{"title":"Effect of ammonium fluoride as a mobile phase additive on quantitativity of fatty acids in electrospray ionization–liquid chromatography–tandem mass spectrometry","authors":"Kohei Kawabata, Haruka Muraoka, Yuya Ohtsuki, Soo Takasu, Yukihiro Esaka, Akira Tokumura, Hiroyuki Nishi","doi":"10.1007/s44211-025-00832-7","DOIUrl":"10.1007/s44211-025-00832-7","url":null,"abstract":"<div><p>Fatty acids (FAs) are essential molecules in biological systems and have crucial roles for fundamental components of cellular membranes, energy stores and mediators for cellular functions. The growing importance of FAs has also paid attention to analytical methods for the determination of FA contents in various samples accurately. Liquid chromatography tandem mass spectrometry (LC–MS/MS) analysis is a powerful tool due to less time for sample preparation and analysis. This analytical approach enables to quantify levels of FA and other lipid classes in various samples simultaneously without derivatization. In the present study, the effects of ammonium salts on the sensitivity of FAs in LC–MS/MS analysis were evaluated. First, authors performed the comparison of FA analysis with different mobile phases, which contain ammonium formate, ammonium fluoride, ammonium acetate or ammonium carbonate. Interestingly, the mobile phase containing ammonium fluoride enhanced the sensitivity of targeted FA species more than other ammonium salts. Second, the difference of quantativity of FA species was examined. It was indicated that both carbon chain length and the number of double bonds affect ionization of FA species. Finally, the method of FA analysis based on ammonium fluoride was applied to FA profiling of lotus root. It is indicated that mobile phase containing ammonium fluoride enabled to evaluate FA contents with highly sensitivity in LC–MS/MS analysis.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1681 - 1688"},"PeriodicalIF":2.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144870979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Iveta S Turomsha, Maxim Y Gvozdev, Natalia V Loginova
{"title":"Sterically hindered phenolic azomethine dyes derived from aliphatic amines: solvatochromism, DFT studies and antioxidant activity.","authors":"Iveta S Turomsha, Maxim Y Gvozdev, Natalia V Loginova","doi":"10.1007/s44211-025-00837-2","DOIUrl":"https://doi.org/10.1007/s44211-025-00837-2","url":null,"abstract":"<p><p>Displaying versatile biological activity, Schiff bases are known to possess prominent optical, thermal, and metal coordination properties, rendering them prospective for the design of dyes, photonic devices, ion sensors, molecular probes, etc. Furthermore, azomethine compounds bearing a phenolic moiety may exert antioxidant action. In this work, the antioxidant activity of the bis-substituted and mono-substituted phenolic azomethine dyes derived from 4,6-di-tert-butyl-2,3-dihydroxybenzaldehyde was determined in DPPH radical and ABTS cation radical scavenging assays, FRAP and CUPRAC metal reducing assays, and ferrous iron chelating activity assay. The effects of aliphatic amine substituents, steric factors, and the coordination behavior of the compounds on their antioxidant activity were studied. Experimental results of the antioxidant activity assays and plausible mechanisms of antioxidant action were elucidated with reference to the reaction parameters and global reactivity descriptors calculated for the DFT-optimized compound structures. The studied phenolic Schiff bases were characterized by spectroscopic and quantum chemical methods. Solvatochromic properties of the compounds were investigated in terms of the influence of solvent nature and the acidity and basicity of the medium on their catechol imine/quinone methide tautomerism.</p>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144854268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ikuo Ueta, Nan Jin, Tetsuo Kuwabara, Yoshihiro Saito
{"title":"Evaporation of volatile guest compounds incorporated into solid-state cyclodextrins.","authors":"Ikuo Ueta, Nan Jin, Tetsuo Kuwabara, Yoshihiro Saito","doi":"10.1007/s44211-025-00833-6","DOIUrl":"https://doi.org/10.1007/s44211-025-00833-6","url":null,"abstract":"<p><p>The evaporation of volatile naphthalene compounds incorporated into solid-state cyclodextrins (CDs) was quantitatively evaluated using a solid-phase extraction (SPE) device and high-performance liquid chromatography (HPLC). Initially, an aqueous CD solution was spiked on a quartz filter and dried. Then, solution of naphthalene compounds in acetone was spiked on the filter, resulting in the formation of guest-CD complexes on the filter. The filter was fixed in a filter holder, and the SPE device was connected to the filter holder. Subsequently, clean air was collected via the filter holder and the SPE device using a gas sampling pump. During air sampling, naphthalene compounds evaporated from the filter and were collected on the SPE device. Subsequently, naphthalene compounds in the SPE device and the filter were eluted with acetone, followed by quantification with HPLC. The results indicated that the inclusion in solid-state β-CD suppressed the evaporation of naphthalene compounds. In addition, the inclusion effect was stronger for the dry than for the wet CDs. The inclusion effect was also found to increase with temperature.</p>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144798009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yao Fu, Xuejuan Pei, Junhua Cao, Qiang Chen, Shixiong Deng
