Se pu = Chinese journal of chromatography最新文献

{"title":"[Vacuum ultraviolet laser dissociation and proteomic analysis of halogenated peptides].","authors":"Pan Luo, Jie-Ying Xue, Zhe-Yi Liu, Fang-Jun Wang","doi":"10.3724/SP.J.1123.2024.08009","DOIUrl":"10.3724/SP.J.1123.2024.08009","url":null,"abstract":"<p><p>Chemical modifications are widely used in research fields such as quantitative proteomics and interaction analyses. Chemical-modification targets can be roughly divided into four categories, including those that integrate isotope labels for quantification purposes, probe the structures of proteins through covalent labeling or cross-linking, incorporate labels to improve the ionization or dissociation of characteristic peptides in complex mixtures, and affinity-enrich various poorly abundant protein translational modifications (PTMs). A chemical modification reaction needs to be simple and efficient for use in proteomics analysis, and should be performed without any complicated process for preparing the labeling reagent. High reaction specificity, which reduces product complexity, and mild biocompatible reaction conditions are also favored. In addition, modification labels should be compatible with mass spectrometry to prevent interference from ionization and dissociation processes. Pulsed ultraviolet (UV) lasers can produce large amounts of active radical species within a few nanoseconds for use in rapid photochemical-modification processes. Usually, UV lasers with wavelengths greater than 240 nm are used in current in-situ photochemical-modification methods; consequently, special conjugated photoreaction probes need to be designed and oxidants and catalysts added, which reduce the biocompatibility of the reaction. The high single-photon energy of the 193 nm laser is capable of efficiently exciting conventional photo-inert substances in aqueous solution, leading to efficient photochemical peptide modifications. In this study, we developed a new method for photochemically brominating and iodinating enzymatic protein samples extracted from complex tissue with a 193 nm ArF nanosecond pulsed laser, which efficiently brominated tyrosine, histidine, and tryptophan, and iodinated tyrosine and histidine. Tandem mass spectrometry (MS/MS) can generate fragmentation patterns of ions which can afford diagnostic molecular fingerprints to decipher sequences of biopolymers such as peptides. Peptide fragmentation is commonly implemented using collision-based, electron-based, or photodissociation-based methods. Compared with the most commonly used collision-based methods, ultraviolet photodissociation (UVPD) uses high-energy ultraviolet photons with wavelengths shorter than 200 nm to excite and dissociate ions. Single-pulse excitation can provide the energy required to promote ions into their excited electronic states, with excitation speeds of up to several nanoseconds. Since dissociation may occur directly from the excited states, UVPD spectra can show a wide variety of fragmentation pathways, thereby providing more sequence and structural information. The most commonly used wavelengths are 157, 193, and 266 nm. UVPD has been integrated into high-resolution orbitrap mass spectrometer by adding optical windows and other optics to direct the photons to the ","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"131-138"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11755738/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Analysis of ischemic stroke biomarkers based on non-targeted metabolomics].","authors":"Fei Xu, Tian-Ping Liu, Ya-Jin Guan, Wei-Chao Hao, Ding-Sheng Wen, Shui-Lin Xie, Ya-Nan Bie","doi":"10.3724/SP.J.1123.2024.02015","DOIUrl":"10.3724/SP.J.1123.2024.02015","url":null,"abstract":"<p><p>Biomarkers for ischemic stroke (IS) are yet to fulfill clinical requirements. This study used non-targeted metabolomics to investigate differential metabolites and metabolic pathways in plasma and brain tissue following IS, with the aim of identifying new potential biomarkers and therapeutic targets. Twelve Tibetan miniature pigs were randomly assigned to a model- or sham-operation group. An electrocoagulation-based anterior temporal approach was employed to occlude the middle cerebral artery, thereby creating a model for IS. Plasma and brain tissue samples were collected 36 h post-surgery and analyzed using liquid chromatography-mass spectrometry. Principal component and partial least squares discriminant analyses were used to screen for differential metabolites and exclude exogenous metabolites at <i>p</i><0.05. Compounds were classified according to the