Rapid determination of NSAIDs by capillary and microchip electrophoresis with capacitively coupled contactless conductivity detection in wastewater

Recent developments in electromigration techniques related to pharmaceutical and biomedical analysis - A review

The analysis of pharmaceutical compounds is an important research topic as the use of different drugs affects people's daily life for the treatment of diseases. In addition to the widespread use of the internet, counterfeit drugs have appeared in the market. The development of modern analytical techniques, reliable, precise, sensitive, and rapid methods, has provided powerful means of analysis used in various fields such as drug production, quality control, determination of impurities and/or metabolites, biochemistry, pharmacokinetics, etc. Analytical techniques so far used in the pharmaceutical analysis include high-performance liquid chromatography (HPLC), gas chromatography (GC), super/sub-critical fluid chromatography (SFC), and capillary electromigration techniques such as capillary electrophoresis (CE) and rather rarely capillary electrochromatography (CEC). CE has some advantages over other techniques, e.g., very high efficiency, reduced costs (use of minute volumes of solvents and samples), the possibility to use different separation mechanisms, etc. In this review paper, the main features and limitations of the capillary electromigration techniques (especially CE) are discussed. Some selected applications of CE to the analysis of pharmaceutical compounds published in the period 2021-2023 (May) are reported.

A Novel Symmetrical Peak Fitting Method Based on Improved WOA Algorithm for the Analysis of Microchip Electrophoresis Signals

The problem of overlapping peaks has been a challenge in microchip electrophoresis (ME) signal analysis. However, traditional peak fitting algorithms have difficulty analyzing overlapping peaks due to the high dependence on the starting point. In this study, we propose a symmetrical peak fitting method named the tent-mapped whale optimization algorithm and Levenberg–Marquardt (TWOALM), which combines a whale optimization algorithm (WOA) improved by one of the most commonly used chaotic maps, the tent map and the Levenberg–Marquardt (LM) algorithm. Specifically, we first derive the fitted model for the overlapping peaks, showing that it is separable nonlinear least squares, significantly reducing the number of parameters to be optimized. Second, we integrate the tent map into the WOA, which improves the convergence speed of the peak fitting algorithm. Finally, we propose an efficient peak-fitting algorithm that combines the improved WOA and LM. The advantage of the proposed algorithm is that it is significantly faster than WOA and significantly more accurate than the LM algorithm. The results of fitting the synthetic peaks and ME signals showed that the combination of the chaotic map-based WOA algorithm and the LM algorithm can significantly improve the peak fitting performance and provide an effective solution for the analysis of overlapping peaks.

Novel microchip electrophoresis-contactless conductivity method for detection and characterization of extracellular vesicles enriched for exosomes and microvesicles

Background: Extracellular vesicles (EVs) are important carriers of intercellular communication, used in disease diagnosis and as prognostic circulating biomarkers, and their identification and quantitative analysis are important prerequisites for their clinical application. Methods & results: A method using microchip electrophoresis with contactless conductivity detection was developed for the concentration assay of EVs. This method showed good sensitivity, reproducibility and accuracy, with good linear correlation with conventional methods (nanoparticle tracking analysis and bicinchoninic acid assay). The application to the detection of mesenchymal stem cell-derived EVs proved its applicability to clinical samples. Conclusion: This is the first study to apply this method for the detection of EVs, achieving quantitative analysis of EVs enriched in exosomes and microvesicles, and initially demonstrating the potential to separate different EV subpopulations.