Development And Validation Of Online Preconcentration Capillary Electrophoresis Methods For The Determination Of Selected Pharmaceutical Compounds In Aqueous Matrices

In this study, several preconcentration strategies in capillary electrophoresis (CE) were developed to improve the sensitivity of detection of pharmaceutical compound in real aqueous matrices. This is due to the core challenge to develop simple and sensitive analytical method for trace analysis study of selected analytes (anticancer, antibiotic and non-steroidal anti-inflammatory drugs) are very limited. Higher interference level from complex matrix (biological, food and water) with analytical instrument poor detection capability directed to development of online preconcentration technique. The first technique termed sequential injection mode stacking was developed for the separation and determination of anticancer agent 5-fluorouracil (5-FU) and its metabolite namely, 5-fluoro-2-deoxyuridine (5-FdUrd) in human plasma obtained from cancer patients. In this technique, large sample volume was introduced through electrokinetic injection followed by hydrodynamic injection. Under the optimized experimental conditions, 614- and 643- fold and 782- and 803- fold sensitivity improvement was obtained for both 5-FU and its metabolite when compared with normal hydrodynamic and electrokinetic injection alone, respectively

Molecularly imprinted silica gel incorporated with agarose polymer matrix as mixed matrix membrane for separation and preconcentration of sulfonamide antibiotics in water samples

Molecularly imprinted silica gel (MISG) was incorporated through dispersion in agarose polymer matrix to form a mixed matrix membrane (MMM) and was applied for the determination of three sulfonamide antibiotic compounds (i.e. sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ)) from environmental water samples. Several important microextraction conditions, such as type of desorption solvent, extraction time, amount of sorbent, sample volume, pH, and effect of desorption time, were comprehensively optimized. A preconcentration factors of ≥ 20 was achieved by the extraction of 12.5 mL of water samples using the developed method. This microextraction-HPLC method demonstrated good linearity (1–500 μg L–1) with a coefficient of determination (R2) of 0.9959–0.9999, low limits of detection (0.06–0.17 μg L–1) and limits of quantification (0.20–0.56 μg L–1), good analyte recoveries (80–96%), and acceptable relative standard deviations (< 10%) under the optimized conditions. The method is systematically compared to those reported in the literature

Advanced adsorptions of non-steroidal anti-inflammatory drugs from environmental waters in improving offline and online preconcentration techniques : An analytical review

Humans and animals frequently utilize nonsteroidal anti-inflammatory drugs (NSAIDs) as analgesics for various conditions. The ubiquitous use of NSAIDs has resulted in their widespread presence in environmental waters (concentrations detected in water (Malaysia) ranging from 1.40 × 10-1 to 9.72 × 10-2 mg L−1), which may threaten human health. Consequentially, continuous vigilance and resolve are indispensable for preventing any catastrophe. Numerous preconcentration techniques have been developed in response to the rising demand for a rapid, sensitive, and robust method capable of producing a dependable result (relative recoveries (RR) > 70% and limit of detection (LOD) 0.1 ng mL−1). Methods: This review aims to summarize the advancement of pre-concentration techniques using advanced adsorptive materials in quantifying NSAIDs from water mediums. Different univariate and multivariate optimization approaches for offline and online preconcentration are discussed in detail. Significant findings: The multivariate approach is more promising compared to conventional approach for developing an offline preconcentration technique. The analytical performance of online and offline preconcentration is comparable, but online preconcentration utilizes less solvent, aligning with the Green Analytical Chemistry initiative

Simple and sensitive electrokinetic supercharging in capillary electrophoresis for online preconcentration and separation of secbumeton in water samples

This study describes an electrokinetic supercharging for online preconcentration capillary electrophoresis (CE) technique of secbumeton in water samples. Important CE separation and preconcentration conditions, such as concentration and pH of the background electrolyte, applied voltage and ultraviolet wavelength, type and injection time of the terminating electrolyte, and injection time of the leading electrolyte and sample were investigated and optimized. The optimum conditions involved hydrodynamic injection of leading electrolyte (100 mM sodium chloride, 30 s, 50 mbar), electrokinetic injection of the sample as high as 250 s (at +7 kV voltage), and hydrodynamic injection of terminating electrol7te (100 mM Tris buffer, 40 s, 50 mbar). This strategy enhanced secbumeton detection sensitivity up to 3847-fold and 226-fold when compared with hydrodynamic and electrokinetic injection, respectively, providing a limit of detection as low as 0.03 μg L-1with good repeatability (relative standard deviation < 4%, n = 5). Wide linear range (0.1-500 μg L-1) with good linearity (R2= 0.9997) was obtained. The limit of detection was adequate for the analysis of secbumeton in water samples with concentrations lower than its maximum residual limit (0.1 μg L-1). The developed method was applied to environmental water samples, and recoveries were between 85.7 and 105.6%

