高效液相色谱法快速测定奶粉中三聚氰胺的含量

目的: 建立快速样品预处理和高效液相色谱法测定奶粉中三聚氰胺含量的方法。 方法: 样品预处理采用1%甲酸水溶液为脱脂剂,乙腈为沉淀剂,快速处理样品;含量分析采用高效液相色谱法,色谱柱为C₁₈预柱＋CAPCELL PAK CR(1∶ 4)柱(3.0 mm×150 mm,5 μm),流动相:含1%醋酸的0.025 mol·L^-1醋酸铵溶液-乙腈(50∶ 50),流速:0.5 mL·min^-1 ,检测波长:240 nm,柱温:40 ℃。 结果: 样品预处理简便快捷;三聚氰胺的线性范围为0.20~50.00 mg·L^-1(r=0.9999),3个水平回收率均在97%~103%之间,方法检测限为0.2 mg·kg^-1 ,定量限为0.6 mg·kg^-1 。 结论: 该方法快速、灵敏、准确、重复性好,可用于奶粉中三聚氰胺的分析测定。

Objective: To develop a method for the extraction and determination of melamine in milk power by HPLC. Method: The chromatographic separation was achieved on C₁₈ pre-column and CAPCELL PAK CR (1∶ 4) colunm(3.0 mm×150 mm,5 μm)with 0.025 mol·L^-1 ammonium acetate containing 1% acetic acid – acetonitrile(50∶ 50) as the mobile phase at a flow rate of 0.5 mL·min^-1 .The column was maintained at 40 ℃ and the detective wavelength was 240 nm. Results: The calibration curve was linear in the range of 0.20-50.00 mg·L^-1 for melamine (r=0.999 9)and the average recoveries (n=3) are 97% 103%.The limits of detection (LOD) and the limits of quantitation(LOQ) were 0.2 mg·kg^-1 and 0.6 mg·kg^-1 ,respectively. Conclusion: The method is rapid,sensitive,accurate,reproducible and can be used in the rapid determination of melamine in milk power.