Search Results (40)

This study aimed to develop a reliable method for profiling reducing sugars in honey using capillary zone electrophoresis with laser-induced fluorescence detection (CZE-LIF). Reducing sugars were derivatized with 8-aminopyrene-1,3,6-trisulfonic acid (APTS) in the presence of 2-picoline borane, a safer alternative to sodium cyanoborohydride. Key parameters influencing the derivatization efficiency—temperature, pH, incubation time, and reagent concentrations—were systematically optimized. The highest labeling efficiency for glucose, mannose, and maltose was achieved at 50 °C in 0.5 M citric acid with 0.1 M APTS, while fructose showed low reactivity due to its ketose structure. To reduce the background signal from excess reagents, three cleanup strategies were evaluated. Liquid–liquid extraction with ethyl acetate effectively removed unreacted APTS without significant analyte loss, whereas solid-phase extraction and microextraction caused substantial losses of hydrophilic sugars. The method showed good linearity (0.5–10 mM, R² > 0.994), precision (RSD 0.81–13.73%), and accuracy (recoveries 93.47–119.75%). Stability studies indicated that sugar standards should be stored at –20 °C. The method was successfully applied to the analysis of four nectar honeys—rapeseed, acacia, phacelia, and dandelion—revealing differences in glucose and fructose content related to botanical origin. The results confirm the suitability of CZE-LIF for sensitive and selective carbohydrate analyses in complex food matrices. Full article

Nimesulide is a popular non-steroidal anti-inflammatory drug (NSAID) and a cyclooxygenase-2 inhibitor available in more than 50 countries worldwide. A rapid and simple method for nimesulide determination is presented. Experimental parameters based on a previously published work were revised and adopted into a method with significantly better performance: pH was shifted from 8.10 to 9.25, borate background electrolyte concentration from 10 to 60 mM—resulting in a run time less than 4 min, and number of theoretical plates greater than 100,000. The method was validated and applied for the determination of nimesulide in three formulations with the active substance of nimesulide: tablets, gel, and powder (in sachets for oral suspension). Also, the tablets were tested for uniformity of content of single-dose preparations according to Ph. Eur. Full article

Background: The enzymatic activity of acetylcholinesterase (AChE) has been a focal point in neurodegenerative diseases research, particularly in relation to Alzheimer’s disease. This is attributed to the significantly reduced levels of cholinergic neurons observed in Alzheimer’s patients compared to healthy individuals. The strategy to mitigate the onset of these diseases in patients lies in the exploration of new potential AChE inhibitors with a focus also on natural extracts. A rapid and specific capillary electrophoresis method with direct ultraviolet detection (CZE-UV/Vis) was developed to screen natural extracts by assessing their potential to inhibit AChE. Materials and Methods: To enhance the specificity when analysing complex matrixes such as natural extracts, a sequential analysis approach based on the “sandwich model” was implemented using Ellman’s reagent [5,5′-dithiobis-(2-nitrobenzoic acid)] (DTNB) as a colorimetric indicator. Results: A reference inhibitor, neostigmine, was used for system validation through IC₅₀ and K_i values determination by subsequent injections of acetylthiocholine substrate in the presence of neostigmine at increasing concentrations, and the enzyme combined with DTNB in borate-phosphate buffer (30 mM, pH 8.0). The enzymatic product was selectively detected at 412 nm. The validated system was applied to the analysis of seven natural extracts. Conclusions: Results demonstrated promising outcomes for identifying phytotherapeutic agents with potential applications in the prevention of neurodegenerative diseases. This method provides high selectivity and automation, offering a streamlined and effective approach for screening natural matrices containing potential AChE inhibitors. Full article

Cyanobacteria are an ancient group of prokaryotes capable of oxygenic photosynthesis. Recently, thermal crises symptoms in hot springs have been associated with acute cyanopeptides poisoning. The aim of this work is to develop a fast, easy and reliable method to monitor the presence of toxic cyanopeptides in geothermal waters. The analytical method based on capillary zone electrophoresis coupled with tandem mass spectrometry (CZE-MS/MS) was developed for the simultaneous determination of 14 cyanopeptides in less than 7.5 min. A basic 50 mM ammonium acetate buffer at pH 10.2 was selected as the background electrolyte, positive electrospray ionization (ESI+) was employed for all compounds, and a salting-out assisted liquid–liquid extraction (SALLE) protocol with acetonitrile as an extraction solvent and MgSO₄ as an auxiliary salting-out agent was optimized as sample treatment. Six natural hot springs in the province of Granada (Andalucía, Spain) were sampled at the beginning of the summer season (June) and at the end (September). Biomass collected at two sample points (Santa Fe and Zújar) contained cyanobacteria cells from the genera Phormidium, Leptolyngbya, and Spirulina. Nevertheless, cyanotoxins covered by this work were not found in any of the water samples analyzed. The greenness and transferability of the method was evaluated highlighting its sustainability and applicability. Full article

