Capillary Electrophoresis Method Research Articles

Simultaneous sequencing of 102 Y-STRs on Ion Torrent ™ GeneStudio ™ S5 System

The Precision ID NGS System from Thermo Fisher Scientific is a mainstream next-generation sequencing (NGS) platform used in forensic laboratories to detect almost all commonly used forensic markers, except for Y-chromosomal short tandem repeats (Y-STRs). This study aimed to: 1) develop a Y-STR panel compatible with the automatic workflow of the NGS system using Ion AmpliSeq Technology, 2) evaluate the panel performance following the SWGDAM guidelines, and 3) explore the possibility of using a combination workflow to detect autosomal STRs and Y-STRs (AY-STR NGS workflow). The GrandFiler Y-STR Panel was successfully designed using the ‘separating’ and ‘merging’ strategies, including 102 Y-STRs and Amelogenin with an average amplicon length of 133 bp. It is a mega Y-STR multiplex system in which up to 16 samples can be sequenced simultaneously on an Ion 530 ™ Chip. Developmental validation studies of the performance of the NGS platform, species specificity, reproducibility, concordance, sensitivity, degraded samples, case-type samples, and mixtures were conducted to unequivocally determine whether the GrandFiler Y-STR Panel is suitable for real scenarios. The newly developed Y-STR panel showed compelling run metrics and NGS performance, including 92.47% bases with ≥ Q20, 91.80% effective reads, 2106 × depth of coverage (DoC), and 97.09% inter-locus balance. Additionally, it showed high specificity for human males and 99.40% methodological and bioinformatical concordance, generated complete profiles at ≥ 0.1 ng input DNA, and recovered more genetic information from severely degraded and diverse case samples. Although the outcome when used on mixtures was not as expected, more genetic information was obtained compared to that from capillary electrophoresis (CE) methods. The AY-STR NGS workflow was established by combining the GrandFiler Y-STR Panel with the Precision ID GlobalFiler ™ NGS STR Panel v2 at a 2:1 concentration ratio. The combination workflow on NGS performance, reproducibility, concordance, and sensitivity was as stable as the single Y-STR NGS workflow, providing more options for forensic scientists when dealing with different case scenarios. Overall, the GrandFiler Y-STR Panel was confirmed as the first to effectively detect a large number of Y-STR markers on the Precision ID NGS System, which is compatible with 51 Y-STRs in commercial CE kits and 51 Y-STRs in commercial NGS kits and the STRBase. The panel is as robust, reliable, and sensitive as current CE/NGS kits, and is suitable for solving real cases, especially for severely degraded samples (degradation index > 10).

Complex formation with modified cyclodextrins for improving biopharmaceutical properties of baricitinib, a novel immunomodulatory drug

Baricitinib is an orally active drug that has recently been approved by FDA and EMA for the treatment of rheumatoid arthritis, alopecia areata, COVID-19 and other inflammatory diseases. The application of baricitinib is limited by its poor aqueous solubility. In this context, this work aims to improve the pharmacologically important properties of baricitinib through inclusion complex formation with modified cyclodextrins. For the first time, the complexation of baricitinib with modified cyclodextrins in aqueous solutions was studied using 1H NMR, capillary electrophoresis, and isothermal saturation method. Thermodynamic parameters of the complexation of the modified cyclodextrins with different ionized forms of baricitinib were obtained and analyzed. The impact of the nature of cyclodextrin substituents and the degree of ionization of baricitinib on the inclusion complex formation and solubilization is considered. The increase in baricitinib solubility in the presence of the modified cyclodextrins is accompanied by a decrease in the membrane permeability of the drug. It was shown that concentration dependences of the permeability coefficient can be used to predict the binding constants of baricitinib with cyclodextrins and the solubility-permeability interplay.

Comparison of the ForenSeq Signature Prep and ForenSeq MainstAY kits to traditional capillary electrophoresis kits for STR profile analysis from various DNA sources

ABSTRACT Comparisons of DNA profiles recovered from the crime-scene and a person through short tandem repeat (STR) analysis using capillary electrophoresis (CE) is the gold standard method of determining a match. A comparison of STR profiles generated using CE to massively parallel sequencing (MPS) methods was undertaken. The results showed CE methods recovered high percentages of autosomal or Y-STR markers individually, however, MPS produced more information at low inputs and a higher number of STR markers overall, showing the potential of MPS to provide additional data to assist in solving major crimes.

