Nelson K, Woodcock B G, Kirsten R
Int J Clin Pharmacol Biopharm. 1979 Oct;17(10):375-9.
An improvement in the extraction procedure for the quantitative determination of verapamil in human plasma is described. The advantages are: 1. the time involved in the extraction procedure is only 1/3 of that in the original method allowing the extraction of 100 samples in a working day. 2. increased mean recovery from 67% to 85% over the range of 3--90 ng verapamil/ml plasma. 3. less expenditure a) use of cheap plastic tubes instead of stoppered glass tubes. b) 1/2 the amount of heptane required as compared to the original procedure. c) use of air instead of N2 for evaporation. The lower limit of detection is 3 ng/ml which is comparable to that for the original extraction procedure. Within-batch precision over the range of 9--90 ng/ml averages 5.8% and at the lower limit of detection 17.3%. Between-batch precision over the range of 9--90 ng/ml averages 8.5% and at the lower limit of detection 19.7%. No significant difference could be found in the quantitative determination of verapamil in 27 plasma samples from patients undergoing verapamil treatment using the original and modified extraction procedures. This improvement of the extraction procedures simplifies the determination of verapamil and the only additional material required is liquid nitrogen or a suitable solvent cooled with dry ice.
本文描述了一种用于定量测定人血浆中维拉帕米的提取方法的改进。其优点如下：1. 提取过程所需时间仅为原方法的三分之一，一个工作日内可提取100个样本。2. 在3 - 90 ng维拉帕米/毫升血浆范围内，平均回收率从67%提高到85%。3. 成本降低：a) 使用便宜的塑料管代替带塞的玻璃管；b) 与原方法相比，庚烷用量减少一半；c) 使用空气代替氮气进行蒸发。检测下限为3 ng/ml，与原提取方法相当。在9 - 90 ng/ml范围内，批内精密度平均为5.8%，在检测下限为17.3%。在9 - 90 ng/ml范围内，批间精密度平均为8.5%，在检测下限为19.7%。使用原提取方法和改进后的提取方法对27例接受维拉帕米治疗患者的血浆样本进行维拉帕米定量测定，未发现显著差异。这种提取方法的改进简化了维拉帕米的测定，唯一额外需要的材料是液氮或用干冰冷却的合适溶剂。
