Two‐step liquid phase microextraction combined with capillary electrophoresis: A new approach to simultaneous determination of basic and zwitterionic compounds

Abstract

In this work, two-step hollow fiber-based liquid-phase microextraction procedure was evaluated for extraction of the zwitterionic cetirizine (CTZ) and basic hydroxyzine (HZ) in human plasma. In the first step of extraction, the pH of sample was adjusted at 5.0 in order to promote liquid-phase microextraction of the zwitterionic CTZ. In the second step, the pH of sample was increased up to 11.0 for extraction of basic HZ. In this procedure, the extraction times for the first and the second steps were 30 and 20 min, respectively. Owing to the high ratio between the volumes of donor phase and acceptor phase, CTZ and HZ were enriched by factors of 280 and 355, respectively. The linearity of the analytical method was investigated for both compounds in the range of 10-500 ng mL(-1) (R(2) > 0.999). Limit of quantification (S/N = 10) for CTZ and HZ was 10 ng mL(-1) , while the limit of detection was 3 ng mL(-1) for both compounds at a signal to noise ratio of 3:1. Intraday and interday relative standard deviations (RSDs, n = 6) were in the range of 6.5-16.2%. This procedure enabled CTZ and HZ to be analyzed simultaneously by capillary electrophoresis.

D‐Optimal mixture design optimization of an HPLC method for simultaneous determination of commonly used antihistaminic parent molecules and their active metabolites in human serum and urine

“…The method required an additional precolumn florescence labeling reaction for analyte detection. Nojavan, Moharami, and Fakhari () reported a capillary electrophoresis method for simultaneous determination of HYD and CTZ in human plasma. The method employed a time‐consuming extraction procedure taking ~30 min.…”

Preparation of poly(glycidylmethacrylate‐divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride, phthalic anhydride, and maleic anhydride for ion chromatography

“…The determination of these compounds can provide important information about inherited or acquired metabolic disorders. And most utilized methods for the assay of them are based on separation techniques, especially chromatography . IC method with nonsuppressed conductivity detection has been developed to determine the zwitterionic compounds as they show positive electrical property in acidic conditions .…”

Separation and identification of cetirizine enantiomers in human urine by capillary electrophoresis and circular dichroism independent of their standards

“…As shown in Figure 1, cetirizine has three ionizable functions, namely a weak acidic group (pK a = 3.57), a strong basic group (pK a = 7.56), and a weak basic group (pK a = 2.70) [28]. According to the acid-base behavior and pH distribution curve in different solvent systems, cetirizine can be considered a zwitterionic compound at a pH value range of 3.57−7.56 theoretically [29,30]. A number of electrophoretic and chromatographic analytical methods for the separation and quantification of cetirizine can be found in the literatures [27,[31][32][33][34][35][36].…”