Influence of oligonucleotides structures for separation of diastereomers by capillary electrophoresis method using polyvinylpyrrolidone 1,300,000

In the field of oligonucleotides drug discovery, phosphorothioate (PS) modification has been recognized as an effective tool to overcome the nuclease digestion, and generates 2n of possible diastereomers, where n equals the number of PS linkages. However, it is also well known that differences in drug efficacy and toxicity are caused by differences in stereochemistry of oligonucleotides. Therefore, the development of a high-resolution analytical method that enables stereo discrimination of oligonucleotides is desired. Under this circumstance, capillary electrophoresis (CE) using polyvinylpyrrolidone (PVP) is considered as one of the useful tools for the separation analysis of diastereomers.In this study, we evaluated the several oligonucleotides with the structural diversities in order to understand the separation mechanism of the diastereomers by CE. Especially, five kinds of 2′-moieties were deeply examined by CE with PVP 1,300,000 polymer solution. We found that different trend of the peak shapes and the peak resolution were observed among these oligonucleotides. For example, the better peak resolution was observed in 6 mer PS3-DNA compared to the rigid structure of 6 mer PS3-LNA. As for this reason, the computational simulation revealed that difference of accessible surface area caused by the steric structure of thiophosphate in each oligonucleotide is one of the key attributes to explain the separation of the diastereomers. In addition, we achieved the separation of sixteen peak tops of the diastereomers in 6 mer PS4-DNA, and the complete separation of fifteen diastereomers in 6 mer PS4-RNA. These knowledge for the separation of the diastereomers by CE will be expected to the quality control of the oligonucleotide drugs.

Development of a capillary zone electrophoresis method to monitor magnesium ion consumption during in vitro transcription for mRNA production.

Messenger RNA (mRNA) vaccines represent a landmark in vaccinology, especially with their success in COVID-19 vaccines, which have shown great promise for future vaccine development and disease prevention. As a platform technology, synthetic mRNA can be produced with high fidelity using in vitro transcription (IVT). Magnesium plays a vital role in the IVT process, facilitating the phosphodiester bond formation between adjacent nucleotides and ensuring accurate transcription to produce high-quality mRNA. The development of the IVT process has prompted key inquiries about in-process characterization of magnesium ion (Mg++) consumption, relating to the RNA polymerase (RNAP) activation, fed-batch mode production yield, and mRNA quality. Hence, it becomes crucial to monitor the free Mg++ concentration throughout the IVT process. However, no free Mg++ analysis method has been reported for complex IVT reactions. Here we report a robust capillary zone electrophoresis (CZE) method with indirect UV detection. The assay allows accurate quantitation of free Mg++ for the complex IVT reaction where it is essential to preserve IVT samples in their native-like state during analysis to avoid dissociation of bound Mg complexes. By applying this CZE method, the relationships between free Mg++ concentration, the mRNA yield, and dsRNA impurity level were investigated. Such mechanistic understanding facilitates informed decisions regarding the quantity and timing of feeding starting materials to increase the yield. Furthermore, this approach can serve as a platform method for analyzing the free Mg++ in complex sample matrices where preserving the native-like state of Mg++ binding is key for accurate quantitation.

Annual review of capillary electrophoresis technology in 2023

This paper serves as an annual review of capillary electrophoresis (CE) technology for 2023. The journals were selected based on their impact factor (IF), a universally recognized academic performance metric, combined with experimental work closely related to CE technology, to facilitate the rapid acquisition of significant research and application advancements in CE technology in 2023. A thematic search of the ISI Web of Science database yielded 669 research papers on CE technology published in 2023. This review highlights five experimental papers published in journals with IFs greater than 10.0, including Nature Communications, Nucleic Acids Research, Engineering, Journal of Medical Virology, and Carbohydrate Polymers, and 31 experimental papers from representative journals with IFs between 5.0 and 10.0, such as Analytical Chemistry, Analytica Chimica Acta, Talanta, and Food Chemistry. It also provides an overview of experimental research in journals with focused reporting on CE technology but with IFs less than 5.0, such as Journal of Chromatography A and Electrophoresis, as well as significant experimental research from key domestic Chinese core journals (Peking University). In 2023, all the latest scientific advancements reported in journals with an IF greater than 10.0 utilized previously reported CE methods, offering new breakthroughs for the promotion and application of CE technology. Additionally, new applications of CE in conjunction with mass spectrometry remained a hot topic. An increase in reports on the hardware aspects of CE, such as 3D printing and underwater systems, and significant breakthroughs in the analysis of non-solution samples, such as solid particles, cell vesicles, cells, viruses, and bacteria, was noted. CE is advantageous for the analysis of drugs and their components. In Chinese journals, the number of papers on CE applications exceeded that in previous years, with particular focus on the field of printing for new applications.

