In this study, we developed a novel and environmentally friendly method for the determination of selected cannabinoids - cannabidiol, cannabinol, tetrahydrocannabinol, JWH 073 synthetic cannabinoid, hexahydrocannabinol (HHC), and hexahydrocannabinol-O-acetate - using high-performance liquid chromatography with electrochemical detection. The method employs a boron-doped diamond working electrode, which offers significant advantages in comparison with commonly used materials. Its main strengths include low background currents, reduced fouling, and an extended potential window, making it suitable for detecting compounds that are not readily oxidizable. The chromatographic system utilized a reversed-phase Gemini C18 column with a mobile phase consisting of acetonitrile and 25 mM phosphate buffer (pH 4.4) in step-gradient mode from 68 % to 88 % acetonitrile. The separation and determination of cannabinoids were optimized to be completed in less than 25 min. Hydrodynamic voltammetry was performed to identify the optimal potential for the amperometric detection, with a working potential of + 1400 mV (vs. Pd/H₂) providing the best analytical response based on S/N ratio. Under these optimal separation and detection conditions, the limits of detection were within the range of 6.1-666 nM (for cannabidiol and 9(R)-hexahydrocannabinol-O-acetate), while the response was linear within the concentration range measured up to 10 μM. The method demonstrated good linearity, precision, and sensitivity, with limits of detection and quantitation reaching nanomolar levels. The developed method was successfully applied to commercial samples of HHC jelly bears and HHC distillate.

In this work, we demonstrate a sensitive high-performance liquid chromatography (HPLC) method for the determination of piperazine antihistamine drugs employing innovative electrochemical detection based on a spark-generated nickel oxide nanoparticle-modified carbon fiber microelectrode built into a miniaturized electrochemical detector. The direct carbon fiber-to-nickel plate electrode spark discharge, carried at 0.8 kV DC, with the nickel electrode connected to the negative pole of the high-voltage power supply, provides extremely fast (1 s) in situ tailoring of the carbon fiber microelectrode surface by nickel oxide nanoparticles. It has been found that nickel oxide nanoparticles exhibit an electrocatalytic effect toward the piperazine moiety electrooxidation process, as confirmed by voltammetric experiments, revealing the shift in the peak potential from 1.25 to 1.09 V versus Ag/AgCl. Cetirizine, cyclizine, chlorcyclizine, flunarizine, meclizine, and buclizine were selected as sample piperazine antihistamine drugs, while diclofenac served as an internal standard. The isocratic reversed-phase separation of the above set was achieved within 15 min using an ARION-CN 3 mu m column with a binary mobile phase consisting of 50 mM phosphate buffer (pH 3) and methanol (45/55, v/v). The limits of detection (LOD) were within the range of 3.8-120 nM (for cyclizine and buclizine) at E = +1500 mV (vs Ag/AgCl), while the response was linear within the concentration range measured up to 5 mu mol L-1. The method was successfully applied to the determination of piperazine antihistamine drugs in spiked plasma samples.

This study presents the development and validation of a novel capillary zone electrophoresis method for the precise determination of glatiramer acetate and its amino acid constituents. A 120 mmol dm −3 phosphoric acid solution adjusted to pH 1.9 with Tris, supplemented with 20 mmol dm −3 triethylamine to achieve a final of pH 2.1, resulted in a repeatable analysis of glatiramer acetate. The method demonstrated a limit of detection and quantification of 39.2 µg cm −3 and 130.7 µg cm −3 , respectively. This method allows for the rapid control of glatiramer acetate-based pharmaceuticals and distinguishes glatiramer acetate from the amino acids used in its synthesis. Graphical abstract

A novel methodology for investigating the behavior of nanoparticles in their mixtures in aqueous high-ionic strength conditions is presented in this work. Our approach utilizes Taylor dispersion analysis in capillaries connected to inductively coupled plasma mass spectrometry (ICP-MS) to probe metal-derived nanoparticles. This methodology simultaneously distinguishes between different kinds of nanoparticles and accurately determines their essential parameters, such as hydrodynamic size, diffusion coefficient, and elemental composition. Moreover, the isotope-specific ICP-MS detection allows for unique targeting of the fate of isotopically enriched nanoparticles. The complexity of our methodology opens the way for studying barely explored areas of interparticle interactions or unequivocal characterization of one type of nanoparticle in complex mixtures without any need for calibration as well as labor-consuming sample preparation.

