兽药粉剂/预混剂中甲氧苄啶的测定

Determination of Trimethoprim in Powder/Premix of Veterinary Drug

本文建立了HPLC测定兽药粉剂／预混剂中甲氧苄啶含量的方法。采用Watem C18色谱柱（150mm×4．6mm，5μm），流动相为甲醇-20mmol／L磷酸二氢钾溶液（20：80），流速1·0mL／min，检测波长为271nm，进样量为10μL。含量测定的线性范围为10～250μg／mL，r=1·0（n=6）；甲氧苄啶的加样回收率在99．38％～100．6％之间；最低检出浓度为0．25μg／mL。结果表明本法简便、快速、准确、重复性好。

A method to determine the contents of trimethoprim in powder/premix of veterinary drug by HPLC was established. The optimal chromatographic parameters were decided： chromatographic column was Waters C18 （150 mm ×4.6 mm,5 μm）, trimethoprim were measured at 271 nm with methanol-20mmol · L^-1 potassium dihydrogen phosphate（20： 80） as the mobile phase, and the flow of rate was 1.0 mL/min. On these conditions, the peak area is used for quantification in external method, the linear ranges were 10 -250 μg/mL（ r = 1.0,n =6） ; the recovery was 99.38% ～ 100.6% ; the limit of detection was 0.25 μg/mL. The method is rapid, convenient and accurate.