Studying the acids and amino acid composition of horse chestnut flowers

Introduction. Currently, there is an increasing trend towards assessing the full spectrum of chemical compounds in plant materials. One of the first steps in the formation of secondary metabolites of complex structure, participating in biochemical processes in the plant body, which have their own effect on the human and animal body, are organic acids (OA) and amino acids (AA). However, due attention is not always given to these compounds when studying the component composition of plant raw materials.Aim. The purpose of the work was to study the profile and quantitative assessment of the content of organic acids and amino acids of Aesculus hippocastanum L. flowers.Materials and methods. The object of the study were horse chestnut flowers, collected during flowering in the Voronezh region in 2021 and dried by air-shade method. Quantitative assessment of the amount of TC in terms of malic acid and ascorbic acid was carried out titrimetrically according to the methods presented in the State Pharmacopoeia of the Russian Federation, XIV edition. The composition of the OA and AA profiles of horse chestnut flowers was determined using the capillary electrophoresis method ("Kapel®-105/105M", Group of Companies "Lumex", Russia).Results and discussion. The method of capillary electrophoresis revealed the presence of 12 compounds of the OA group in a total amount of 4.7 % (in terms of absolutely dry raw materials). The rationality of recalculating the content of the sum of OA to the major component – citric acid, which amounted to 1.65 ± 0.04 %, was shown. The content of ascorbic acid was low (0.033 ± 0.007) %. Using the TLC method, the presence of 5 zones of compounds belonging to the AA class was established in the aqueous extract of horse chestnut flowers. The quantitative content of the sum of free AA in terms of glutamine, determined by the spectrophotometric method, was 2.25 ± 0.07 % (n = 5). The presence of 17 AA was determined by capillary electrophoresis, which amounted to 7.13 %. Glutamic acid is present in the greatest quantity in horse chestnut flowers (1.19 %). Essential amino acids amounted to 2.27 %; leucine was present in the predominant amount (0.58 %).Conclusion. A study was carried out of the qualitative composition and quantitative content of organic acids and amino acids of horse chestnut flowers. The composition of the profile and the quantitative content of organic acids and amino acids have been established. It was revealed that citric acid prevails in the total organic acids; glutamic, aspartic acid, arginine and proline are found in greater quantities in the total amino acids.

Capillary zone electrophoresis method for quantification of therapeutic peptide glatiramer acetate

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

Magnetic solid-phase extraction based on restricted-access molecularly imprinted polymers for ultrarapid determination of ractopamine residues from food samples by capillary electrophoresis

An ultrafast, efficient, and eco-friendly method combining magnetic solid phase extraction and capillary electrophoresis with diode array detection have been developed to determine ractopamine residues in food samples. A restricted access material based on magnetic and mesoporous molecularly imprinted polymer has been properly synthesized and characterized, demonstrating excellent selectivity and high adsorbent capacity. Short-end injection capillary electrophoresis method was optimized: 75 mM triethylamine pH 7 as BGE, -20 kV, 50 mbar by hydrodynamic injection during 8 s, and capillary temperature at 25 °C; reaching ultrafast ractopamine analysis (∼0.6 min) with good peak asymmetry, and free from interfering and/or baseline noise. After sample preparation optimization, the conditions were: 1000 µL of sample at pH 6, 20 mg of adsorbent, stirring time of 120 s, 250 µL of ultrapure water as washing solvent, 1000 µL of methanol: acetic acid (7: 3, v/v) as eluent, and the adsorbent can be reused four times. In these conditions, the analytical method showed recoveries around to 100 %, linearity ranged from 9.74 to 974.0 µg kg−1, correlation coefficient (r) ≥ 0,99 in addition to adequate precision, accuracy, and robustness. After proper validation, the method was successfully applied in the analysis ractopamine residues in bovine milk and bovine and porcine muscle.

Simultaneous identification and enantioseparation of ofloxacin and duloxetine without the single standard and computational calculation of their inclusion complexes.

