Ozaltin Nuran, Yardimci Ceren, Süslü Incilay
Department of Analytical Chemistry, Faculty of Pharmacy, Hacettepe University, 06100, Sihhiye, Ankara, Turkey.
J Pharm Biomed Anal. 2002 Oct 15;30(3):573-82. doi: 10.1016/s0731-7085(02)00311-4.
A simple, sensitive and selective square-wave adsorptive stripping voltammetric method has been developed and validated for the determination of nifedipine (NIF) in plasma. The assay was performed after single extraction of NIF from alkalinised plasma into organic phase. The adsorption behaviour of NIF on a hanging mercury drop electrode (HMDE) was explored by square-wave and cyclic voltammetry. The drug was accumulated at HMDE and a well-defined peak was obtained at -730 mV versus Ag/AgCl in borate buffer of pH 9.0 including 0.01 M KCl. The linear concentration range was 2.89 x 10(-9) M-3.61 x 10(-7) M (1.00-125.01 ng ml(-1)) when using 30 s accumulation time at -300 mV. Limit of detection and limit of quantification were 1.21 x 10(-9) M (0.42 ng ml(-1)) and 2.89 x 10(-9) M (1.00 ng ml(-1)) respectively. The intra-day relative standard deviation (RSD) ranged from 1.93 to 4.12% at three concentrations and the inter-day RSDs varied from 2.53 to 6.68%. The method was applied, to the plasma of pregnant women suffering from pregnancy induced hypertension, for the determination of NIF. The percentage recoveries varied from 96.26 to 99.49%. It has been shown that NIF could be determined in the presence of its main metabolite (dehydronifedipine) by the developed method.
已开发并验证了一种简单、灵敏且具选择性的方波吸附溶出伏安法，用于测定血浆中的硝苯地平（NIF）。该测定在将NIF从碱化血浆单次萃取至有机相后进行。通过方波和循环伏安法探究了NIF在悬汞滴电极（HMDE）上的吸附行为。药物在HMDE上富集，并在pH 9.0含0.01 M KCl的硼酸盐缓冲液中相对于Ag/AgCl在-730 mV处获得一个清晰的峰。当在-300 mV处采用30 s富集时间时，线性浓度范围为2.89×10⁻⁹ M - 3.61×10⁻⁷ M（1.00 - 125.01 ng ml⁻¹）。检测限和定量限分别为1.21×10⁻⁹ M（0.42 ng ml⁻¹）和2.89×10⁻⁹ M（1.00 ng ml⁻¹）。日内相对标准偏差（RSD）在三个浓度下为1.93%至4.12%，日间RSD在2.53%至6.68%之间变化。该方法应用于患有妊娠高血压综合征的孕妇血浆中NIF的测定。回收率在96.26%至99.49%之间。结果表明，所开发的方法可在其主要代谢物（脱氢硝苯地平）存在的情况下测定NIF。
