Analytical Methods最新文献

{"title":"Deamidation analysis of therapeutic drugs using matrix-assisted laser desorption ionization mass spectrometry and a novel algorithm QuanDA.","authors":"Han Zhang, Yinran Xiong, Xiaonan Shi, Lijia Zhu, Qiong Wu, Ting Wu, Yiping Du","doi":"10.1039/d4ay01595a","DOIUrl":"https://doi.org/10.1039/d4ay01595a","url":null,"abstract":"<p><p>A robust deamidation quantification method, called QuanDA, was developed to quantify the spontaneous nonenzymatic deamidation of peptides based on the isotopic distribution change of peptides in matrix-assisted laser desorption ionization (MALDI) mass spectra and non-negative least squares calculation. The predictive model of QuanDA using theoretical spectra of pure un-deamidated and deamidated peptides for a series of simulated partial deamidated peptides is satisfying, with a coefficient of determination (<i>R</i>²) and root mean squared error (RMSE) of 0.9914 and 0.03356, respectively. It was applicable in cases where there is a lack of reference standards of un-deamidated and deamidated peptides. The only requirements were the chemical formulae of un-deamidated and deamidated peptides for isotopic pattern calculation. QuanDA provided a rapid, low-cost and easily accessible method for deamidation analysis in therapeutic drugs.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A dual-emission carbon dots/gold nanoclusters fluorescent probe for ratiometric and colorimetric detection of Pb²⁺ and Hg².","authors":"Hongxin Cai, Yixin Shao, Lingling Yan, Hang Yu, Qiang Hu, Yongqiang Wang, Xiude Tu","doi":"10.1039/d4ay01638f","DOIUrl":"https://doi.org/10.1039/d4ay01638f","url":null,"abstract":"<p><p>A novel fluorescent probe, carbon dots/gold nanoclusters (CDs/AuNCs), was prepared for ratiometric and colorimetric detection of Pb²⁺ and Hg²⁺ simultaneously. The as-prepared probe exhibited two distinct emission peaks at 445 nm and 610 nm. During the detection process, Pb²⁺ could quench blue fluorescence due to the formation of the CDs-Pb²⁺ complex and does not affect orange fluorescence. Conversely, Hg²⁺ could quench the orange fluorescence greatly due to the Hg²⁺-Au⁺ metallophilic interaction and keep blue fluorescence unaffected. Accordingly, ratiometric fluorescence sensing approaches of Pb²⁺ and Hg²⁺ are achieved and dramatic color changes from pink to orange/blue can be observed under UV illumination upon the addition of Pb²⁺/Hg²⁺. Furthermore, good linear relationships between the fluorescence intensity ratio (<i>I</i>₆₁₀/<i>I</i>₄₄₅) and Pb²⁺/Hg²⁺ concentration were demonstrated in ranges of 0-130 nM for Pb²⁺ and 0 to 280 nM for Hg²⁺, with detection limits of 6.5 nM for Pb²⁺ and 3.7 nM for Hg²⁺, respectively. The probe showed excellent selectivity and the mutual interference problem of coexistence of Pb²⁺ and Hg²⁺ could be effectively solved by introducing masking agents. In addition, the application of CDs/AuNCs proved successful in detecting Pb²⁺ and Hg²⁺ in actual water samples, yielding satisfactory recovery rates. These results indicated that the probe provides a new approach for visualizing and semi-quantitatively detecting Pb²⁺ and Hg²⁺, making it highly promising for monitoring environmental water samples.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid low-level nitrate determination by UV spectroscopy in the presence of competing ions.","authors":"S E Mackay, D S Eldridge, F Malherbe","doi":"10.1039/d4ay01641f","DOIUrl":"https://doi.org/10.1039/d4ay01641f","url":null,"abstract":"<p><p>The presence of excessive nitrate in environmental and drinking water even at low levels can pose both environmental and health hazards. Because of this, various methods for its removal have been investigated. Essential to conducting such research is a method to reliably quantify nitrate in relevant matrices. However, current approaches have drawbacks related to cost, analysis time or health hazards. This study evaluates a UV spectroscopy-based method for nitrate determination, suitable for quantifying low nitrate concentrations in the presence of bicarbonate, sulfate, chloride and phosphate. The limits of detection and quantification were found to be 0.003 ppm N and 0.0077 ppm N respectively, lower than that observed in the ion chromatography method it was compared to. Additionally, a calibration curve created with 11 standards ranging from 0 to 2.5 ppm N demonstrated an exceptionally strong correlation, with an <i>R</i>² value greater than 0.9999. This method is developed with a focus on accessibility and speed, minimising hazards and waste generation for reduced environmental footprint. The effects of contaminants introduced through the use of commercial laboratory consumables are also discussed.