Given the markedly different pharmacological activities between enantiomeric isomers, it is crucial to encourage the stereoselective determination of chiral drugs in the biological and pharmaceutical fields, and the combination of drugs makes this analysis more complicated and challenging. Herein, a capillary electrophoresis (CE) method for the enantioseparation of ofloxacin and duloxetine was established, enabling the simultaneous identification of four isomers in nonracemic mixtures with enantiomeric excess (ee%) values exceeding 5%. This was achieved through the integration of theoretical simulation and electron circular dichroism (ECD), all without reliance on individual standards. Molecular modeling explained and verified the migration time differences of these isomers in electrophoretic separation. Moreover, the correlation coefficients (R2 ) between the enantiomeric peak area differentials and ee% were both above 0.99. Recovery rates were quantified using bovine serum as the matrix, with results ranging from 93.32% to 101.03% (RSD = 0.030) and 92.69% to 100.52% (RSD = 0.028) for these two chiral drugs at an ee value of 23.1%, respectively.

Capillary electrophoresis using triple layer modified capillary facilitating salivary ion analyses: Application to search for potential stress markers induced by cold pressure test

In this study, we introduce a novel approach for the analysis of salivary ions using capillary electrophoresis (CE) with a triple-layer coated capillary. The capillary is sequentially coated with cationic silylating reagents, poly(vinylsulfonate), and polybrene to form a custom designed surface that effectively inhibits adsorption of protein matrix on the capillary inner wall and allows for reproducible ion analysis. For the CE with capacitively coupled contactless conductivity detection, we used suitable background electrolytes (BGEs) for salivary ion analysis. Anions were separated using a mixture of 2-(N-morpholino)ethanesulfonic acid and l-arginine, and cations were separated using that with 18-crown-6. This setup enabled rapid separation, within 4 min, together with sensitive detection. We quantified nine common anions and five cations typically found in saliva samples using this CE method, both before and after a cold pressure test (CPT, a standard stress test). The CE system demonstrated consistent ion separation across 30 consecutive measurements without requiring capillary replacement. Notably, the salivary ion balance remained predominantly anion-rich, regardless of the CPT. Cold water exposure induced greater variation in the total anion concentration than in the total cation concentration. Further analysis using multiple regression analysis revealed strong relationships between nitrate and nitrite, formate and phosphate, and potassium and nitrate, before and after the CPT. Notably, potassium and nitrate ions exhibited variations in response to stress. These results provided a method for assessing salivary ion composition and insights into the potential of salivary ions as biomarkers for stress.

Development of the CE-C4D method for determination of organic acids in infants faeces using an in-house built instrument

Short-chain fatty acids (SCFAs) are a major group of products produced during colonic bacterial fermentation of nondigestible carbohydrates demonstrating several important functions, e.g. regulating the immune system activity or the lipid metabolism. A detailed profile and concentration characterization of SCFAs in infant faeces is essential for expanding knowledge regarding the role of SCFAs in infant physiology and pathophysiology. This research presents the development and validation of a capillary electrophoresis method with a contactless capacitively coupled conductivity detector (CE-C4D) for the analysis of SCFAs and succinic and lactic acids in infant faeces. The study focused on optimizing the background electrolyte, mainly dynamic capillary coating with polybrene, and utilizing cyclodextrins to achieve efficient separation. Validation parameters, such as linearity (0.993 – 0.998), limits of detection and quantification (LOD: 0.10 – 0.89 μg/mL; LOQ: 0.35 – 2.97 μg/mL), intra- and inter-day precision (1.71 – 5.69 % and 1.11 – 12.5 %, respectively), injection repeatability (0.91 – 5.70 %), trueness (-12.8 – 3.80 %), and matrix effect (78.8 – 108.6 %), were assessed and the method was found suitable for the purpose. The demonstrated method was successfully applied to determine nine organic acids in faecal samples.

HbA1c As Diabetes Mellitus Biomarker and Its Methods Evolution

This literature aims to review various aspects of HbA1c as a Diabetes Mellitus (DM) biomarker and various HbA1c examination methods and their respective advantages and limitations. Diabetes mellitus is a condition characterized by chronic hyperglycemia and can lead to microvascular and macrovascular complications in the future. HbA1c has been used extensively over the last few decades to monitor glycemic control and assess microvascular and macrovascular risk. It has also been used as one of the diagnostic criteria for DM. HbA1c is hemoglobin A, which is glycated at the N terminal of its valine beta-globin chain and provides an overview of glycemic control over the past three months. HbA1c is often reported using % or mmol/mol units and can be adjusted to assess the average blood glucose level over the past three months. Various methods developed for HbA1c examination include immunoassay, boronate affinity, enzymatic, capillary electrophoresis, and Ion-Exchange High-Performance Liquid Chromatography (IE-HPLC), and each has its advantages and limitations. In addition to their advantages in detecting HbA1c, the capillary electrophoresis and IE-HPLC methods can also detect other types of hemoglobin and the presence of hemoglobin variants.

