Analytical Methods最新文献

{"title":"Rapid analysis of <i>N</i>-nitrosamines in urine using ultra high-pressure liquid chromatography-mass spectrometry.","authors":"S Shinde, K D Croft, J M Hodgson, C P Bondonno","doi":"10.1039/d4ay01870b","DOIUrl":"https://doi.org/10.1039/d4ay01870b","url":null,"abstract":"<p><p><i>N</i>-Nitrosamines, carcinogenic compounds present in dietary and environmental sources and formed endogenously, are believed to be linked with the presence of nitrate and nitrite, both within dietary sources and after intake. To fully evaluate this potential threat to human health, an accurate analytical method to measure <i>N</i>-nitrosamines in biological matrices is necessary. We report a simple, fast, selective mass spectrometry method to detect <i>N</i>-nitrosamines in human urine. Analysis of seven <i>N</i>-nitrosamines, <i>N</i>-nitrosodimethylamine (NDMA), <i>N</i>-nitrosomethylethylamine (NMEA), <i>N</i>-nitrosodiethylamine (NDEA), <i>N</i>-nitrosopiperdine (NPIP), <i>N</i>-nitrosopyrrolidine (NPYR), <i>N</i>-nitrosodi-<i>N</i>-propylamine (NDPA) and <i>N</i>-nitrosodi-<i>N</i>-butylamine (NDBA) in urine was quantitated using Ultra High-Pressure Liquid Chromatography-tandem Mass spectrometry (UHPLC-MS/MS). A Sorbent supported Liquid Extraction (SLE) method was employed to extract <i>N</i>-nitrosamines from 24 hour collected human urine samples. The percent recovery varied between 74.3 to 110 and the limit of detection and limit of quantification ranged from 0.1 to 0.85 ng mL^-1 and 0.22 to 2.06 ng mL^-1 respectively. Precision for inter-day and intra-day assay yielded a % coefficient of variation between 4-10% for all measured compounds in urine. Linear regression analysis of calibration curves for <i>N</i>-nitrosamines measured in urine in the concentration range 0.4-12.8 ng mL^-1 gave correlation coefficients, <i>R</i>² 0.9874-0.9962. Urinary excretion of <i>N</i>-nitrosamines measured in ten healthy subjects resulted in detection of most of the <i>N</i>-nitrosamines including NDMA, NDEA, NPYR, NDPA and NDBA by this method.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142520288","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":"Combining method validation data with additional information for measurement uncertainty evaluation - determination of melatonin content in tea.","authors":"Lucía Gutiérrez-Fernández, Cristina M Oliveira, Ana M Díez-Pascual, María Paz San Andrés, Ricardo J N Bettencourt da Silva","doi":"10.1039/d4ay01468e","DOIUrl":"https://doi.org/10.1039/d4ay01468e","url":null,"abstract":"<p><p>The evaluation of measurement uncertainty involves combining available experimental data with additional knowledge on the impact of sources of uncertainty on the measured value to quantify combined uncertainty. This uncertainty should express the impact of relevant random and systematic effects on the measured value to allow an objective interpretation of the performed quantification. This research discusses how to assess and account for the impact on measurement uncertainty evaluation of uncontrolled high temperature of sample preparation and of supporting experimental validation data on a single calibration of the instrumental method of analysis used. After the detailed inspection of the measurand and measurement process, the various uncertainty components were quantified from experimental data and/or additional information. This research illustrates that experimental limitations can be overcome by a detailed and quantitative understanding of the measurement process. Melatonin content in tea was quantified between 3.7 g kg^-1 and 196 g kg^-1 with a relative expanded uncertainty between 28% and 40%, lower than the target or maximum admissible relative expanded uncertainty of 40%. The use of HPLC-FD calibration several days before sample analysis is the major uncertainty component responsible for up to 82.7% of the measurement uncertainty.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491218","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 portable fluorescence sensing system for timely onsite perfluorooctane sulfonate detection based on an aggregate induced emission fluorescence sensor.","authors":"Bin Wang, Yaning Yu, Rongxu Zhao, Liang Yan, Tingfeng Tan, Peiyao Chen, Chao Ma","doi":"10.1039/d4ay01698j","DOIUrl":"https://doi.org/10.1039/d4ay01698j","url":null,"abstract":"<p><p>Perfluorooctane sulfonate (PFOS), a ubiquitous persistent organic pollutant, has aroused growing concern due to its adverse effects on human health. Timely onsite monitoring of PFOS in heavily contaminated areas is crucial for effective pollution management and prevention of its spread. However, relevant PFOS detection methods have rarely been reported. Herein, we developed a fluorescence sensing system capable of achieving timely onsite detection of PFOS under outdoor conditions. First, aggregate induced emission (AIE) fluorescence sensors, TPE-PAs, were synthesized. The optimized sensor could selectively interact with PFOS