This research focuses on the development and validation of a capillary electrophoresis (CE) method for the chiral separation of three H1-antihistamine drugs chlorcyclizine, norchlorcyclizine, and neobenodine using sulfated β-cyclodextrin (S-β-CD) as the chiral selector. The study explores various factors influencing the separation efficiency, including CD concentration, organic modifier content, voltage application, and buffer pH. Optimal conditions were identified as a 100 mM phosphate buffer (pH 6.0) with 34 mg mL-1 S-β-CD and 40% (v/v) methanol. The method demonstrated excellent linearity in calibration curves, with coefficients of determination exceeding 0.99 for each enantiomer. Precision studies revealed good intra- and inter-day precision for migration times and peak areas. The limits of detection and quantification for the analytes were within the ranges of 5.9-11.4 and 18-34.6 µmol L-1, respectively. Overall, the developed CE method offers a robust and precise approach for the chiral separation of H1-antihistamine drugs, holding promise for pharmaceutical applications.

Metal–organic frameworks (MOFs), as high-surface-area materials, have shown promise in various areas of application, such as chiral sensing and separation, due to their flexibility in design and organized porous cages. Researchers have been striving to design and develop high-performance enantiorecognition and separation analytical techniques in chiral science fields. The main aim of this review is to provide a comprehensive overview of chirality, state-of-the-art MOFs in chirality, and chiral analysis in the past decade, 2012–2022. The classification of this review includes chirality, principles of chiral analysis, the attraction of functional materials in chirality, MOFs in chiral analysis, MOFs for designing enantioselective sensors (fluorescence, circular dichroism, quartz crystal microbalance, electrochemical), and MOFs as chiral stationary phases (CSPs) for chromatographic enantioseparation (high-performance liquid chromatography, gas chromatography, and capillary electrochromatography). Finally, this review covers the vital progress of these materials with attention to the available opportunities and challenges in this topic.

Dasatinib is an anticancer drug that treats acute lymphoblastic leukemia, chronic myelogenous leukemia, and prostate cancer with several side effects. In this research, we suggest nanoparticle-modified screen-printed electrodes (SPCEs) as disposable electrochemical sensors for fast quantification of dasatinib in pharmaceutical formulations. Carbon nanotubes, single-walled carbon nanotubes (SWCNT), graphene, and graphene oxide-modified SPCEs were characterized by scanning electron microscopy. The study also recommends SWCNT-modified SPCEs as the best-performing electrode for determining dasatinib, demonstrating an excellent boosting effect on the oxidation response of dasatinib. This was accomplished using the square-wave voltammetry method. After optimization of the pH condition, pH 5.0 Britton–Robinson buffer, SWCNT-modified SPCEs demonstrated 94% recovery with optimum electro-oxidation activity. The oxidation currents exhibited linear relation with dasatinib concentration in the 0.1–100 µM. Based on the results, a limit of detection of 0.06 µM was obtained in the standard solution. The SWCNT-modified SPCEs have been applied to analyze dasatinib in pharmaceutical tablet samples. The demonstrated performance beats all comparable standard analytical tools and presumably may be used for general drug quantitation in pharmaceutical tablets. Graphical abstract

The aim of our work was to develop a new method for the analysis of tamsulosin enantiomers by capillary electrophoresis connected with tandem mass spectrometry. The pharmacologically active (R)-enantiomer of tamsulosin, is used to treat benign prostatic hyperplasia and chronic prostatitis. Under the optimal conditions, background electrolyte consisting of 200 mM acetic acid titrated with NH4OH to pH 4.0 containing 4.0 mg mL-1 sulfated β-cyclodextrin, an injection time of 40 s at 50 mbar, a voltage of 20 kV and an optimized MS set-up (as e.g., sheath liquid containing 75 : 24.9 : 0.1 MeOH, H2O, and formic acid, v/v), a limit of detection of 1.6 nmol L-1 was achieved. The method was validated in terms of linearity, detection and quantification limits, precision, recovery, and selectivity. The results showed that the method can be used for the analysis of tamsulosin enantiomers in environmental samples, but generally, it can be applied to many different analytical tasks.