Induced sample via transient isotachophoresis mediated with sweeping in micellar electrokinetic chromatography for the dual-stacking strategy of non-steroidal anti-inflammatory drugs in environmental water samples

Realising the need to devise a simple, sensitive, and reliable detection method, this study investigated the development of a dual-stacking transient isotachophoresis (t-ITP) and sweeping in micellar electrokinetic chromatography with diode array detector (t-ITP/sweeping-MEKC-DAD) for the determination of selected non-steroidal anti-inflammatory drugs (NSAIDs); ketoprofen, diclofenac and naproxen from aqueous matrices. Prior to the system setup, various parameters were optimised to assess the potential use of the t-ITP paired with the sweeping stacking technique in micellar background electrolyte for dual preconcentration and separation of trace amounts of NSAIDs. Once the optimum conditions have been established, the method performance was validated and applied to 17 environmental water samples. Based on the results, the combined t-ITP and sweeping approach significantly improved the stacking and separation sensitivity. A large volume of samples could also be introduced and subsequently separated by MEKC with greater focusing effects due to the sweeping. Under optimised conditions, the developed method exhibited excellent linearity at a high range (0.1–500 ng/mL, r2 ≥ 0.998), low limits of detection (LODs) of 0.01–0.07 ng/mL, and a remarkable relative recovery (RR) of 99.6–101.9% with a relative standard deviation (RSD) of 1.4–8.6% (n = 9). Ultimately, the sensitivity enhancement factors improved up to 666-fold using the optimised method. Therefore, the proposed method presents a simplified yet effective and suitable for the determination of NSAIDs from aqueous matrices

A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5-fluorouracil and its metabolite in human plasma

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1-1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11-0.14 ng/ml) and satisfactory analyte relative recovery (97.4-99.7%) with relative standard deviations of 4.6-9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies

A simple and efficient sequential electrokinetic and hydrodynamic injections in micellar electrokinetic chromatography method for quantification of anticancer drug 5-fluorouracil and its metabolite in human plasma

A simple and sensitive preconcentration strategy using sequential electrokinetic and hydrodynamic injection modes in micellar electrokinetic chromatography with diode array detection was developed and applied for the separation and determination of anticancer agent, 5-fluorouracil and its metabolite, 5-fluoro-2'-deoxyuridine, in human plasma. Sequential injection modes with increased analyte loading capacity using the anionic pseudo-stationary phase facilitated collection of the dispersed neutral and charged analytes into narrow zones and improved sensitivity. Several important parameters affecting sample enrichment performance were evaluated and optimized in this study. Under the optimized experimental conditions, 614- and 643-fold and 782- and 803-fold sensitivity improvement were obtained for 5-fluorouracil and its metabolite when compared with normal hydrodynamic and electrokinetic injection, respectively. The method has good linearity (1–1,000 ng/ml) with acceptable coefficient of determination (r2 > 0.993), low limits of detection (0.11–0.14 ng/ml) and satisfactory analyte relative recovery (97.4–99.7%) with relative standard deviations of 4.6–9.3% (n = 6). Validation results as well as the application to analysis of human plasma samples from cancer patients demonstrate the applicability of the proposed method to clinical studies

Analytical method development and validation of anticancer agent, 5-fluorouracil, and its metabolites in biological matrices: an updated review

5-fluorouracil (5-FU) refers to a fluorinated pyrimidine analogue that has been widely used as an anticancer agent for colon, head, and neck cancers. Detection of 5-FU and its metabolites; 5-fluorouridine and 5-fluoro-2-deoxyuridine in biological samples allows optimization of pharmacotherapy and encourages fundamental investigations of this medication. The development of accurate and reliable sample preparation, as well as analytical methods, is critical to isolate targeted analytes from complex matrices, apart from increasing detection sensitivity of analytes. With that, this paper presents a review of prior studies pertaining to chromatographic and electrophoretic methods that focused on the analysis of 5-FU and its metabolites in biological matrices such as plasma and urine. This paper concentrates on HPLC, GC and CE systems, which are the most commonly used strategies for analytical separation of 5-FU and its metabolites from samples. Detection of these antineoplastic agents at trace level demands highly sensitive and selective analytical methodologies. Application of these analytical techniques to biological matrices is reviewed with a focus on method development strategies, including types of mobile phases and background electrolytes employed in LC and CE systems