through electrostatic attraction and hydrogen bonding and exhibited prominent fluorescence enhancement after treating with PFOS. There was a good linear relationship between the fluorescence enhancement and PFOS concentration in the range of 0.05-30 ppm, and the limit of detection was measured to be 0.047 ppm. In addition, owing to the AIE fluorescence mechanism and high concentration of TPE-PAs in the sensing medium, the sensor demonstrated excellent anti-interference performance. Second, we developed a portable fluorometer, by modifying the power supply and sample cell of a tiny fluorometer, and further integrated this modified fluorometer, the prepared fluorescence sensor, standard PFOS solutions and other consumables into a portable test system. This test system showed good detection accuracy and reliability and successfully achieved timely onsite PFOS detection in real water samples.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491216","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":"MnO/TiO₂/C/N-CNTs derived from Mn-doped Ti MOFs for simultaneous detection of catechol and hydroquinone.","authors":"Wenjing Liu, Sumin Xu, Jinjin Zhang, Jianying Qu","doi":"10.1039/d4ay01217h","DOIUrl":"https://doi.org/10.1039/d4ay01217h","url":null,"abstract":"<p><p>Mn-doped Ti-based MOFs (MnTi MOFs) were synthesized by a solvothermal method, and calcined at high temperature after being mixed with pre-prepared PPy nanotubes to give MnO/TiO₂/C/N-CNTs composites. The composites were studied by SEM, XRD, XPS and FTIR. Based on these composites, a new electrochemical sensor was prepared, which has good electrocatalytic ability for the redox of catechol (CC) and hydroquinone (HQ), and can detect CC and HQ simultaneously. The results showed that the oxidation peak current of CC and HQ increased linearly in the concentration range of 0.50-120.00 μM. The detection limits were 0.033 μM and 0.019 μM, respectively. The constructed sensor has been successfully used for the simultaneous detection of CC and HQ in lake water and tap water, and has a good recovery rate.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491222","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":"Micro-fluidic covalent immobilization of multi-gradient RGD peptides on a gelatin surface for studying endothelial cell migration.","authors":"Yunong Yang, Yanxia Wang, Yongjiang Li, Xuqu Hu, Changgui Tong, Chundong Xue, Kairong Qin","doi":"10.1039/d4ay01409j","DOIUrl":"https://doi.org/10.1039/d4ay01409j","url":null,"abstract":"<p><p>Collective endothelial migration is a hallmark of wound healing, which is regulated by spatial concentration gradients of extracellular biochemical factors. Arginine-glycine-aspartate (RGD) peptides play a vital role in regulating cell migration through specific binding to integrins. In this study, a micro-fluidic technology combined with a photopolymerization technique is developed to create gelatin methacryloyl (GelMA)-based substrates with various concentration gradients of RGD peptides. The capability of generating linear and nonlinear RGD concentration gradients was quantitatively verified through numerical simulation and immunohistochemical quantitative experiments. The results of the concentration gradients show a strong concurrence between the immunohistochemical quantification experiments and numerical simulations. Furthermore, endothelial migration experiments were conducted with various concentration gradients of RGD peptides. We have observed that endothelial cells on the surface of gels with a linear concentration gradient exhibit a larger cell area, a longer cell perimeter, and more stress fiber density. Furthermore, the cells demonstrate directional alignment and migration towards regions with a higher RGD concentration. High concentration gradients significantly enhance endothelial cell migration, consistent with observations on surfaces of gels with nonlinear concentration gradients. In brief, we proposed a simple and effective micro-fluidic photopolymerization technique capable of generating diverse concentration gradients of RGD and probing their effects on cell migration. The results suggest that regulating the RGD peptide concentration gradients can alter the migration of endothelial cells, showing potential for promoting wound healing.