HMDB (Human Metabolome Database), and subjected to KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway and VIP (variable importance in projection) analyses. Plasma metabolomics revealed that 86 metabolites were upregulated while 149 were downregulated, with (<i>Z</i>)-3-oxo-2-(2-pentenyl)-1-cyclopentylacetic acid, <i>trans</i>-cinnamic acid and cinnamoylglycine determined to be significant metabolites. Fifty-eight differential metabolites were upregulated in brain tissue and 53 were downregulated, with 2,3-dihydroflavon-3-ol, guanidinoacetic acid (GAA), <i>N</i>-acetyl-D-tryptophan, oxidized glutathione, 2-hydroxyquinoline, and <i>N</i>-acetyl-L-aspartate (NAA) identified as significant metabolites. Organic acids and derivatives, lipids and lipid-like molecules, organoheterocyclic compounds, and organic oxygen compounds were found to be common compound categories among the top five types of compound in both plasma and brain tissue. Common metabolic pathways in plasma and brain tissue include amino acid metabolism, digestive system, cancer overview, and lipid metabolism pathways, with the (<i>Z</i>)-3-oxo-2-(2-pentenyl)-1-cyclopentylacetic acid, GAA, oxidized glutathione, and NAA metabolites serving as potential biomarkers. This study provides a theoretical foundation for the early screening and development of clinical treatment strategies for IS.</p>","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"139-147"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11758226/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Simultaneous determination of 51 indazole-type synthetic cannabinoids in urine and blood by online solid-phase extraction-liquid chromatography-linear ion trap mass spectrometry].","authors":"Xuan Luo, Jun Zhang, Ding-Ji Zhu, Ke-Jian Huang, Ning Yang, Xiao-Feng Liu, Qiu-Lian Luo","doi":"10.3724/SP.J.1123.2024.02008","DOIUrl":"10.3724/SP.J.1123.2024.02008","url":null,"abstract":"&lt;p&gt;&lt;p&gt;To evade legal controls, new psychoactive substances (NPS), which have been designed as substitutes for traditional and synthetic drugs, are gradually dominating the drug market. Synthetic cannabinoids (SCs), which account for the majority of NPS, are rapidly being derivatized; consequently, controlling increasing abuse by merely listing individual compounds is difficult. Therefore, China has included the entire SC category of SCs listed as legal controlled substances since July 1, 2021. However, new SCs obtained through structural modification are still appearing and pose significant analytical challenges for forensic laboratories. Therefore, an efficient, green, and automated detection method is urgently required to provide technical support for the accurate screening actual samples. Meanwhile, the number of indazole-type SCs has increased sharply since 2013, which is ascribable to their stronger psychoactive effects. Indeed, forensic laboratories mainly analyze this key SC subclass. Therefore, in this study, we developed a new method for analyzing 51 indazole-type SCs in human urine and blood, which involves online solid-phase extraction (online SPE) as the preprocessing technology, with analysis performed using liquid chromatography-linear ion trap mass spectrometry. Deproteinization was achieved by adding acetonitrile, with dilution performed using 10 mmol/L ammonium acetate solution (pH 4.8) containing 0.1% formic acid. Samples were then analyzed directly using acetonitrile-10 mmol/L ammonium acetate aqueous solution (containing 0.1% formic acid) as the mobile phase. The mass-to-charge ratios of protonated molecular ions ([M+H]&lt;sup&gt;+&lt;/sup&gt;) in the mass spectra acquired in full-scan mode, and the retention times in the chromatograms of the analytes were selected with the aim of monitoring the MS&lt;sup&gt;2&lt;/sup&gt; ions of the various compounds. Characteristic fragment ions of the various SC structures were summarized, with five groups of isomers, each containing ten compounds, successfully distinguished using multistage mass spectrometry and their retention times. Multistage MS was used to qualitatively screen 51 indazole-type SCs, which were then quantitatively analyzed using MS&lt;sup&gt;2&lt;/sup&gt; ion pairs (as quantitative ion pairs). The analytes exhibited limits of detection (LODs) of 0.02-1 ng/mL, with limits of quantification (LOQs) of 0.04-4 and 0.1-4 ng/mL in urine and blood, respectively. Linear fitting (weighting factor 1/&lt;i&gt;x&lt;/i&gt;) revealed good linearity for each analyte within its respective linear range, with correlation coefficients (&lt;i&gt;R&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt;) greater