Fan Jing, Wang Aijun, Feng Suling, Wang Jianji
Henan Key Laboratory for Environmental Pollution Control, School of Chemical and Environmental Sciences, Henan Normal University, Xinxiang 453007, PR China.
Talanta. 2005 Mar 31;66(1):236-43. doi: 10.1016/j.talanta.2004.11.020. Epub 2004 Dec 25.
A new sequential injection spectrophotometric method was proposed for the determination of metoclopramide and tetracaine hydrochloride. The method was based on the detection of an unstable red intermediate compound resulting from the reaction of metoclopramide or tetracaine hydrochloride with potassium dichromate, in the presence of sodium oxalate, in sulfuric acid solution. The related reaction mechanisms of this new method have been studied. The experimental conditions were optimized for the stopped-flow and continuous-flow sequential injection models. For continuous flow, the linear range for determination of metoclopramide, the detection limit and the sampling frequency were 13-130 microgml(-1), 9.4 microgml(-1) and 40 samples per hour, respectively. For stopped flow, they were 3-42 microgml(-1), 1.0 microgml(-1) and 18h(-1), respectively. Adopting the continuous-flow model for tetracaine hydrochloride, the linear range was 25-300 microgml(-1), and the detection limit was 18.0 microgml(-1) with sampling frequency of 40h(-1). This method has been used to determine metoclopramide and tetracaine hydrochloride in pharmaceutical preparations, and the results are compared with those determined by the pharmacopoeia method. Statistical analysis reveals that there was no evidence of significant difference between the methods.
提出了一种新的顺序注射分光光度法用于测定甲氧氯普胺和盐酸丁卡因。该方法基于在硫酸溶液中，在草酸钠存在下，甲氧氯普胺或盐酸丁卡因与重铬酸钾反应生成的不稳定红色中间化合物的检测。研究了该新方法的相关反应机理。针对停流和连续流顺序注射模型对实验条件进行了优化。对于连续流，甲氧氯普胺测定的线性范围、检测限和采样频率分别为13 - 130 μgml(-1)、9.4 μgml(-1)和每小时40个样品。对于停流，它们分别为3 - 42 μgml(-1)、1.0 μgml(-1)和18 h(-1)。采用连续流模型测定盐酸丁卡因，线性范围为25 - 300 μgml(-1)，检测限为18.0 μgml(-1)，采样频率为40 h(-1)。该方法已用于测定药物制剂中的甲氧氯普胺和盐酸丁卡因，并将结果与药典方法测定的结果进行了比较。统计分析表明，两种方法之间没有显著差异的证据。