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EigenRF: an improved metabolomics normalization method with scores for reproducibility evaluation on importance rankings of differential metabolites.","authors":"Chencheng Tang, Dongfang Huang, Xudong Xing, Hua Yang","doi":"10.1039/d4ay01569j","DOIUrl":"https://doi.org/10.1039/d4ay01569j","url":null,"abstract":"<p><p>Screening differential metabolites is of great significance in biomarker discovery in metabolomics research. However, it is susceptible to unwanted variations introduced during experiments. Previous normalization methods have improved the accuracy of inter-group classification by eliminating systematic errors. Nonetheless, the classification ability of differential metabolites obtained through these methods still requires further enhancement, and the reproducibility evaluation on importance rankings of differential metabolites is often disregarded. The EigenRF algorithm was developed as an improvement over the previous metabolomics normalization method referred to as EigenMS, which aims to normalize metabolomics data. Furthermore, scoring metrics, including the local consistency (LC) and overall difference (OD) scores, were introduced to evaluate the reproducibility of importance rankings of differential metabolites from a dual perspective. After conducting validation on three publicly accessible datasets, the EigenRF method has demonstrated enhanced classification ability of differential metabolites as well as improved reproducibility. In summary, EigenRF enhances the reliability of differential metabolites in metabolomics research, benefiting the further exploration of molecular mechanisms underlying biological alterations in complex matrices. The EigenRF algorithm was implemented in an R package: https://www.github.com/YangHuaLab/EigenRF.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A high-performance ionic liquid-based microextraction (ILBME) method for the trace determination of paroxetine as a pharmaceutical pollutant in environmental and biological samples.","authors":"Mehdi Hosseini","doi":"10.1039/d4ay01668h","DOIUrl":"https://doi.org/10.1039/d4ay01668h","url":null,"abstract":"<p><p>A high-performance ionic liquid-based microextraction technique utilizing a task-specific imidazolium-based ionic liquid was employed for the analysis of paroxetine as a pharmaceutical pollutant at trace levels in some real environmental and biological samples. An ionic liquid, 3-(2-hydroxy-4-(isopropylamino)butyl)-1-methylimidazolium chloride, abbreviated to [Hibmim][Cl], was synthesized with a yield of 90.4%. Its physical properties were determined and characterized using FTIR, HNMR, CNMR, and CHNO techniques. The ionic liquid was then used for preconcentration prior to the determination of paroxetine in water and urine samples. Specifically, the ionic liquid served as both the extractor and the extracting phase, demonstrating high efficiency in extracting paroxetine from real samples. Density functional theory (DFT) studies, as well as UV-Vis and FTIR analyses indicated that the ionic liquid could successfully form a chelate with paroxetine <i>via</i> hydrogen bonds. To confirm the method efficacy for analyzing real samples, the figures of merit and parameters affecting the microextraction procedure were assessed and optimized. Under optimal conditions, the limit of detection, limit of quantification, linear dynamic range, intra-day and inter-day relative standard deviations, preconcentration factor, and enhancement/enrichment factor were determined to be 0.42 μg L^-1, 1.41 μg L^-1, 5.0-60.0 μg L^-1, 2.58%, 3.83%, 197.3, and 193.3, respectively. The maximum yield of paroxetine extraction under optimal conditions was 98.8%. Finally, to evaluate the method validity, a standard addition procedure was used, yielding satisfactory recovery values ranging from 98.7% to 101.2%.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of severe acute respiratory syndrome coronavirus 2 in bioaerosols using digital droplet polymerase chain reaction and loop-mediated isothermal amplification.","authors":"Xinyu Zhang, Yuhong Guan, Song Li, Yan Deng, Yanqi Wu, Hui Chen","doi":"10.1039/d4ay01783h","DOIUrl":"https://doi.org/10.1039/d4ay01783h","url":null,"abstract":"<p><p>In the present study, we simulated human passive breathing, sampled severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) bioaerosols, and compared the detection ability of quantitative polymerase chain reaction (qPCR), digital droplet polymerase chain reaction (ddPCR), and loop-mediated isothermal amplification (LAMP). The specificity of the primer set for the LAMP-based detection of SARS-CoV-2 was evaluated, and its