Smallidge R L, Albert K
Office of Indiana State Chemist, Purdue University, West Lafayette 47907-1154, USA.
J AOAC Int. 2000 Mar-Apr;83(2):260-8.
A liquid chromatographic (LC) method for the analysis of sulfamethazine (SMT) in complete swine and cattle feed was collaboratively studied. The method uses post-column derivatization with dimethylaminobenzaldehyde and detection at 450 nm. To 5g finely ground feed, extractant (0.2N HCl + 1.5% diethylamine in 25% methanol), and internal standard solutions are added, and the SMT is extracted by shaking for 1 h. Clarified extract (high-level sample extract diluted to a target concentration of ca 5.5 microg/mL) is chromatographed on a Cla reversed-phase LC column with acetonitrile-2% acetic acid (17 + 83) mobile phase. Sulfamerazine is used as an internal, or surrogate standard to correct for variable recovery of sulfamethazine from a variety of feed matrixes. Six Youden matched-pair samples were sent to 10 collaborators in Korea, Canada, and the United States. Label claims on the commercial feeds ranged from 0.0077 to 0.22% SMT. The SMT mean recovery as determined from the 5 samples with known analyte content was 99.8%. The within-laboratory relative standard deviation (repeatability) ranged from 0.28 to 4.72%. Among-laboratory (including within-laboratory) relative standard deviation (reproducibility) ranged from 1.26 to 4.87%. The authors recommend the method for AOAC INTERNATIONAL Official First Action status.
对一种用于分析全价猪饲料和牛饲料中磺胺二甲嘧啶（SMT）的液相色谱（LC）方法进行了协同研究。该方法采用与二甲基氨基苯甲醛的柱后衍生化，并在450nm处进行检测。向5g精细研磨的饲料中加入萃取剂（0.2N盐酸 + 25%甲醇中的1.5%二乙胺）和内标溶液，通过振荡1小时萃取SMT。澄清的萃取液（将高浓度样品萃取液稀释至目标浓度约5.5μg/mL）在Cla反相LC柱上进行色谱分析，流动相为乙腈 - 2%乙酸（17 + 83）。磺胺甲嘧啶用作内标或替代标准，以校正从各种饲料基质中回收磺胺二甲嘧啶时的可变回收率。六个尤登匹配对样品被分发给韩国、加拿大和美国的10位合作者。商业饲料上的标签声明的SMT含量范围为0.0077%至0.22%。从5个已知分析物含量的样品中测定的SMT平均回收率为99.8%。实验室内相对标准偏差（重复性）范围为0.28%至4.72%。实验室间（包括实验室内）相对标准偏差（再现性）范围为1.26%至4.87%。作者建议将该方法作为AOAC INTERNATIONAL官方首次行动状态的方法。