Affinity Capillary Electrophoresis as a Tool To Characterize Molecularly Imprinted Nanogels in Solution.

In this work, an innovative and accurate affinity capillary electrophoresis (ACE) method was set up to monitor the complexation of aqueous MIP nanogels (NGs) with model cancer-related antigens. Using α2,6'- and α2,3'-sialyllactose as oversimplified cancer biomarker-mimicking templates, NGs were synthesized and characterized in terms of size, polydispersity, and overall charge. A stability study was also carried out in order to select the best storage conditions and to ensure product quality. After optimization of capillary electrophoresis conditions, injection of MIP NGs resulted in a single, sharp, and efficient peak. The mobility shift approach was applied to quantitatively estimate binding affinity, in this case resulting in an association constant of K ≈ 106 M-1. The optimized polymers further displayed a pronounced discrimination between the two sialylated sugars. The newly developed ACE protocol has the potential to become a very effective method for nonconstrained affinity screening of NG in solution, especially during the NG development phase and/or for a final accurate quantitation of the observed binding.

CE methods for charge variant analysis of mAbs and complex format biotherapeutics.

Charge heterogeneity analysis of monoclonal antibodies (mAbs) and complex formats, such as bispecifics, is crucial for therapeutic applications. In this study, we developed two capillary electrophoresis (CE)-based methods, capillary zone electrophoresis (CZE) and imaged capillary isoelectric focusing (iCIEF), for analyzing a broad spectrum of mAbs and complex mAb formats. For CZE, we introduced a new buffer system and optimized the background electrolyte (BGE) with an alternative dynamic coating agent and a superior polymeric additive. The pH of the BGE was increased, leading to enhanced resolution of high pI and complex format mAbs. In iCIEF, we identified an ampholyte combination offering a highly linear pH gradient and covering a suitable pH range. We also investigated alternatives to denaturing stabilizers and found that non-detergent sulfobetaine 195 exhibited excellent properties for iCIEF applications. These optimized methods provide a framework for the charge heterogeneity analysis of therapeutic mAbs and complex formats.

Capillary electrokinetic chromatography for chiral separation of potential SARS-CoV-2 3CL protease inhibitors.

In this work, a capillary electrophoresis method was developed as a quality control tool to determine the enantiomeric purity of a series of five chiral compounds evaluated as potential severe acute respiratory syndrome coronavirus 2 3CL protease inhibitors. The first cyclodextrin tested, that is, highly sulfated-β-cyclodextrin, at 6% (m/v) in a 25mM phosphate buffer, using a capillary dynamically coated with polyethylene oxide, at an applied voltage of 15kV and a temperature of 25°C, was found to successfully separate the five derivatives. The limits of detection and quantification were calculated together with the greenness score of the method in order to evaluate the method in terms of analytical and environmental performance. In addition, it is noteworthy that simultaneously high-performance liquid chromatography separation of the enantiomers of the same compounds with two different columns, the amylose tris(3,5-dimethylphenylcarbamate)-coated and the cellulose tris(3,5-dichlorophenylcarbamate)-immobilized on silica stationary phases, was studied. Neither the former stationary phase nor the latter was able to separate all derivatives in a mobile phase consisting of n-heptane/propan-2-ol 80/20 (v/v).

The separation of cyclic diadenosine diphosphorothioate and the diastereomers of its difluorinated derivative and the estimation of the binding constants and ionic mobilities of their complexes with 2-hydroxypropyl-β-cyclodextrin by affinity capillary electrophoresis.