The diagnostic utility and reference intervals for blood studies in Aldabra giant tortoises (Aldabrachelys gigantea) are not well described. Capillary zone electrophoresis (CZE) has been evaluated in non-mammalian vertebrates and shows a higher fraction resolution and less overall variation in results than agarose gel electrophoresis. To date, the investigation of novel biomarkers has been limited in reptiles. MRP-126, a calgranulin homologue in reptiles, has not been evaluated for its diagnostic potential in tortoises. The goals of this study were to establish preliminary reference intervals for CZE protein electrophoresis and to examine MRP-126 as a potential biomarker of inflammation in Aldabra giant tortoises. In 27 clinically healthy tortoises, CZE resolved seven protein fractions. In tortoises with an inflammatory or infectious disease process (n = 4), MRP-126 concentrations and CZE fractions did not consistently increase or were abnormal. To strengthen the understanding of the diagnostic value of CZE and MRP-126 concentration in this species, future studies should evaluate a larger sample set inclusive of repeated measures of clinically abnormal tortoises as well as CZE and MRP-126 variations in regard to additional health conditions, age, sex, season, and geographic location. Full article

The present work describes, for the first time, an eco-friendly capillary zone electrophoresis (CZE) methodology for determining apixaban (APX), an oral anticoagulant. Separation was carried out using a fused silica capillary with an applied voltage of 20 kV and hydrodynamic injection for 5 s at 50 mbar. The electrolyte system consisted of 50 mM sodium borate at pH 8.0. The method was validated as recommended by ICH, establishing selectivity, linearity, precision, accuracy, and robustness. The analytical procedure was linear in the range of 10–125 µg mL⁻¹ (r = 0.999). The limits of detection and quantification were determined to be 1.77 µg mL⁻¹ and 5.37 µg mL⁻¹, respectively. Precision was evaluated by relative standard deviation (RSD), with an intra-day RSD (n = 6) of 0.96% and an inter-day RSD (n = 18) of 4.42%. The average recovery rates for the pharmaceutical samples were excellent, ranging from 98.03% to 101.01%, with an RSD of 1.51%. Moreover, the green profile of the method was evaluated using the National Environmental Methods Index (NEMI), Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), and Analytical GREEnness Metric (AGREE) assessment tools. The results suggest that the CZE method aligns with the principles of green chemistry, offering a greener alternative for the routine analysis of APX quality control. Also, the method presents a low-cost analysis, using fewer organic solvents and minimizing waste generation compared to techniques commonly used in routine analysis. Full article

Capillary zone electrophoresis–immunosubtraction (CZE-IS) is an essential laboratory test in diagnosing plasma cell neoplasms. However, the current interpretation of the test results is subjective. To evaluate CZE-IS in a more precise manner, this study proposed five key indexes, namely sharpness index, light chain index, immunoglobulin G index, immunoglobulin A index, and immunoglobulin M index. The reference intervals of these indexes were established using CZE-IS curve data from a clinical laboratory of a referral medical center. A total of 1000 cases with normal electrophoretic patterns were sampled for reference intervals establishment, and an additional 20 cases were included for validation. The following reference intervals in the γ zone were established: 1-6 (sharpness index), 1.06-2.71 (light chain index), 37-454 (immunoglobulin G index), (−9)-41 (immunoglobulin A index), and (−16)-46 (immunoglobulin M index). For the β2 zone, the reference intervals were 3-17 (sharpness index), 0.44-1.90 (light chain index), (−7)-61 (immunoglobulin G index), 2-117 (immunoglobulin A index), and (−12)-35 (immunoglobulin M index). The diagnostic performance of reference intervals of the proposed indexes in validation ranged from 95% to 100%. CZE-IS indexes provide the objective quantification of key characteristics of CZE-IS curves and improve the precision of CZE-IS interpretation. Full article

Monitoring and measuring pharmaceutical pollutants in environmental samples is a vital and complex task due to their potential detrimental effects on human health, even at low levels. Using capillary zone electrophoresis (CZE) and ultra-high-performance liquid chromatography (UHPLC), it was possible to separate and measure three commonly used antipsychotic drugs, chlorpromazine (CPZ), haloperidol (HAL), and risperidone (RIS), in wastewater of the pharmaceutical industry. The technique of solid-phase extraction (SPE) was developed and implemented as a very effective method for preparing samples prior to analysis. The settings of the capillary electrophoretic and chromatographic techniques were adjusted to obtain the most efficient separation profile for the medications being studied. The concentration of all the medicines being investigated ranged from 0.5 to 50 µg/mL. SPE was used to treat real wastewater samples after a thorough validation process that followed the rules set by ICH-Q2B. The developed assays were then effectively employed to identify the tested antipsychotic substances in the real wastewater samples. The provided methodologies may be efficiently utilized to monitor the extent of environmental contamination caused by the investigated pharmaceuticals. Full article

