提出了应用GB/T 22400-2008的条件测定饲料中三聚氰胺含量的方法,避免了在更换色谱柱及流动相的操作.色谱条件:SCX色谱柱(250 mm×4.6 mm,5 μm)作固定相,流动相为pH 3.0的磷酸二氢钾溶液与乙腈的混合液(7+3,体积比),洗脱时,流量为1.0 mL·min-1,检测波长为240 nm,柱温30 ℃.三聚氰胺的质量浓度在0.5~10.0 mg·L-1范围内呈线性,方法检出限(3S/N)为2.0 mg·kg-1.在2.0,5.0,10.0 mg·kg-1的浓度水平将标准溶液加入于同一样品基体中进行回收及精密度试验,测得平均回收率为78.8%~80.1%之间,相对标准偏差(n=6)小于8.10%.

Condition used in the GB/T 22400-2008 were applied to the analysis of feed for its melamine content,thus avoiding the operation of changing chromatographic column and mobile phase.The SCX column (250 mm×4.6 mm,5 μm) was used as stationary phase (column temp: 30 ℃),and a mixture of KH2PO4 buffer solution of pH 3.0 and acetonitrile (mixed in the ratio of 7 to 3 by vol.) was used as mobile phase in the elution at the flow-rate 1.0 mL·min-1.UV detection with DAD at the wavelength of 240 nm was adopted in the determination.Range of linearity for melamine was found between 0.5 mg·L-1 and 10.0 mg·L-1.Detection limit (3S/N) found was 2.0 mg·kg-1.Recovery and precision were tested at 3 concentration levels of 2.0,5.0,10.0 mg·kg-1,by addition of standard melamine solution to a same matrix sample.Values of average recovery found were in the range of 78.8% to 80.1% with values of RSD′s (n=6) less than 8.10%.