than 0.99 in both urine and blood. The validity of the analytical method was tested by determining precision and spiked recovery values (&lt;i&gt;n&lt;/i&gt;=6). Recoveries of 83.47%-116.95% were obtained at LOQ levels, with precisions of 2.29%-13.40%. In addition, recoveries of 86.63%-113.38% and precisions of 0.58%-13.79% were obtained at low, medium, and high levels. The method describ","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"164-176"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11758235/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Design and evaluation of a liquid chromatographic column oven with adaptive and precise temperature control].","authors":"Xing-Fa Ren, Feng-Wei Shao, Yong Wu, Xin-Ming Liao, Zhuo Wang, Lin-Juan Zhou, Xu-Hong He, Wei-Bing Zhang","doi":"10.3724/SP.J.1123.2023.11021","DOIUrl":"10.3724/SP.J.1123.2023.11021","url":null,"abstract":"<p><p>High performance liquid chromatography (HPLC) is a key analytical technique that is used in a number of fields. Improving the separation efficiency, stability, and universality of HPLC has been a continuing analytical-chemistry focus. In chromatographic separation, factors such as the composition and ratio of the mobile phase, the type of stationary phase, and the dimensions of the chromatographic column significantly affect the separation efficiency. In addition, the temperatures of the chromatographic column and mobile phase are also important for achieving separation. The column oven is usually used to stably control the column temperature in the HPLC separation system. Indeed, highly accurate temperature control ensures superior separation performance, short analysis times, and repeatability. In this study, we innovatively improved the traditional column oven by combining a variety of temperature-control algorithms to deliver continuous and highly accurate temperature control in the wide 4-90 ℃ range, and by exploring a new chromatographic-method development route. Instead of focusing on the complex hardware system, we optimized the software to achieve highly stable and accurate (±0.1 ℃) temperature control. Temperature-control performance was further improved by optimizing the structure of the thermal insulation and employing reliable and environmentally friendly thermal-insulation materials. Additionally, the thermal conduction of the heat-source device is discussed based on the heat-transfer principle with the aim of improving the performance of the column oven. The improved column oven delivered significantly enhanced chromatographic-separation repeatability and stability thereby reliably guaranteeing the development of highly efficient chromatographic analysis methods.</p>","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"177-184"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11755736/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Recent progress in magnetic covalent organic framework materials for the enrichment and detection of typical organic pollutants].","authors":"Liu-Shan Jiang, Qing-Xiang Zhou","doi":"10.3724/SP.J.1123.2024.07020","DOIUrl":"10.3724/SP.J.1123.2024.07020","url":null,"abstract":"<p><p>Trace contaminants are toxic and their widespread presence in the environment potentially threatens human health. The levels of these pollutants are often difficult to determine directly using instruments owing to the complexities of environment matrices. Hence, pretreatment steps, such as sample purification and concentration, are key along with various processes that enhance the accuracy and sensitivity of the detection method. To date, researchers have successfully developed a variety of efficient and reliable sample-pretreatment techniques that are based on different principles. Among these, magnetic solid-phase extraction (MSPE) is a rapid and efficient sample-pretreatment technology that is based on the similar solid-phase-extraction (SPE) principle, which mainly enriches target analytes by exploiting their interactions with functional groups on the surfaces of magnetic materials, thereby achieving rapid separation when an external magnetic field is applied. MSPE has been a focus of attention in the environmental-sample-pretreatment, food-analysis, and other fields owing to advantages that include ease of operation, low cost, and high enrichment efficiency. The selection of the magnetic material is key to MSPE process because traditional magnetic materials exhibit certain functionality limitations. Accordingly, designing and synthesizing green and efficient functionalized magnetic materials have become a research