sensitivity using the detection threshold in the amplification curve plots was determined. Next, we used an aerosol collection environment and collected solutions containing predetermined concentrations of plasmid containing SARS-CoV-2 N gene, which were dispersed into the environment, using a cyclone sampler. Finally, we compared the ability of qPCR, ddPCR, and LAMP in detecting SARS-CoV-2 in aerosols and stock solutions. After sampling, qPCR, LAMP and ddPCR can amplify the micro viral samples exponentially. By comparing the three assays, it was judged from the results that qPCR had a slightly higher detection limit, detecting 10² copies per μL, and therefore could not be used as a test for trace samples. qPCR, LAMP, and ddPCR were able to detect aerosol samples of 10¹ copies per μL. LAMP was able to qualitatively detect the samples, and ddPCR was able to quantitatively detect samples of this order of magnitude. There were 23.2 that could be used as a quantitative assay. This method can be used in public places or hospitals with limited air circulation to detect aerosol-borne viruses in trace quantities and to provide a rapid early warning.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142666643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the performance of 3D printed (spectro)photometers based on multi-channel color sensors for colorimetric determinations.","authors":"Caio C S Machado, Alegre N S Cadeado, Yugo S N da Mota, João F S Petruci, Sidnei G Silva","doi":"10.1039/d4ay01831a","DOIUrl":"10.1039/d4ay01831a","url":null,"abstract":"<p><p>Portable and affordable (spectro)photometers based on digital color sensors are gaining significance in analytical chemistry due to their compact design, cost-effectiveness and integration capabilities. Despite their inherent straight-forward operation, various digital light sensors with distinct performance and optical characteristics are available on the market. For instance, AS7341 and AS7262 are multi-channel color sensors that covers eight and six spectra regions, respectively, while TCS34725 operates using three channels (red, green, and blue). In this study, the analytical performance of 3D printed, reflectance-based (spectro)photometers employing different digital color sensors was evaluated. Spectra resolution, signal gain and LED current were systematically evaluated to ensure the best performance for each sensor. The sensors' analytical performance was obtained by quantifying different dyes in aqueous solutions and sunset yellow in beverages as a proof-of-concept. All three sensors presented sub-millimolar detection with excellent linear coefficient (<i>r</i>² > 0,99) and sensitivity comparable to a conventional spectrophotometer. In the quantification of sunset yellow (<i>λ</i>_max = 480 nm) in the presence of tartrazine (<i>λ</i>_max = 430 nm), the AS sensors showed enhanced sensitivity and linearity, minimizing the spectral overlapping. Their versatility and cost-effectiveness make them ideal for real-time, portable applications. Furthermore, their compatibility with microcontrollers and capability for wireless data transmission enhance their utility across diverse analytical environments.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Xylan-based near-infrared fluorescent probes for monitoring viscosity abnormalities in living cells and zebrafish.","authors":"Shen Li, Wenchan Dong, HongKun Yang, Pengfei Sun, Jinlan Luo, Fangong Kong, Keyin Liu","doi":"10.1039/d4ay01860e","DOIUrl":"https://doi.org/10.1039/d4ay01860e","url":null,"abstract":"<p><p>Viscosity is a crucial indicator of the flow state of proteins, lipids, and polysaccharides in the cell microenvironment and plays a vital role in maintaining normal cellular activities. Abnormal viscosity in any part of the cell constituents can lead to various diseases in the organism. For instance, abnormal mitochondrial viscosity can lead to diseases, such as diabetes and Parkinson's disease. Therefore, real-time monitoring of changes in mitochondrial viscosity in both pathological and physiological environments is relevant. This study describes a water-soluble xylan-based near-infrared fluorescence probe that can detect changes in cellular viscosity. The designed mitochondria-targeting near-infrared fluorophores were introduced into modified xylan to form a viscosity-sensing fluorescent probe (NI-XylV). The fluorescence intensity of NI-XylV at 590 and 670 nm gradually increases with an increase in viscosity caused by environmental changes, enabling the sensitive detection of viscosity changes in mitochondria within living cells. NI-XylV exhibits good photostability, biocompatibility, excellent mitochondrial targeting, and broad application prospects as a bio-based fluorescence probe.