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491221","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":"Development and validation of diffusive gradients in thin-films for <i>in situ</i> monitoring of ionic liquids in waters.","authors":"Si-Si Liu, Shi-Bao Chen, Yu-Bo Yue, Xiao-Hao Li, Chi Zhang, Guang-Guo Ying, Chang-Er Chen","doi":"10.1039/d4ay01730g","DOIUrl":"https://doi.org/10.1039/d4ay01730g","url":null,"abstract":"<p><p>Due to their wide applications, occurrence and \"PFAS-like\" environmental behaviors, ionic liquids (ILs) represent a new challenge for the environmental monitoring community, who require robust analytical methods that can determine accurately and efficiently their environmentally relevant concentrations. A new passive sampling method based on the diffusive gradients in thin films (DGT) technique was developed for the measurement of imidazole-based ILs in waters using a mixed-mode cation exchange (MCX) resin as the adsorbent. The selected binding gel had a high binding capacity (>170 μg per disc) for ILs. Diffusion coefficients measured using a diffusion cell correlated well with alkyl chain lengths (<i>r</i>² = 0.95) and retention times (<i>r</i>² = 0.88), providing a simple and rapid prediction approach for other ILs. The assembled MCX-DGT sampler exhibited a linear accumulation for at least 120 h. MCX-DGT also showed good performance under typical freshwater conditions (pH 5-8, ionic strength 0.001-0.01 M, and humic acid 0-5 mg L^-1), while still being problematic for aquatic conditions with higher ionic strength (>0.1 M) or DOM (>10 mg L^-1). Laboratory deployment (for up to 3 days) in spiked natural freshwater (SNW) resulted in linear mass uptakes for the short-chain ILs (C2-C8), and their DGT-measured concentrations agreed well with solution concentrations. However, MCX-DGT significantly overestimated the concentrations of the long-chain ILs (C10-C12) when deployed in SNW for one day or more, which is attributed to the strong competitive adsorption of the long-chain ILs by natural organic matter. <i>In situ</i> field evaluation along with grab sampling found no target ILs in a wastewater treatment plant and its receiving river, implying that these new chemicals might not be widely used in South China now. This is the first report on the DGT technique for ILs and might provide an effective tool for monitoring short chain length ILs in the aquatic environment in the near future.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491219","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":"Real-time optical detection of mercury contamination in drinking water using an amphiphilic recognition probe at liquid crystal/aqueous interfaces.","authors":"Satyabratt Pandey, Madeeha Rashid, Vishal Singh, Garima Singh, Chandan Bhai Patel, Rohit Verma, Dharm Dev, Ranjan Kumar Singh, Sachin Kumar Singh","doi":"10.1039/d4ay01482k","DOIUrl":"https://doi.org/10.1039/d4ay01482k","url":null,"abstract":"<p><p>Mercury contamination is a global environmental issue due to its toxicity and persistence in ecosystems. It poses a particular risk in aquatic systems, where it bioaccumulates and biomagnifies, leading to serious health impacts on humans. Therefore, effective detection technologies for mercuric ions in natural water resources are highly desirable. However, most existing detection methods are time-consuming, require complicated sample pre-treatment, and rely on expensive equipment, which hinders their widespread use in real-time detection. Here, we present a convenient, rapid, portable, user-friendly, and cost-effective sensing system for detecting Hg²⁺ ion contamination in water. This system utilizes a highly selective, amphiphilic, and structurally simple molecular probe, <i>N</i>-dodecylamine-di-thiocarbamate (DDC). DDC molecules align at the interface between the liquid crystal (LC) and water, inducing a homeotropic LC orientation. In water samples contaminated with Hg²⁺, a bright optical texture is observed, indicating the alignment of the 5CB LC in a planar manner at the LC/aqueous boundary. The minimum detectable concentration (LOD) for Hg²⁺ ions is 5.0 μM in distilled water, with a broad detection range from 5.0 μM to 2 mM. The sensor selectively detects Hg²⁺ ions over other common interfering metal ions, including Pb²⁺, Co²⁺, Ni²⁺, Cu²⁺, Cd²⁺, Zn²⁺, Cr²⁺, Mg²⁺, Na⁺, K⁺, and Ca²⁺. Boolean logic gates, bar graphs, and truth tables are employed to explain the selectivity of this liquid crystal-based sensor. This work demonstrates the significant potential of the sensor for monitoring mercuric ions in natural water resources, offering a promising strategy for controlling mercury pollution.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491224","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":"An indolium ion-based colorimetric sensor for naked-eye detection of cyanide and ammonia: on-site detection technique for cyanide in natural sources and day-to-day monitoring of food spoilage.","authors":"Jhorna Borah, Arati Chetry, Arobinda Kakoti, Prithiviraj Khakhlary","doi":"10.1039/d4ay01516a","DOIUrl":"https://doi.org/10.1039/d4ay01516a","url":null,"abstract":"<p><p>Herein, we developed an easy-to-synthesize, simple colorimetric probe and demonstrated its potential for the detection of anions and amines. The probe was capable of detecting CN^- selectively among other anions and could detect the presence of all tested amines. It exhibited obvious colour and spectroscopic changes in the presence of the said analytes. The probe was highly sensitive to CN^- ions, which enabled the detection of trace amounts of the aforementioned anion. The detection limit for CN^- was found to be 3.98 × 10^-8 M, which is below most of the LOD values reported thus far. The sensing was further extended to the solid state by effectively immobilizing the probe in a hydrogel matrix. Moreover, upon exposure to ammonia vapour, noticeable colour changes were observed in a probe-coated paper chip within few minutes. Moreover, the practical application of the probe was demonstrated for both CN^- and amines. The probe can serve as a promising alternative for detection of CN^- content in food and monitoring of biogenic amines and food freshness.