focus in this field, with researchers having extensively explored multiple ways of preparing functionalized modified magnetic materials through the introduction of a variety of emerging materials, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), carbon nanotubes (CNTs), graphene oxide (GO), and other specific functional groups to modify magnetic materials and effectively expanded the applications scope of MSPE. Among these, COFs are porous crystalline materials consisting of light elements (C, N, H, O and B, etc.) linked through covalent bonds. COFs are mainly classified as imine COFs, boronic-acid COFs, triazine COFs, and ketenimine COFs according to bonding type. Moreover, it is worth mentioning that COFs can be synthesized from a number of monomers, and the functional groups exposed on the COF surface can also be used for further modification purposes. COFs are versatile and modifiable; consequently, they have attracted significant research attention, with a series of COF-functionalized magnetic materials having been designed and synthesized. The magnetic COFs (MCOFs) combine the advantages of COFs and magnetic materials. MCOFs are not only endowed with the large specific surface areas, high porosities, and good stabilities that are characteristic of COFs, but also exhibit the rapid separation and reusability characteristics of magnetic material, thereby quickly and efficiently enriching targets through hydrogen bonding, hydrophobicity, <i>π-π</i> stacking, and van der Waals forces, making the","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"107-119"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11758229/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Reform and exploration of the experimental teaching mode of teaching assistant and group rotation system: taking pharmaceutical analysis experiment course as an example].","authors":"Ran Zhao, Ling Zhang, Kun Zhang, You-Xin Li","doi":"10.3724/SP.J.1123.2024.03012","DOIUrl":"10.3724/SP.J.1123.2024.03012","url":null,"abstract":"<p><p>Experimental courses in pharmaceutical analysis are an important part of the training process for pharmaceutical talent. These courses focus on applying theoretical knowledge in practice and using large instruments, with the aim of inspiring innovative thinking and cultivating student development. Currently, several issues impede the success of experimental pharmaceutical analysis courses both in China and abroad. In domestic colleges and universities, the content of these courses varies significantly and is relatively unsophisticated. Owing to economic and human resource limitations, students lack training in the operation and use of large analytical instruments. In foreign universities, the range of professional instruments is not comprehensive, experimental class hours are limited, and the availability of large instruments for experimental teaching is insufficient. The School of Pharmaceutical Science and Technology, Faculty of Medicine, Tianjin University, explored the teaching assistant system with group rotation for the delivery of experimental pharmaceutical analysis courses. In combination with the large instrument sharing platform of the school, this approach resulted in a relatively comprehensive teaching model. This model reduced the demand for experimental instruments at a certain time by extending the time axis, thereby relieving the pressure on large instrument allocation. Furthermore, a complete pharmaceutical analysis teaching program was designed according to the curriculum requirements, covering common analytical methods and instruments used in pharmaceutical analysis. With guidance from experimental teaching assistants, students consolidated their theoretical knowledge, mastered key techniques for drug quality control and the drug research process, and laid a foundation for developing new drug analysis methods. Over years of continuous exploration, this model has matured to achieve good teaching outcomes. This work can provide a reference for the development of experimental pharmaceutical analysis courses in domestic universities.