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EN
In this work, a novel, simple, and quick capillary zone electrophoresis (CZE) method was proposed for simultaneous analysis of benazepril (BEN) with other co-administrated antihypertensive drugs, amlodipine besylate (AML) and hydrochlorothiazide (HCT), using a diode array detector (DAD). A fused silica capillary (78.5 cm total length, 70 cm effective length, and 75 μm id) was used in separation using a 40 mM phosphate buffer pH 7.5 as a running background electrolyte (BGE) under a positive potential of 30 KV, at a stable temperature of 25 °C for capillary during separation. Hydrodynamic injections were performed for 12 s at 50 mbar, and detection was performed at 210 nm for AML and BEN, at 225 nm for HCT, and at 232 nm for xipamide (XIP) added as an internal standard (IS). Separation of the three analyzed drugs and the IS was performed in less than 8 min. Migration times were 4.06, 5.23, 6.69, and 7.3 min for AML, HCT, BEN, and XIP, respectively. The findings proved that the proposed method was linear in the range of 10–80 μg/mL for all drugs with correlation coefficients >0.9994. The limit of detection (LOD) values of AML, HCT, and BEN were 1.004, 1.224, and 0.896 μg/mL, respectively, whereas the limit of quantification (LOQ) values were 3.124, 3.727, and 2.749 μg/mL for the cited drugs, respectively. Peak identity and purity were confirmed by DAD. The developed CZE method was applied for the analysis of the three antihypertensive drugs successfully in their combined pharmaceutical tablets, and it can be used for the quality control of single-pill combination (SPC) samples of these drugs in short time.
EN
Electrical properties of biocolloids, due to the unique structure and properties of the walls and cell membranes are altered by ions present in the environment. This change in the surface properties of bacterial cells has a major impact on the effects of cell-cell or cell-surface during the formation of aggregates or biofilm. Each microorganism has a complex and characteristic cell wall composition, which surface charge originates from the ionization of carboxyl, phosphate or amino groups and the adsorption of ions from solution. Consequently, the charged cell wall groups determine the spontaneous formation of the electrical double layer (EDL). The properties of the EDL affect the behavior of biocolloid including cell-to-cell and cell-to-capillary surface interactions. In addition, the inner wall surface of capillary groups (modified and/or unmodified) interact with the solvent and the analyte. Biocolloids effect of aggregation and adhesion to the surface of the capillary is unfavorable phenomenon occurring during the electrophoretic separation. These phenomena are highly correlated with the acid-base properties of the bacterial cells. Interactions between molecules are unstable, hence the analytes adsorbed on the surface concerned can be removed using a variety of solvents or physico-chemical and mechanical factors. However, when the bacterial cells are in close proximity to the charged surface of the capillary may be subject to specific and non-specific short-range interactions, which are characterized by high stability. It has been shown the characteristics of the microbial surface in order to determine their role in adhesion and aggregation phenomena during the electrophoretic separation. The use of experimental techniques, including instrumental, electrochemical and electrophoretic allowed the description of the relationship between the acid-base properties of pathogens and their behavior. The review summarizes the research on biocolloids which are helpful in understanding the interactions that occur during electrophoretic analysis.
EN
Bis(salicylaldehyde) orthophenylenediamine (BSOPD) is reported here as a complexing reagent for simultaneous determination of six metal ions, gold, chromium, iron(II)/(III), uranyl, and nickel, by capillary zone electrophoresis. The pre-derivatized complexes were injected onto 50 cm bare silica capillary (i.d. 75 µm) with background electrolyte 50 mM citrate:oxalate buffer in 1:1 at pH 4. All metal ions were separated within 15 min including coexisted ions at applied voltage of −15 kV at detection wavelength of 250 nm. Under the abovementioned conditions, limits of quantification and detection were found to be 0.5, 1.0, 1.0, 10.0, 1.0, and 10.0 µg mL-1; and 0.16, 0.33, 0.33, 3.33, 0.33, and 3.33 µg mL-1 for Au(III), Cr(VI), Fe(III), Fe(II), UO2(II), and Ni(II), respectively. Linear calibration graphs were obtained in the ranges of 0.5–100, 1–200, 10–100, 1–100, 1–100, and 10–200 µg mL-1 with the correlation coefficient values 0.9964, 0.9948, 0.9900, 0.9999, 0.9992, and 0.9918 for Au(III); and Cr(VI), Fe(III), Fe(II), UO2(II), and Ni(II), respectively. Applicability of the method has been evaluated by determining gold from wastewater samples of goldsmith factories and uranyl from ore samples. The developed method was also used for the determination of chromium in selected environmental waters (drinking and polluted). The data obtained with developed method were compared with those obtained from atomic absorption spectroscopy, and the results of the analysis were found to be in good agreement.
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