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142491217","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":"Simultaneous analysis of depurinated nucleic acid stem-loop and free adenine for ricin toxicity assay by hydrophilic interaction liquid chromatography-high-resolution mass spectrometry (HILIC-HRMS).","authors":"Hajime Miyaguchi","doi":"10.1039/d4ay01203h","DOIUrl":"https://doi.org/10.1039/d4ay01203h","url":null,"abstract":"<p><p>A simple, accurate method for measuring ricin activity was developed by detecting depurinated nucleic acid stem-loops and adenine using a commercially available hydrophilic interaction liquid chromatography (HILIC) column and a quadrupole-Orbitrap tandem mass spectrometer. Ricin in beverages was isolated using magnetic beads conjugated with ricin B-chain antibodies, and then incubated with a 14 mer RNA or a 12 mer RNA/DNA chimera, in which adenosine at the depurination site of RNA was replaced by deoxyadenosine. The adenine and depurinated nucleic acids were separated by HILIC and both analytes were detected by high-resolution mass spectrometry. The depurinated RNA was detectable at concentrations as low as 100 pM (6.5 μg mL^-1) in orange juice and coffee, and 10 pM (0.65 μg mL^-1) in milk and sake after incubation with the RNA substrate for 4 h. Free adenine was detectable at 10 pM in all matrices, although free adenine was also detected in all blanks and could not be distinguished from the coffee and orange juice blanks at 10 pM. When using the chimera as the substrate, the depurinated chimera and adenine were detected up to concentrations of 10 pM as larger peaks. However, since the depurinated chimera and adenine were also detected in blanks, careful judgment was needed to determine whether they were active. Following the assay, the captured ricin could be analyzed by enzymatic digestion and nano liquid chromatography-high-resolution mass spectrometry. The ricin A chain-specific T7A peptide was detectable at 10 pM for sake and at 100 pM for milk, orange juice, and coffee. Using the present method, a toxicity assay and qualitative analysis of ricin were feasible with a 0.2 mL beverage sample.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453557","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":"Droplet-based fluorescence anisotropy insulin immunoassay.","authors":"Damilola I Adeoye, Rafael A Masitas, James Thornham, Xiangyue Meng, Daniel J Steyer, Michael G Roper","doi":"10.1039/d4ay01511h","DOIUrl":"10.1039/d4ay01511h","url":null,"abstract":"<p><p>Over the last several decades, multiple microfluidic platforms have been used for measurement of hormone secretion from islets of Langerhans. Most have used continuous flow systems where mixing of hormones with assay reagents is governed by diffusion, leading to long mixing times, especially for biomolecules like peptides and proteins which have large diffusion coefficients. Consequently, dispersion of rapidly changing signals can occur, reducing temporal resolution. Droplet microfluidic systems can be used to capture reagents into individual reactors, limiting dispersion and improving temporal resolution. In this study, we integrated a fluorescence anisotropy (FA) immunoassay (IA) for insulin into a droplet microfluidic system. Insulin IA reagents were mixed online with insulin and captured quickly into droplets prior to passing through a 200 mm incubation channel. Double etching of the glass device was used to increase the depth of the incubation channel compared to the IA channels to maintain proper flow of reagents. The droplet system produced highly precise FA results with relative standard deviations < 2% at all insulin concentrations tested, whereas the absolute fluorescence intensity precisions ranged between 5 and 6%. A limit of detection of 3 nM for insulin was obtained, similar to those found in conventional flow systems. The advantage of the system was in the increased temporal resolution using the droplet system where a 9.8 ± 2.6 s response time was obtained, faster than previously reported continuous flow systems. The improved temporal resolution aligns with continued efforts to resolve rapid signaling events in pancreatic islet biology.</p>","PeriodicalId":64,"journal":{"name":"Analytical Methods","volume":null,"pages":null},"PeriodicalIF":2.7,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11492383/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142453548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}