The incorporation of phosphorothioate linkages has recently been extensively employed in therapeutic oligonucleotides. For their separation and quality control, new high-efficient and high-sensitive analytical methods are needed. In this work, a new affinity capillary electrophoresis method has been developed and applied for the separation of a potential anticancer drug, 2',3'-cyclic diadenosine diphosphorothioate (Rp , Rp ) (ADU-S100), and three recently newly synthesized diastereomers of its difluorinated derivative, 3',3'-cyclic di(2'-fluoro, 2'-deoxyadenosine phosphorothioate). The separation was performed in the various background electrolytes (BGEs) within a pH range 5-9 using several native and derivatized cyclodextrins (CDs) as chiral additives of the BGE. Relatively good separations were obtained with β-, γ-, and 2-hydroxypropyl-γ-CDs in some of the BGEs tested. However, the best separation was achieved using the 2-hydroxypropyl-β-CD chiral selector at 43.5mM average concentration in the BGE composed of 40mM Tris, 40mM tricine, pH 8.1. Under these conditions, all the previous four cyclic dinucleotides (CDNs) were baseline separated within 4min. Additionally, the average apparent binding constants and the average actual ionic mobilities of the complexes of all four CDNs with 2-hydroxypropyl-β-CD in the above BGE were determined. The formed complexes were found to be relatively weak, with the average apparent binding constants in the range of 12.2-94.1Lmol-1 and with the actual ionic mobilities spanning the interval (-7.8 to -12.7)×10-9 m2 V-1 s-1 . The developed method can be applied for the separation, analysis, and characterization of the above and similar CDNs.

Versatile capillary electrophoresis method for the direct chiral separation of aliphatic and aromatic α-hydroxy acids, β-hydroxy acids and polyhydroxy acids using vancomycin as chiral selector

Hydroxy acids (HAs) are ubiquitous in nature and play significant roles in various industrial and biological processes. Most HAs harbor at least one chiral center, therefore the development of efficient chiral analysis techniques for HA stereoisomers is of crucial importance across a wide range of fields. A capillary electrophoresis (CE) method was developed for the chiral analysis and quantification of aliphatic and aromatic α-hydroxy acid (AHA) enantiomers, aliphatic β-hydroxy acid (BHA) enantiomers and aliphatic polyhydroxy acid (PHA) stereoisomers. Using a modified partial filling-counter current method with indirect UV detection, high resolution (Rs) was achieved with vancomycin as a chiral selector added to the background electrolyte composed of 10 mM of benzoic acid/L-histidine at pH 5 using a polyacrylamide-coated capillary. This method could be readily applied to the determination of the enantiomers of 12 aliphatic AHAs, 4 aromatic AHAs, 3 aliphatic BHAs, as well as to the determination of the stereoisomers of tartaric acid, 2,3-dihydroxybutanoic acid, 2,3,4,5-tetrahydroxypentanoic acid, and 2,3,4,5,6-pentahydroxyhexanoic acid without the need for sample derivatization. Finally, our study provides a robust and versatile strategy for the chiral and stereoselective analysis of a broad range of hydroxy acid compounds.

SUB-MINUTE CAPILLARY ZONE ELECTROPHORESIS METHOD FOR DETERMINATION OF HYDROCHLOROTHIAZIDE IN COMBINATION WITH OTHER ACTIVE INGREDIENTS IN NINE DIFFERENT PHARMACEUTICAL SAMPLES

Capillary electrophoresis (CE) methods have unique potential for applications in quality control of pharmaceutical formulations. Here, we show that a single and ultra-fast CE method can be used for the determination of hydrochlorothiazide (HCT) in combination with nine other active ingredients in a single run in different pharmaceutical samples: atenolol (ATE), metoprolol (MET), propranolol (PRO), benazepril (BEN), captopril (CAP), enalapril (ENA), lisinopril (LIS), ramipril (RAM), and valsartan (VAL). This goal was achieved using a single and simple background electrolyte (BGE) composed of 10 mmol L-1 of boric acid with pH adjusted to 9.0 with sodium hydroxide. All samples can be analyzed in less than 1 min with the attainment of good analytical performance, such as high-resolution separation (r > 1.3), low sample and reagents consumption (environmentally friendly method), low relative standard deviation (RSD) values for peak area (< 4.0%) and migration times (< 1.7%), and linear relationships with good correlation coefficients (> 0.995). Furthermore, recovery tests showed good results (100 ± 5%) for all evaluated compounds.

Quantitative separation of polystyrene nanoparticles in environmental matrices with picogram detection limits using capillary electrophoresis.

We developed a capillary electrophoresis method to separate polystyrene particles (PSPs) with different sizes or different surface functionalities. Separations were performed in buffer and 100 mg L-1 clay or 100 mg L-1 Suwanee River humic acid. In all solutions, PSPs were baseline or near-baseline resolved in less than 15 minutes.