Nowadays, lipidomics plays a crucial role in the investigation of novel biomarkers of various diseases. Its implementation into the field of clinical analysis led to the identification of specific lipids and/or significant changes in their plasma levels in patients suffering from cancer, Alzheimer’s disease, sepsis, and many other diseases and pathological conditions. Profiling of lipids and determination of their plasma concentrations could also be helpful in the case of drug therapy management, especially in combination with therapeutic drug monitoring (TDM). Here, for the first time, a combined approach based on the TDM of colistin, a last-resort antibiotic, and lipidomic profiling is presented in a case study of a critically ill male patient suffering from Pseudomonas aeruginosa-induced pneumonia. Implementation of innovative analytical approaches for TDM (online combination of capillary electrophoresis with tandem mass spectrometry, CZE-MS/MS) and lipidomics (liquid chromatography–tandem mass spectrometry, LC-MS/MS) was demonstrated. The CZE-MS/MS strategy confirmed the chosen colistin drug dosing regimen, leading to stable colistin concentrations in plasma samples. The determined colistin concentrations in plasma samples reached the required minimal inhibitory concentration of 1 μg/mL. The complex lipidomics approach led to monitoring 545 lipids in collected patient plasma samples during and after the therapy. Some changes in specific individual lipids were in good agreement with previous lipidomics studies dealing with sepsis. The presented case study represents a good starting point for identifying particular individual lipids that could correlate with antimicrobial and inflammation therapeutic management. Full article

Monitoring plasma concentrations of β-lactam antibiotics is crucial, particularly in critically ill patients, where variations in concentrations can lead to treatment failure or adverse events. Standardized antimicrobial regimens may not be effective for all patients, especially in special groups with altered physiological parameters. Pharmacokinetic/pharmacodynamic (PK/PD) studies highlight the time-dependent antibacterial activity of these antibiotics, emphasizing the need for personalized dosing. Therapeutic drug monitoring (TDM) is essential, requiring rapid and accurate analytical methods for precise determination of drugs in biological material (typically plasma or serum). This study presents a novel capillary zone electrophoresis–tandem mass spectrometry (CZE-MS/MS) method designed for the simultaneous quantification of five penicillin antibiotics, two cephalosporins, one carbapenem, and two β-lactamase inhibitors in a single run. The method involves a simple sample pretreatment—precipitation with organic solvent—and has a run time of 20 min. Optimization of CZE separation conditions revealed that 20 mM ammonium hydrogen carbonate (NH₄HCO₃) serves as the optimal background electrolyte (BGE). Positive electrospray ionization (ESI) mode, with isopropyl alcohol (IP)/10 mM ammonium formate water solution (50/50, v/v) as the sheath liquid, was identified as the optimal condition for MS detection. Method validation according to the Food and Drug Administration (FDA) guideline for development of bioanalytical methods demonstrated satisfactory selectivity, linearity, recovery, robustness, and stability. The method’s practicality was evaluated using the Blue Applicability Grade Index (BAGI), yielding a score of 77.5. Moreover, the greenness of the proposed method was evaluated by two commonly used metric tools—Analytical GREEnness (AGREE) and Green Analytical Procedure Index (GAPI). The developed CZE-MS/MS method offers a practical and reliable approach for quantifying a broad spectrum of β-lactam antibiotics in plasma. Its ability to simultaneously quantify multiple analytes in a single run, coupled with a straightforward sample pretreatment, positions it as a valuable and prospective tool for TDM in critically ill patients. Full article

Compacted graphite iron (CGI) is an engineering material with the potential to fill the application gap between flake- and spheroidal-graphite irons thanks to its unique microstructure and competitive price. Despite its wide use and considerable past research, its complex microstructure often leads researchers to focus on models based on representative volume elements with multiple particles, frequently overlooking the impact of individual particle shapes and interactions between the neighbouring particles on crack initiation and propagation. This study focuses on the effects of graphite morphology and spacing between inclusions on the mechanical and fracture behaviours of CGI at the microscale. In this work, 2D cohesive-zone-element-based models with different graphite morphologies and spacings were developed to investigate the mechanical behaviour as well as crack initiation and propagation. ImageJ and scanning electron microscopy were used to characterise and analyse the microstructure of CGI. In simulations, both graphite particles and metallic matrix were assumed isotropic and ductile. Cohesive zone elements (CZEs) were employed in the whole domain studied. It was found that graphite morphology had a negligible effect on interface debonding but nodular inclusions can notably enhance the stiffness of the material and effectively impede the propagation of cracks within the matrix. Besides, a small distance between graphite particles accelerates the crack growth. These results can be used to design and manufacture better metal-matrix composites. Full article

