Vinjamoori D V, Schisla R M
J Assoc Off Anal Chem. 1986 May-Jun;69(3):474-7.
Capillary isotachophoresis, which involves the separation of charged species under an electric field, has been applied to the rapid determination of 2-hydroxy-4-(methylthio)butanoic acid at 0.04-0.50% concentration levels in corn/soy-based poultry feeds, using conductivity detection. The procedure merely involves a 15 min cold water extraction of the sample and a 15 min analysis after injection of the filtrate into the instrument. Since only charged species migrate and non-ionic species stay virtually at the front of the column, extraordinary selectivity can be achieved. The isotachophoresis method is an order of magnitude faster than the gas chromatographic method reported recently and also provides information on HMB-monomer/dimer ratio in the same run. The sample recoveries exceeded 90% in all concentration ranges studied with coefficients of variation less than +/- 10%.
毛细管等速电泳涉及在电场下对带电物质进行分离，它已被应用于快速测定玉米/大豆基家禽饲料中浓度为0.04 - 0.50%的2 - 羟基 - 4 - （甲硫基）丁酸，采用电导检测法。该方法仅需对样品进行15分钟的冷水萃取，将滤液注入仪器后进行15分钟的分析。由于只有带电物质迁移，而非离子物质几乎停留在柱前端，因此可实现极高的选择性。等速电泳法比最近报道的气相色谱法快一个数量级，并且在同一次运行中还能提供关于HMB单体/二聚体比例的信息。在所研究的所有浓度范围内，样品回收率均超过90%，变异系数小于±10%。
