采用高效液相色谱-串联质谱法测定生鲜乳中三聚氰胺残留量.样品经乙腈溶液超声提取,过Waters Oasis MCX固相萃取小柱净化,50 ℃氮气吹干,再用1.0 mL乙腈溶解后供高效液相色谱-串联质谱分析.以Waters Hilic色谱柱(100 mm×2.1 mm,3 μm)为固定相,用乙腈-5 mmol·L-1乙酸铵(95+5)溶液洗脱,采用电喷雾正离子模式多反应监测,内标法定量.三聚氰胺的质量浓度在10.0 μg·L-1以内呈线性,检出限(3S/N)为0.5 μg·kg-1.取空白样品在3个标准加入水平下进行回收和精密度试验,回收率在99.8%~103%之间,测定值的相对标准偏差(n=10)在1.9%~3.2%之间.

HPLC-MS/MS was applied to measure melamine residue in milk. The sample was extracted with acetonitrile-water,purified by Waters Oasis MCX solid phase extraction column,dried by nitrogen at 50 ℃,dissolved with 1 mL of acetonitrile and used for HPLC-MS/MS analysis. Waters Hilic column (100 mm×2.1 mm,3 μm) was used as stationary phase,and a mixture (95+5) of acetonitrile and 5 mmol·L-1 of ammonium acetate as mobile phase. ESI+ and MRM were adopted in MS/MS. Internal standard method was used for quantization. Linearity range of melamine was within 10.0 μg·L-1,the detection limit (3S/N) was 0.5 μg·kg-1. Tests for recovery and precision were made by addition of melamine,giving values of recovery in the range of 99.8%-103% and values of RSD′s (n=10) in the range of 1.9%-3.2%.