Capillary electrophoresis connected with tandem mass spectrometry was employed for the development of a method for determination of various tyrosine kinase inhibitors in plasma samples. A stacking online preconcentration with a 120 cm-long capillary was used for the determination of bosutinib, dasatinib, canertinib, and erlotinib at physiologically relevant concentrations. The optimization included both capillary electrophoresis and mass spectrometry steps. Under optimal conditions, 50 mM formic acid pH 2.5, an injection time of 120 s, and an optimized mass spectrometry set-up (as sheath liquid composition 75:24.9:0.1 (v/v) methanol, water, formic acid, and appropriate conditions for ion transitions), LODs in a range of 3.9–23.0 nmol·L−1 were observed. The method was validated in terms of linearity, limit of detection, limit of quantification, repeatability of migration times and peak area, and recovery using plasma as a matrix for analytes. The results showed that this method has great promise for use in many analytical tasks, e.g., therapeutic drug monitoring.

Oxaliplatin represents a platinum-based cancerostatic drug that is widely used for the treatment of various types of cancer. There are two main platinum-containing impurities, impurity B and C, that can be formed as side products at very low concentrations. Their effect on biological systems can be like the oxaliplatin itself; however, this has not been fully investigated since there is a lack of methods for their determination in ultralow con-centrations. In our work, we present a method for ultra-trace determination of oxaliplatin impurities B and C, and oxaliplatin itself, using online sweeping preconcentration micellar electrokinetic chromatography coupled with inductively coupled plasma mass spectrometry (MEKC-ICP-MS). This is the first application of online pre-concentration with MEKC-ICP-MS to improve the detection limits of analytes. Under the optimal conditions, 25 mM sodium phosphate buffer at pH 2.15 with 175 mM SDS, and an injection time of 90 s at 50 mbar, baseline separation of all components within 6 min was achieved. The sweeping-MEKC-ICP-MS method was fully vali-dated in terms of linearity, limits of detection and quantification, trueness, precision, and reproducibility of migration times. Limits of detection of 2, 1, and 3 ng mL(-1) for impurity B, impurity C, and oxaliplatin, respectively, were obtained, which are 3,500-, 1,700-, and 2,100-fold lower than those for a MEKC-UV method also developed and validated as a part of this work. It also represents the detection of 98 femtograms of the impurity C (or 227 attomol of Pt) per injection. The sweeping-MEKC-ICP-MS method further benefits from a wide dynamic range up to six orders of magnitude (0.01-1,000 mu g mL(-1) for oxaliplatin) with coefficients of deter-mination greater than 0.9989. ICP-MS provides characteristic element/isotope-specific and structure-independent detection. ICP-MS helped identify the co-separated impurity B counter-ion that can be wrongly assigned as the platinum-based impurity B using standard UV detection. Finally, the validated sweeping-MEKC-ICP-MS method was applied to the analysis of oxaliplatin samples with variable impurities concentrations (0.06-1.0%). The trueness and precision ranged between 76 and 115% and 2-19%, respectively. This method allows the accurate determination of oxaliplatin impurities from 0.0003% levels; therefore, it could be used in routine pharmaceutical laboratories for quality control purposes.

The aim of our work was to develop a low-cost, portable device for the fast and easy determination of total protein content by using PDMS-based lab-in-a-syringe technology with removal of 3D-printed channels. We proposed two designs with a one-step PDMS curing and a two-step PDMS-curing fabrication procedure. The one-step PDMS microdevices were found to be the best in the view of preparation, repeatability, and stability of the reagent. This design was then applied for the determination of total protein content in biomedical products using the Bradford assay.

In our work, we produced PDMS-based microfluidic devices by mechanical removal of 3D-printed scaffolds inserted in PDMS. Two setups leading to the fabrication of monolithic PDMS-based microdevices and bonded (or stamped) PDMS-based microdevices were designed. In the monolithic devices, the 3D-printed scaffolds were fully inserted in the PDMS and then carefully removed. The bonded devices were produced by forming imprints of the 3D-printed scaffolds in PDMS, followed by bonding the PDMS parts to glass slides. All these microfluidic devices were then successfully employed in three proof-of-concept applications: capture of magnetic microparticles, formation of droplets, and isotachophoresis separation of model organic dyes.

The aim of this study was to develop a fast method of screening for orotic acid in untreated urine by capillary electrophoresis with using a combination of two capillaries with different internal diameters, 50 μm and 100 μm. Under the optimized conditions, 100 mM sodium phosphate buffer pH 2.2, voltage of 5 kV, hydrodynamic injection at 50 mbar for 5 s, and detection at 214 nm, the migration time of orotic acid was only 2.1 min. The validation of the method resulted in orotic acid recoveries of 96.5 ± 0.8%. We achieved good precision with RSD of migration times at less than 0.8% and peak areas lower than 3.1% intraday precision. We obtained a very good linearity in the validated range 1–100 μmol L−1, R2 0.9993, and a limit of detection of 2.4 μmol L−1. Finally, we proved that the method is robust, including the connection of capillaries, using the Youden test.

