚氰酸的分析确证。

Determination of Cyanuric Acid in Milk Powder by UPLC-MS/MS

An ultra-high performance liquid chromatography-quadrupole tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of cyanuric acid residues in milk powder. Samples were thoroughly suspended in 60 ℃ water and dialyzed against deionized water for 3 h in 60 ℃ water bath before analysis on reversed-phase high performance liquid chromatography-quadrupole tandem mass spectrometry. Mass spectral acquisition was applied with a multiple reaction-monitoring (MRM) mode. Qualitative analysis was achieved on the basis of the retention time and information about parent ions and two daughter ions. Quantitative determination was carried out on the basis of the characteristic ion of m/z 42.0. The linear range for cyanuric acid was between 5μg/L and100μg/L with a correlation coefficients (r2) of larger than 0.9999. The average recovery rate for cyanuric acid ranged between 87.5% and 98.8% in milk powder samples spiked at the levels of 100.0, 500.0 μg/kg and 1000.0μg/kg. The relative standard deviation (RSD) was less than 9%. The detection limit of this method was 100.0μg/kg. Therefore, this method is simple and suitable for routine analysis of milk powder.