A capillary column coated with 3-aminophenylboronic acid (APBA)-functionalized gold nanoparticles (AuNPs@APBA) was prepared via electrostatic self-assembly. The coated column exhibited anti-nonspecific adsorption of glycoproteins, enabling selective online enrichment during capillary electrophoresis (CE). First, gold nanoparticles (AuNPs) were synthesized using the sodium citrate reduction method. Then, APBA was self-assembled electrostatically on the surface of the AuNPs to obtain AuNPs@APBA. This nanomaterial was bonded to the inner wall of a capillary through ion adsorption to produce a AuNPs@APBA-coated capillary column. Glycoproteins were adsorbed via bond formation with boric acid groups under alkaline conditions (pH 8) to generate borate esters. Under acidic conditions (pH 3), the borate esters dissociated to release the glycoproteins, thereby achieving the selective online enrichment and separation of glycoproteins. The AuNPs and AuNPs@APBA were characterized using Fourier transform infrared spectroscopy, and their sizes and Zeta potentials were determined. In addition, the electroosmotic flow (EOF) of the AuNPs@APBA-coated capillary column was measured. The results showed that the surface of the AuNPs was successfully modified with APBA and that AuNPs@APBA was adsorbed on the inner wall of the capillary. The peak area of ovalbumin (OVA) on the AuNPs@APBA-coated column was 26.46 times higher than that on a bare column via conventional electrophoresis. In contrast, the peak area of bovine serum albumin (BSA) only increased by 8.47 times, indicating that the AuNPs@APBA coated column selectively enriched glycoproteins. Evaluation of the reproducibility and stability of this method revealed that the AuNPs@APBA coated capillary column could be used continually for 33-67 h. The relative standard deviations (RSDs) of the peak areas for intra-day (n=5) and inter-day (n=6) analyses were 2.2% and 3.0%, respectively. The developed method was successfully applied to enrich glycoproteins in a 1×106-fold diluted egg white sample. Glycoproteins were not detected using conventional electrophoresis on the bare column, whereas the AuNPs@APBA-coated capillary column effectively enriched and separated glycoproteins, resulting in a peak area of 10469 mAU·ms. Furthermore, the entire enrichment and separation process was completed within 3 min. This new online enrichment and separation method for glycoproteins has the advantages of low sample consumption, simple operation, and high separation efficiency.

Fluorescent whitening agents (FWAs) are dyes that emit visible blue or blue-purple fluorescence upon ultraviolet-light absorption. Taking advantage of light complementarity, FWAs can compensate for the yellow color of many substances to achieve a whitening effect; thus, they are used extensively in various applications. FWAs are generally stable, but their presence in the environment can lead to pollution and accumulation in the body through the food chain. Recent studies have revealed that some types of FWAs, such as coumarin-based FWAs, may exhibit photo-induced mutagenic effects that can trigger allergic reactions in humans and even pose carcinogenic risks. Hence, the development of an accurate and highly sensitive method for detecting FWAs in food-related samples is a crucial endeavor. Owing to the high polarity and structural similarity of FWAs, the accurate determination of these substances in complex food samples requires an analytical method that offers both efficient separation and sensitive detection. Capillary electrophoresis (CE) exhibits essential features such as high separation efficiency, short analysis times, very small sample injection requirements, minimal use of organic solvents, and simple operation. Thus, it is often used as an effective alternative to liquid chromatographic techniques. Over the past few decades, electrospray ionization mass spectrometry (ESI-MS) has been utilized as a highly sensitive and accurate detection method in numerous chemical analytical fields because it enables the analysis of molecular structures. By combining the high separation efficiency of CE with the high sensitivity of ESI-MS, a powerful tool for identifying and quantifying trace amounts of FWAs in food samples may be obtained. In this study, we present a method based on sheathless CE coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) for the simultaneous detection of six trace FWAs in flour. In the proposed method, the CE separation device is directly coupled to the mass spectrometer through a sheathless interface without the need for a sheath liquid for electric contact, thereby avoiding the dilution of the analytes and improving detection sensitivity. Various conditions that could affect extraction recovery, separation efficiency, and detection sensitivity were evaluated and optimized. The FWAs were effectively extracted from the sample matrix with reduced matrix effects by ultrasonic-assisted extraction at a temperature of 30 ℃ for 20 min using CHCl3-MeOH (3∶2, v/v) as the extraction solvent. The extract was centrifuged, dried under N2, and reconstituted in CHCl3-MeOH (1∶4, v/v) for subsequent analysis. During the detection process, the CE device was coupled to the ESI-MS/MS instrument via a highly sensitive porous spray needle, which served as the sheathless electrospray interface. The target FWAs were scanned in positive-ion mode (ESI+) to ensure the stability and intensity of the obtained signals. Additionally, multiple-reaction monitoring (MRM) mode and MS/MS analysis were used to simultaneously quantify the six targets with high selectivity. The developed sheathless CE-ESI-MS/MS method detected the FWAs with high sensitivity over wide linear ranges with low method limits of detection (0.04-0.67 ng/g). The recoveries of the six target FWAs at three spiked levels were between 77.5% and 97.2%, with good interday (RSD≤11.5%) and intraday (RSD≤10.2%) precision. Analyses of the six target FWAs in eight commercial flour samples were performed using this method, and four positive samples were identified. These results demonstrate that the proposed CE-ESI-MS/MS method is a promising strategy for the determination of trace FWAs in complex food sample matrices with efficient separation and high sensitivity.