We propose a platform called “LCA-Multidimensional Map (LAMP)” to support companies and individuals aiming for CO₂ zero emissions (CZEs) by efficiently conducting life cycle assessments (LCAs) of their products and activities, collecting information necessary for CZEs, and developing CO₂ reduction plans. LAMP is a multidimensional platform that supports the development of CZEs targets in cyberspace without temporal or spatial constraints. Using this software, LCAs can be conducted using existing database groups constructed in two and three dimensions in various sectors as well as data groups with temporal information, such as evolving and continuous records, and spatial information in a cross-sectional manner. Furthermore, based on the LCA results, CO₂-emission-reduction plans can be formulated (extraction of alternatives), and their effectiveness can be confirmed through LCA again. As an example of how to use LAMP, we introduce the characteristics of LCA in horticulture, the second-largest source of CO₂ emissions after livestock in the agricultural sector, along with examples of alternative plans for greenhouses, collaboration plans with other sectors, and basic methods for promoting CZEs in horticulture. Although this concept needs to be tested and validated in the future, it might encourage individuals or companies to cooperate in LAMP development or inspire them to advocate for more progressive ideas. Full article

Active pharmaceutical ingredients (APIs) can be assured to be safe and effective with the help of stability-indicating procedures. An accurate comparison comprising the utilization of capillary zone electrophoresis (CZE) and ultra-performance liquid chromatography (UPLC) for the sensitive and accurate measurement of ciprofloxacin (CPF) in the presence of its major photo-degradation product was conducted. The CZE and UPLC working conditions were optimized to obtain the best pattern of separation for CPF and its photo-degradant. The linearity range of the cited techniques was confirmed to be 0.5 to 50 µg/mL. A thorough validation scheme according to the ICH-Q2B criteria was performed, including linearity, accuracy, precision, robustness, detection, and quantification limits. Selective quantification of CPF in the presence of up to 90% of its main photo-degradant was carried out using the proposed methods. For the analysis of CPF in tablet and intravenous (I.V.) solution forms, the CZE and UPLC procedures were applied. The suggested methods can be applied to keep an eye on the safety and efficacy of CPF in either bulk or dosage forms. Full article

Capillary zone electrophoresis (CZE) is an important technique for the analysis of monoclonal antibodies (mAbs). A recently released light-emitting diode (LED)-induced fluorescence (LEDIF) detector equipped with a 275 nm LED for the detection of proteins through their native fluorescence was used in this study and compared to results obtained using the predominant detection mode, the measurement of the absorption of ultraviolet light (UV detection). This was accomplished using an established CZE method for the analysis of three mAbs: NISTmAb, matuzumab, and Intact Mass Check Standard (Waters). For this purpose, the detector’s settings were first optimized using a design of experiments approach. Three factors, rise time, photomultiplier high voltage supply, and acquisition frequency, were optimized by means of a D-optimal design. The optimal settings were then used for the investigation of signal-to-noise ratios (S/Ns), linearity, and precision. LEDIF detection offered a similar separation quality, up to 12 times higher S/Ns, and lower limits of detection compared to UV detection. Repeatability was excellent, with relative standard deviations (RSDs) of approximately 1% for percentage areas. For intermediate precision, RSDs of <2% (n = 3 × 10) were typically achieved. Overall, LEDIF detection was found to be an excellent and easily optimizable alternative to UV detection. Full article

Since active pharmaceutical ingredients (APIs) are directly related to human health, monitoring and quantifying them in the environment is a crucial and challenging issue. Using capillary-zone electrophoresis (CZE), four frequently used fluoroquinolones (FQs), ciprofloxacin, sparfloxacin, moxifloxacin, and gatifloxacin, were efficiently isolated and measured in pharmaceutical industrial wastewater. Solid-phase extraction (SPE) was developed and used as an efficient sample pretreatment procedure. The capillary electrophoretic procedure’s various parameters were tuned to produce the optimal separation pattern for the drugs under consideration. All of the drugs under study were quantified in a concentration range of 0.5 to 50 µg/mL. After full assay validation in compliance with ICH-Q2B criteria, real wastewater samples were subjected to effective SPE, and the proposed assay was successfully used to determine the examined FQs in real wastewater samples. Full article