</p>","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 2","pages":"197-203"},"PeriodicalIF":0.0,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11755744/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143026275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Recent progress in mass spectrometry imaging using nanospray desorption electrospray ionization].","authors":"Jing-Bo Wang, Xiao-Lan Li, Rui-Xia Fan, Ping Lü, Rui-Chuan Yin","doi":"10.3724/SP.J.1123.2024.07013","DOIUrl":"10.3724/SP.J.1123.2024.07013","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Ambient mass spectrometry imaging (MSI) enables hundreds of analytes in tissue sections to be directly mapped at atmospheric pressure with minimal sample preparation. This field is currently experiencing rapid growth, with numerous reported ambient ionization techniques resulting in a \"hundred flowers bloom\" situation. Nanospray desorption electrospray ionization (nano-DESI), developed by the Laskin group in 2010, is a widely used liquid-extraction-based ambient ionization technique that was first used for mass spectrometry imaging of tissue in 2012. The nano-DESI probe comprises a primary capillary and a nanospray capillary, with the latter efficiently transferring analyte-containing droplets via a tiny liquid bridge formed between the probe and sample surface, thereby enabling nanoelectrospray ionization (nano-ESI) in front of the inlet of a mass spectrometer. The advantages of nano-DESI MSI include minimal sample preparation, high spatial resolution, and high sensitivity. These features are well-suited for imaging various sample types, including frozen tissue sections, microbial communities, and environmental samples. A PubMed-database search using the \"nano-DESI\" keyword revealed 72 related articles in the 2010-2024 period, with 34 of them published between 2021 and 2024, which indicates that nano-DESI has rapidly developed as an ambient ionization technique over recent years. Herein, we briefly introduce key nano-DESI-MSI research progress reported in the past three years with the aim of better understanding and facilitating the use of this technology. We first discuss advances in ion-source development. Since no commercial nano-DESI source exists, designing and constructing ion sources remain technical challenges that limit its development. Nano-DESI has been successfully coupled with various types of mass spectrometer, including LTQ Orbitrap, quadrupole-Orbitrap (Q Exactive), 6560 IM QTOF, timsTOF Pro2, triple quadrupole, and FTICR. These couplings have significantly expanded the applications range of the nano-DESI technique. Secondly, lipid analysis is a major nano-DESI-MSI applications area. While the complexities of lipid structures present great challenges for nano-DESI MSI, new nano-DESI coupling techniques have enabled the identification and imaging of fine lipid structures. Several novel imaging methods have recently been introduced to address difficulties associated with identifying lipid structures, such as distinguishing carbon-carbon double bonds (C=C) and &lt;i&gt;sn&lt;/i&gt;-positional isomers. We finally highlight recent research progress in the nano-DESI MSI of intact protein assembles and proteoforms, which is a growing hotspot in the field. Unlike small lipid molecules, large protein molecules are very challenging to image and consequently demand higher instrumental performance (e.g., ionization efficiency, mass range, and sensitivity). In a similar manner to the ESI technique, nano-DESI tends to generate multiply charged molec","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 1","pages":"43-49"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11686469/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Current advances in the analysis of free RNA modified nucleosides by high performance liquid chromatography-tandem mass spectrometry].","authors":"Lyu-Ye Zhang, Wei-Bing Zhang, Hai-Lin Wang","doi":"10.3724/SP.J.1123.2024.07004","DOIUrl":"10.3724/SP.J.1123.2024.07004","url":null,"abstract":"<p><p>Post-transcriptional ribonucleic acid (RNA) modifications play crucial roles in regulating gene expression, with both eukaryotic and prokaryotic RNA exhibiting more than 170 distinct and ubiquitous modifications. RNA turnover generates numerous free nucleosides, including unmodified nucleosides and a variety of modified ones. Unlike unmodified nucleosides, modified nucleosides are not further degraded or used in the salvage-synthesis pathway owing to a lack of specific enzymes, which leads to the cytosolic accumulation or cellular efflux of modified nucleosides. These modified nucleosides can act as signaling molecules that regulate downstream pathways once transported to the extracellular space; alternatively, they are metabolized in the bloodstream and excreted in urine. Metabolized modified nucleosides are altered by cellular stress responses and mediate abnormal physiological states. Changes in the urinary and blood levels of modified nucleosides associated with cancer can serve as biomarkers for disease. Therefore, identifying and accurately quantifying