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.

The physical and chemical properties of chiral drugs are very similar. However, their pharmacological and toxicological effects vary significantly. For example, one enantiomer may have favorable properties whereas the other may be ineffective or even have toxic side effects. Hence, exploring innovative strategies to improve enantiomeric resolution is of great importance. Metoprolol (MET) is a β-receptor blocker used to treat hypertension, stable angina pectoris, and supraventricular tachyarrhythmia. Establishing chiral separation and analysis methods of MET enantiomers is important for enhancing the quality of chiral drugs. Capillary electrophoresis (CE) has the advantages of a small sample size, simple operation, high separation efficiency, and many alternative modes; therefore it is widely used in the field of chiral drug separation. The chiral selectors commonly used for CE-based chiral separation include cyclodextrin (CD) and its derivatives, polysaccharides, proteins, and macrocyclic antibiotics. CD is one of the most commonly used and effective chiral selectors for CE. The relatively hydrophobic structure inside the cavity and the relatively hydrophilic structure outside the cavity of CD enable it and chiral molecules to form inclusion compounds with different binding constants, thus achieving chiral separation. However, the use of CD alone as a chiral selector does not always yield satisfactory separation results. Hence, the addition of other additives, such as ionic liquids and deep eutectic solvents (DESs) to assist CD-based chiral separation systems has received extensive attention. Previous studies on the enantiomeric separation of MET by CE have focused on the addition of CD and its derivatives alone for separation. Few studies have been conducted on the synergistic addition of auxiliary additives to CD to improve the enantiomeric resolution of MET. In this study, three DESs, namely, choline chloride-D-glucose, choline chloride-D-fructose, and lactate-D-glucose, were used for the CE-based chiral separation of MET for the first time, and the synergistic effect of the DESs on the separation of MET enantiomers by CD-based capillary zone electrophoresis was speculated. For this purpose, an uncoated fused silica capillary with inner diameter of 50 μm, total length of 50 cm and effective length of 41.5 cm was used as the separation column. First, the effects of CD type, CD concentration, buffer pH, and buffer concentration on MET separation were investigated, and the optimal conditions (15 mmol/L carboxymethyl-β-cyclodextrin (CM-β-CD), pH=3.0, and 40 mmol/L phosphate buffer) were obtained. Other CE conditions were as follows: UV detection at 230 nm, applied voltage of 25 kV. All operations were carried out at 20 ℃. Next, three types of DESs were prepared as auxiliary additives via a mixed-heating method. The DESs were mixed in a 50 mL round-bottomed flask at a certain molar ratio and then heated in a water bath at 80 ℃ for 3 h until a clear and transparent liquid was obtained. The effects of different DESs and their mass fraction on chiral separation were subsequently studied. The optimal choline chloride-D-fructose mass fraction was ultimately determined to be 1.5%. The resolution of MET increased from 1.30 without DES to 2.61 with 1.5% choline chloride-D-fructose, thereby achieving baseline separation. Finally, the separation effect and mechanism were speculated. The MET chiral separation method established in this study is of great significance for improving the quality of chiral compounds and ensuring the safety and effectiveness of clinical drugs. Furthermore, it may be useful in the research and development of CE-based chiral separation techniques using CD derivatives with DESs.