Introduction Capillary electrophoresis (CE) hyphenated to inductively coupled plasma mass spectrometry (ICPMS) as an element-specific detector represents an interesting and beneficial tool for many applications. Nowadays, CE-ICP-MS is used primarily for speciation analysis, metal-ligand interaction studies including metal-based nanoparticles, as recently reviewed [1]. However, CE-ICP-MS has the potential to touch also other fields by taking account of other advantages of CE, e.g. in chiral separations or in online preconcentration methodologies.

We have developed a fast and efficient method for the determination of alloxan in flour samples by capillary electrophoresis with tandem mass spectrometry without derivatization step. Mass spectra of alloxan were studied in detail providing characteristic signals at m/z 159, 141 and 115. The separation lasted 8 min under the optimum conditions using 50 mM ammonium acetate pH 9.5 as the background electrolyte and uric acid as the internal standard. Five flour samples including bleached flour from the USA were analyzed and alloxan was not detected in any of these samples.

The aim of this study was to focus on the reduction of chiral selector concentration, sulfated-beta-cyclodextrin, in an attempt decrease the running costs associated with separating cetirizine enantiomers by capillary electrophoresis. The decrease in the concentration of chiral selector was achieved by adding D-glucose to the background electrolyte, which consisted of sodium borate. Optimal separation of cetirizine enantiomers was obtained in the electrolyte containing 500 mmol L-1 borate pH 9.5 with 1.0 mg mL(-1) sulfated-beta-cyclodextrin, and 1000 mmol L-1 D-glucose. This means a 15-fold reduction in the concentration of sulfated-beta-cyclodextrin. The mechanism of the separation in this electrolyte was investigated using direct injection mass spectrometry. The electrolyte of borate, D-glucose, and sulfated-beta-cyclodextrin forms a dual selector system, in which one selector is represented by the sulfated-beta-cyclodextrin and the second selector is represented by the D-glucose-borate complexes.

In this work, interactions of carboxylated core shell magnetic nanoparticles with polymyxin B sulfate were studied by connecting capillary electrophoresis with inductively coupled plasma mass spectrometry. The interaction was probed by affinity mode of capillary electrophoresis with 25 mM phosphate buffer at physiological pH. 54Fe, 56Fe, 57Fe, 34S, and 12C isotopes were used to monitor the migration of an electroosmotic flow marker and the interaction of the nanoparticles with polymyxin B. The analysis of interaction data showed two distinct interaction regions, one with low polymyxin B concentration, the second with high polymyxin B concentration. These regions differed in the strength of the interaction, 1.49 × 107 M-1 and 1.60 × 104 M-1, and in the stoichiometry of 0.7 and 3.5, respectively. These differences can be explained by the decrease of electrostatic repulsion between nanoparticles caused by polymyxin B. This is also in agreement with the nanoparticles peak shapes: sharp for low polymyxin B concentrations and broad for high polymyxin B concentrations.

The aim of this study was to develop a method for the separation of oxaliplatin enantiomers at attomolar concentration levels. A combination of capillary electrophoresis and inductively coupled plasma mass spectrometry was chosen due to their unique characteristics, including fast and easy modification of separation selectivity, and significant limits of detection and linearity. In the first step, we optimized conditions for the separation of oxaliplatin enantiomers including background electrolyte composition and concentration, pH, and type and concentration of the chiral selector. Under optimal conditions, sodium borate buffer pH 9.5, ionic strength 40 mmol L-1, with 60 mg mL(-1) sulfated beta-cyclodextrin, separation was obtained with a resolution of 2.0. This electrolyte system was then used in the 'in-house' connection of capillary electrophoresis with inductively coupled plasma mass spectrometer. In this instance, separation lasted for 9.5 min. Calibrations were linear in the range of 0.1-500 mu g mL(-1) with R-2 of 0.9999. LOD and LOQ values were of 64 ng mL(-1 )and 116 ng mL(-1) of oxaliplatin, respectively. This represents detection of 49 fg or 125 attomol of oxaliplatin enantiomers in the capillary electrophoresis injected sample zone. Finally, the method was successfully applied for detection of oxaliplatin enantiomers in spiked urine samples.