nucleosides is vital for understanding RNA degradation and associated patterns of nucleoside metabolism. Such analyses are helpful when studying the biological functions and potential clinical applications of modified nucleosides. In this regard, high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) offers significant advantages in terms of sensitivity, selectivity, and efficiency, and has been widely used to analyze DNA and RNA nucleosides/nucleotides and their analogues. Multiple MS detection patterns and quantification methods have been established to detect nucleosides in biological samples, including cultured cells, urine, blood, and tissue samples. However, the development of an accurate HPLC-MS/MS method faces several challenges. Firstly, the presence of a complex biological matrix that contains macromolecules, small molecules, and salts can interfere with analysis. Salts and co-eluting substances in the extraction solution often affect mass-spectrometric responses for target analytes. Secondly, various nucleosides are present in vastly different abundances, with contents varying by up to four orders of magnitude; hence, accurately quantifying multiple nucleosides in a single assay is challenging. Thirdly, <i>N</i>-glycosidic bonds are favorably cleaved in most nucleosides during MS to produce the same characteristic fragment ions, which are often accompanied by nucleobases. This tendency poses challenges for distinguishing structural isomers and mass-analogs of modified nucleosides by MS. Post-transcriptional chemical modifications include methylation, hydroxylation, sulfur/oxygen substitution, and side-chain additions. Developing a unified method for simultaneously screening modified nucleosides is difficult owing to biochemical diversity; consequently, there is a need for advanced HPLC-MS/MS method capable of accurately quantifying such nucleosides. This","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 1","pages":"3-12"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11686471/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Research advances in the transplacental transfer efficiencies of environmental pollutants].","authors":"Ke-Yu Yuan, Jun Xiong, Bi-Feng Yuan","doi":"10.3724/SP.J.1123.2024.07002","DOIUrl":"10.3724/SP.J.1123.2024.07002","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Industrialization has led to significant increases in the types and quantities of pollutants, with environmental pollutants widely present in various media, including the air, food, and everyday items. These pollutants can enter the human body via multiple pathways, including ingestion through food and absorption through the skin; this intrusion can disrupt the production, release, and circulation of hormones in the body, resulting in a range of illnesses that affect the reproductive, endocrine, and nervous systems. Consequently, these pollutants pose substantial risks to human health. In particular, fetuses are highly sensitive to environmental pollutants during critical stages of development, and exposure during periods of growth and development can result in more-obvious and severe health hazards that can lead to preterm birth, low birth weight, and fetal malformations. The placenta acts as a barrier between the mother and fetus, and selectively filters certain pollutants. While some pollutants remain in the maternal bloodstream, others cross the placental barrier into the fetal umbilical blood through passive diffusion, placental transport proteins, or endocytosis. The transplacental transfer efficiency (TTE) is the ratio of the level of the pollutant in the umbilical blood to that in the maternal blood, and is a valuable metric for evaluating the ability of a pollutant to breach the placental barrier. A higher TTE implies that a larger proportion of pollutants are transferred from the mother to the fetus, thereby amplifying the potential risks to the fetus. Mass spectrometry-based detection methods are extensively used in the chemical and environmental sciences because they are exceptionally sensitive and highly resolving. This analytical technique involves ionizing compounds within a sample and identifying them based on their distinct mass-to-charge ratios; it enables both qualitative and quantitative analyses of various environmental pollutants. Current methodologies for examining the TTE of a pollutant include in-vitro experiments, animal studies, epidemiologic studies, and model calculation; these approaches help to evaluate the transfer of pollutants from mother to fetus via the placenta. Analyzing the TTEs of different chemicals enables