Pancreatic cystic disease, including duct dilation, represents precursor states towards the development of pancreatic cancer, a form of malignancy with relatively low incidence but high mortality. While most of these cysts (>85%) are benign, the remainder can progress over time, leading to malignant transformation, invasion, and metastasis. Cytologic diagnosis is challenging, limited by the paucity or complete absence of cells representative of cystic lesions and fibrosis. Molecular analysis of fluids collected from endoscopic-guided fine-needle aspiration of pancreatic cysts and dilated duct lesions can be used to evaluate the risk of progression to malignancy. The basis for the enhanced diagnostic utility of molecular approaches is the ability to interrogate cell-free nucleic acid of the cyst/duct and/or extracellular fluid. The allelic imbalances at tumor suppressor loci and the selective oncogenic drivers are used clinically to help differentiate benign stable pancreatic cysts from those progressing toward high-grade dysplasia. Methods are discussed and used to determine the efficacy for diagnostic implementation. Here, we report the analytical validation of methods to detect causally associated molecular changes integral to the pathogenesis of pancreatic cancer from pancreatic cyst fluids.

Guanosine triphosphate (GTP) and adenosine triphosphate (ATP) are essential nucleic acid building blocks and serve as energy molecules for a wide range of cellular reactions. Cellular GTP concentration fluctuates independently of ATP and is significantly elevated in numerous cancers, contributing to malignancy. Quantitative measurement of ATP and GTP has become increasingly important to elucidate how concentration changes regulate cell function. Liquid chromatography-coupled mass spectrometry (LC-MS) and capillary electrophoresis-coupled MS (CE-MS) are powerful methods widely used for the identification and quantification of biological metabolites. However, these methods have limitations related to specialized instrumentation and expertise, low throughput, and high costs. Here, we introduce a novel quantitative method for GTP concentration monitoring (GTP-quenching resonance energy transfer (QRET)) in homogenous cellular extracts. CE-MS analysis along with pharmacological control of cellular GTP levels shows that GTP-QRET possesses high dynamic range and accuracy. Furthermore, we combined GTP-QRET with luciferase-based ATP detection, leading to a new technology, termed QT-LucGTP&ATP, enabling high-throughput compatible dual monitoring of cellular GTP and ATP in a homogenous fashion. Collectively, GTP-QRET and QT-LucGTP&ATP offer a unique, high-throughput opportunity to explore cellular energy metabolism, serving as a powerful platform for the development of novel therapeutics and extending its usability across a range of disciplines.

Despite the fact that the self-disproportionation of enantiomers (SDE) has been found for several decades and has been widely used in crystallization, sublimation and chromatography for the purification or separation of nonracemic compounds, the phenomenon of SDE in capillary electrophoresis (CE) has never been reported up to now. Here, a new approach to separate enantiomers in CE based on SDE was demonstrated by introducing copper (II) ions into the separation media. The enantiomers of atenolol interact with copper ions to produce positively charged complexes with different electrophoretic mobilities from the single molecules. The dynamic equilibrium between homo- or heterochiral complexes (associates) and single molecules of atenolol enantiomers supports the manifestation of SDE. Different mobilities of the single molecules and associates, and different distribution of two enantiomers between the single molecules and associates caused by their different concentrations, produce a net difference in electrodriven migration velocities of the two enantiomers. The relative movement of two enantiomers causes a zone depleted in one enantiomer at the rear end of sample segment, giving a trapezoidal CE curve with a step at the end. Quantification of enantiomers is achieved according to the step height. The analysis does not rely on the use of enantiomerically pure chiral selector and the result agrees with that obtained by conventional chiral CE using a chiral selector.

