Lara Francisco J, García-Campaña Ana M, Alés-Barrero Fermín, Bosque-Sendra Juan M
Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Granada, Spain.
Electrophoresis. 2005 Jun;26(12):2418-29. doi: 10.1002/elps.200500098.
A capillary zone electrophoresis (CZE) method with ultraviolet-visible detection has been established and validated for the determination of five phenothiazines: thiazinamium methylsulfate, promazine hydrochloride, chlorpromazine hydrochloride, thioridazine hydrochloride, and promethazine hydrochloride in human urine. Optimum separation was obtained on a 64.5 cm x 75 microm bubble cell capillary using a buffer containing 150 mM tris(hydroxymethyl)aminomethane and 25% acetonitrile at pH 8.2, with temperature and voltage of 25 degrees C and 20 kV, respectively. Naphazoline hydrochloride was used as an internal standard. Field-amplified sample injection (FASI) has been applied to improve the sensitivity of the detection. Considering the influence of parameters affecting the on-line preconcentration (nature of preinjection plug, sample solvent composition, injection times, and injection voltage) and due to the significant interactions among them, in this paper we propose for the first time the application of a multivariate approach to carry out the study. The optimized conditions were as follows: preinjection plug of water for 7 s at 50 mbar, electrokinetic injection for 40 s at 6.2 kV, and 32 microm of H3PO4 in the sample solvent. Also, a solid-phase extraction (SPE) procedure is developed to obtain low detection limits and an adequate selectivity for urine samples. The combination of SPE and FASI-CZE-UV allows adequate linearities and recoveries, low detection limits (from 2 to 5 ng/mL), and satisfactory precisions (3.0-7.2% for an intermediate RSD %).
已建立并验证了一种采用紫外可见检测的毛细管区带电泳（CZE）方法，用于测定人尿中的五种吩噻嗪类药物：甲硫酸噻嗪铵、盐酸丙嗪、盐酸氯丙嗪、盐酸硫利达嗪和盐酸异丙嗪。在一根64.5 cm×75 μm气泡池毛细管上，使用含150 mM三（羟甲基）氨基甲烷和25%乙腈、pH值为8.2的缓冲液，温度为25℃，电压为20 kV时，可实现最佳分离。使用盐酸萘甲唑啉作为内标。采用场放大进样（FASI）来提高检测灵敏度。考虑到影响在线预富集的参数（预进样塞的性质、样品溶剂组成、进样次数和进样电压）的影响，且由于它们之间存在显著相互作用，本文首次提出应用多变量方法进行研究。优化条件如下：在50 mbar下用7 s水作为预进样塞，在6.2 kV下电动进样40 s，样品溶剂中含32 μM磷酸。此外，还开发了一种固相萃取（SPE）方法，以获得低检测限并对尿样具有足够的选择性。SPE与FASI-CZE-UV联用可实现足够的线性和回收率、低检测限（2至5 ng/mL）以及令人满意的精密度（中间精密度相对标准偏差为3.0 - 7.2%）。