high-risk pollutants to be identified and provides an understanding of their abilities to cross the placenta. Research on the transplacental transfer of environmental pollutants has focused mainly on per- and polyfluoroalkyl substances (PFASs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs), with relatively few studies on the TTEs of other pollutants reported. Pollutant transfer through the placenta is a complex process that is influenced by factors that include the physical and chemical properties of the pollutant (e.g., molecular mass, solubility, and lipophilicity), maternal factors (e.g., maternal health and lifestyle, maternal ge","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 1","pages":"13-21"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11686480/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"[Determination of 12 halogenated organic pollutants in edible fish by ultra performance liquid chromatography-high resolution mass spectrometry combined with ultrasound-assisted extraction and gel permeation chromatography purification].","authors":"Yi-Zhe Zhu, Rui-Fen Zheng, Zi-Hao Fan, Ling Liu, Jing-Yao Ye, Kai Wang, Cai-Ming Tang","doi":"10.3724/SP.J.1123.2023.12028","DOIUrl":"10.3724/SP.J.1123.2023.12028","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Halogenated organic pollutants (HOPs) have attracted considerable attention owing to their persistence, bioaccumulation, and toxicity. The development of methods to detect HOPs in fish is challenging owing to the compositional complexity of fish matrices, which contain high levels of lipids and relatively low concentrations of HOPs. In addition, the lipophilicity of most HOPs renders their extraction difficult. Moreover, the simultaneous determination of multiple HOPs to achieve the high-throughput screening of these analytes is complex. In this study, a reliable and efficient pretreatment method based on ultrasound-assisted extraction, gel permeation chromatography purification, and ultra performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS) was developed for the determination of 12 HOPs in edible fish. The procedures of sample extraction and purification and LC-HRMS detection parameters were optimized to improve the performance of the method. Fresh fish samples were thoroughly rinsed with water, and non-edible parts, including the skin, bones, and phosphorus, were removed. The fish were weighed, cut into small pieces, and vacuum freeze-dried for 48 h. Subsequently, a freeze grinder was used to grind the dried fish into a fine powder. Exactly 2 g of the fish powder was weighed, fortified with isotope-labeled internal standards of the HOPs, and allowed to stand for 5 min. Methanol-acetonitrile (1∶1, v/v) was then added, followed by vortex mixing and ultrasonication. After centrifugation, the supernatant was transferred to a fresh tube. The extraction process was repeated twice and all extracts were combined. The extract was evaporated under a gentle nitrogen flow and redissolved in a mixture of ethyl acetate-cyclohexane (1∶1, v/v). The sample mixture was cleaned using gel permeation chromatography, and the eluate was collected and concentrated under a nitrogen flow. Sample residuals were reconstituted with water-methanol (1∶1, v/v) prior to instrumental analysis. Chromatographic separation was performed using an ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm). Water containing 2 mmol/L NH&lt;sub&gt;4&lt;/sub&gt;Ac and acetonitrile were used as the mobile phases, and an optimized gradient elution program was applied. Isotope dilution and an internal standard method were used to quantify the HOPs. An electrospray ionization source operated in negative mode was applied to ionize the HOPs, and a full scan together with data-dependent acquisition (DDA) was applied for HRMS. Excellent linearities (&lt;i&gt;R&lt;/i&gt;&lt;sup&gt;2&lt;/sup&gt;&gt;0.99) were obtained for all HOPs in the quantification range of 1.0-1000.0 ng/mL. The limits of quantification were 0.5 ng/g. The analytical method was validated using pooled fish samples fortified with HOP standards (4, 40, and 400 ng/g). The recoveries of the HOPs were in the range of 67.6%-133.8%, and the corresponding RSDs were 0.5%-15.6%. A total of 27 commercially available fish samples were analyzed using th","PeriodicalId":101336,"journal":{"name":"Se pu = Chinese journal of chromatography","volume":"43 1","pages":"68-77"},"PeriodicalIF":0.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11686473/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142901577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}