Diabetic foot is a serious late complication frequently caused by infection and ischaemia. Both require prompt and aggressive treatment to avoid lower limb amputation. The effectiveness of peripheral arterial disease therapy can be easily verified using triplex ultrasound, ankle-brachial/toe-brachial index examination, or transcutaneous oxygen pressure. However, the success of infection treatment is difficult to establish in patients with diabetic foot. Intravenous systemic antibiotics are recommended for the treatment of infectious complications in patients with moderate or serious stages of infection. Antibiotic therapy should be initiated promptly and aggressively to achieve sufficient serum and peripheral antibiotic concentrations. Antibiotic serum levels are easily evaluated by pharmacokinetic assessment. However, antibiotic concentrations in peripheral tissues, especially in diabetic foot, are not routinely detectable. This review describes microdialysis techniques that have shown promise in determining antibiotic levels in the surroundings of diabetic foot lesions.

This article provides a detailed review of capillary electrophoresis (CE) technology in 2022, summarizing a total of 881 CE technology-related articles searched from ISI Web of Science using the keywords \"capillary electrophoresis mass spectrometry\" or \"capillary isoelectric focusing\" or \"micellar electrokinetic chromatography\" or \"capillary electrophoresis\" (excluding \"capillary electrochromatography\"\"microchip\" \"microfluidic\" \"capillary monolithic column\"). The review focuses on 16 articles published in Lancet Global Health, ACS Central Science, Microbiome, Trends in Food Science & Technology, TrAC-Trends in Analytical Chemistry, Journal of Pharmaceutical Analysis, Journal of Cachexia, Sarcopenia and Muscle, Food Hydrocolloids, Science of the Total Environment, and Carbohydrate Polymers with impact factors (IFs) greater than 10.0, and 46 articles published in Analytical Chemistry, Analytica Chimica Acta, Talanta, and Food Chemistry with IFs between 5.0 and 10.0. A comprehensive overview of representative CE works published in Journal of Chromatography A, Electrophoresis, and important Chinese core journals (Peking University) with IFs<5.0 is also provided. Based on IFs, this review introduces representative works on CE to facilitate readers\' understanding of important research advances in CE technology over the last year.

Insertion/deletion polymorphisms (InDels) have been treated as a prospective and helpful genetic marker in the fields of forensic human identification, anthropology and population genetics for the past few years. In this study, we developed a six-dye multiplex typing system consisting of 34 autosomal InDels and Amelogenin for forensic application. The contained InDels were specifically selected for Chinese population with the MAF ≥ 0.25 in East Asia, which do not overlap with the markers of Investigator® DIPplex kit. The typing system was named as GoldeneyeTM DNA ID System 35InDel Kit, and a series of developmental validation studies including repeatability/reproducibility, concordance, accuracy, sensitivity, stability, species specificity and population genetics were conducted on this kit. We confirmed that the 35InDel kit is precise, sensitive, species specific and robust for forensic practice. Moreover, the 35InDel kit is capable of typing DNA extracted from forensic routine case-type samples as well as degraded samples and mixture samples. All markers are proved to be highly polymorphic with an average observed heterozygosity (He) of 0.4582. The combined power of discrimination (CPD) is 0.999 999 999 999 978 and the combined power of exclusion in duos (CPED) and trios (CPET) are 0.978 837 and 0.999573, respectively, which are higher than those of the Investigator® DIPplex kit. Thus, the GoldeneyeTM DNA ID System 35InDel kit is suitable for forensic human identification and could serve as a supplementary typing system for paternity testing. Supplemental data for this article is available online at https://doi.org/10.1080/20961790.2021.1945723 .