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Embedded microdrops configuration for diffusion-based colorimetric reactions: a novel approach for thiol determination by the Ellman reaction.","authors":"Archana Jain, Manju Gupta, Krishna K Verma","doi":"10.1039/d4ay01454e","DOIUrl":"https://doi.org/10.1039/d4ay01454e","url":null,"abstract":"<p><p>A new variant of micro-colorimetry, called Extractive Reactions in Embedded Drops (EXRED), utilizes an aqueous drop of a reagent (2 μL) surrounded by a liquid film of isooctane : octanol (1 : 1, v/v; 2.5 μL) and supported by a microsyringe placed immersed into the aqueous sample solution. This configuration conducted all events of the reaction occurring in a single step, <i>viz.</i>, microextraction, matrix cleanup and preconcentration of the analyte by diffusion into the reagent drop, and the specific colorimetric reaction. The method has been verified for the determination of thiols by the Ellman reagent (5,5'-dithio-bis(2-nitrobenzoic acid), disodium salt). The embedded drops were constructed by sequentially withdrawing measured aliquots of the Ellman reagent and the organic solvent into a microsyringe and mounting the needle tip with a polytetrafluoroethylene (PTFE) sleeve terminating into a microfunnel. Then, while protruding the sleeve tip into the acidified aqueous thiol sample, the syringe plunger was slowly pressed to form a composite reagent drop. The embedded drop configuration allowed the diffusion of unionic thiols through the organic solvent film from the acidified donor phase (the sample) into the acceptor Ellman reagent drop. The intense yellow colour of 2-nitro-5-thiobenzoate formed was measured by fiber optic CCD array NanoDrop micro-spectrophotometry. The thiol migration rate was a function of the molecular geometry of individual thiols, attaining molar absorptivities in the range from 3.73 × 10⁴ to 1.33 × 10⁵ L M^-1 cm^-1 that were 3 to 10 times the reported value of the classical Ellman reaction, establishing the calibration range of 5-700 μM of thiol. In the second method, ionic and unionic thiols were prereacted with the Ellman reagent, and the reaction product 2-nitro-5-thiobenzoate, after acidification, was made to diffuse through the solvent film into an acceptor drop of pH 8 phosphate buffer. Here, the average molar absorptivity obtained (3.85 × 10⁵ L M^-1 cm^-1) was 28 times the value of the classical reaction, producing the calibration range of 2-60 μM of thiol. The averaged LOD/LOQ values for the two methods were 0.048/0.16 μM. The response surface methodology-optimized parameters were (a) Ellman reagent (25 mM), (b) extraction time (17 min) and (c) sodium sulphate (500 mg). The EXRED methods obeyed the green analytical chemistry criteria, <i>viz.</i>, AGREE (0.65), AGREEprep (0.83), ComplexGAPI, BAGI (65.0) and metric of sustainability (7.79).</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electrochemical sensors based on composites of porous Fe₃O₄/C and carbon black for sensitive and rapid detection of propofol.","authors":"Shouhui Chen, Dan Zhou, Qinghao Xiong, Yinan Yang, Mingyang Zhang, Shoulin Chen","doi":"10.1039/d4ay01280a","DOIUrl":"https://doi.org/10.1039/d4ay01280a","url":null,"abstract":"<p><p>Nowadays, many people are turning to medications that can help them stay calm during surgeries and their daily lives. As an anesthetic that reduces the excitability of nerve cells, propofol can achieve sedation with the advantages of fast onset and short half-life. The development of propofol sensors has tremendous application potential because they can help healthcare professionals dynamically regulate the concentration of propofol in the blood, not only to achieve the painless surgeries that patients want, to maintain the sedation that surgeons desire, but also to prevent the respiratory failure that may occur with a patient's daily sleep aids. In this paper, we prepared Fe₃O₄/C/CB nanocomposites by doping carbon black on the surface of the pyrolyzed product of MIL-88B. The nanocomposites-modified glassy carbon electrodes were used to detect propofol in phosphate buffer solution. The porous nanocomposites with high electrical conductivity promoted the charge transfer on the electrode surface, improving the performance of the modified electrodes. After optimization, the linear range, the detection limit, and the sensitivity for propofol were 5.0-205 μM, 0.102 μM, and 2.850 μA cm^-2 μM^-1, respectively. The electrochemical sensing of propofol in a medical propofol emulsion injection and in normal human serum showed that the method was rapid and repeatable.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}