{"title":"Light-up RNA aptamer-based T-NASBA: a one-pot, label-free strategy for miRNA detection","authors":"Yao Fu, Xuejuan Pei, Junhua Cao, Qiang Chen, Shixiong Deng","doi":"10.1007/s44211-025-00811-y","DOIUrl":"10.1007/s44211-025-00811-y","url":null,"abstract":"<div><p>MicroRNAs (miRNAs) are pivotal regulators of cellular processes, with dysregulation linked to diverse diseases, particularly cancer. Current methods, while effective, are often expensive, complex, and require sophisticated equipment. To address these limitations, we developed a label-free, one-pot miRNA detection platform integrating toehold-mediated strand displacement (TMSD) with nucleic acid sequence-based amplification (NASBA). This method utilizes a TMSD-regulated hairpin Primer1 that selectively responds to target miRNA, triggering NASBA to generate a light-Up RNA aptamer for real-time, target-dependent fluorescence signaling-eliminating the need for fluorophore-labeled probes or additional modifications. By systematic optimization of the reaction conditions, the platform achieved a detection limit of 4.31 pM, with a strong linear correlation between fluorescence intensity and miRNA concentration over a range from 10 pM to 1 nM. The platform also demonstrated excellent reproducibility and precision in spike-and-recovery tests with human serum, with recovery rates between 99.85<span>(%)</span> and 108.28<span>(%)</span>. T-NASBA provides a novel, cost-effective, and label-free platform for miRNA detection, offering a simple alternative that requires no complex instrumentation. This makes T-NASBA ideal for a wide range of applications, including point-of-care diagnostics and research, further advancing the field of miRNA-based diagnostics and monitoring.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1607 - 1616"},"PeriodicalIF":2.0,"publicationDate":"2025-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144783275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lindan Gong, Yan Sun, Hongju Zhang, Junqing Li, Aohui Qin, Lu-an Fan
{"title":"A conjugated pyridine diimine fluorene-based polymer for the detection of furaltadone","authors":"Lindan Gong, Yan Sun, Hongju Zhang, Junqing Li, Aohui Qin, Lu-an Fan","doi":"10.1007/s44211-025-00829-2","DOIUrl":"10.1007/s44211-025-00829-2","url":null,"abstract":"<div><p>The potential risks posed by antibiotics to human health and the ecological environment have long been a major public concern. Consequently, developing probe technologies capable of efficiently detecting trace levels of antibiotics in environments has emerged as a critical research priority. In this study, a conjugated fluorene-based pyridine diimine polymeric probe (FPD) was employed as a fluorescent probe for the specific recognition and detection of furaltadone. Experimental results showed that FPD rapidly interacts with furaltadone, resulting in a significant fluorescence quenching of FPD, and its fluorescence intensity could quickly reach a stable state. In the ethanol-PBS mixed solution system, the fluorescence quenching efficiency of FPD exhibits an excellent linear relationship with furaltadone concentrations ranging from 0 to 12 µM, achieving a detection limit as low as 0.0490 µM. In the presence of interfering substances, FPD maintains superior selectivity and anti-interference capability. Furthermore, a recovery experiment was conducted by spiking furaltadone into egg white, yielding recovery rates ranging from 97.29% to 104.22%, with a relative standard deviation (RSD) of less than 3.73%. This study develops a novel and reliable method for the efficient and precise detection of furaltadone, demonstrating broad application potential.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1659 - 1668"},"PeriodicalIF":2.0,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144758899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Simultaneous determination of mumefural and citric acid in Japanese apricot fruit juice concentrate using LC with intramolecular excimer-forming derivatization","authors":"Hideyuki Yoshida, Yuka Imura, Sayaka Minematsu, Misaki Ono, Reiko Koga, Hitoshi Nohta","doi":"10.1007/s44211-025-00822-9","DOIUrl":"10.1007/s44211-025-00822-9","url":null,"abstract":"<div><p>Mumefural (MF) which is one of the citrate esters with 5-hydoxymethyl-2-furfural is a component of Japanese apricot fruit juice concentrate (plum extract). A selective LC-fluorescence detection method was developed for the simultaneous quantification of MF and citric acid in plum extracts using intramolecular excimer-forming derivatization. Analytes were derivatized to their corresponding polypyrene derivatives using 4-(1-pyrene)butyric hydrazide (PBH) in the presence of condensation reagent, separated by reversed-phase LC, and detected in the pyrene-excimer fluorescence region (Ex/Em, 345/475 nm). The detection limits (<i>S</i>/<i>N</i> = 3) for the analytes were sub-picomole levels per 10-μL injection volume. The method was applied for the determination of MF and citric acid in plum extracts and a typical plum wine with a simple pretreatment. Large amounts of citric acid were detected in the plum extracts and the plum wine, whereas MF was detected only in the commercial plum extracts.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 9","pages":"1547 - 1553"},"PeriodicalIF":2.0,"publicationDate":"2025-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144740987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Direct visualization of phase-separation multiphase flow in a silica bead-packed microchannel using fluorescence microscopy","authors":"Yuya Yamashiro, Takeshi Iharada, Kazuhiko Tsukagoshi","doi":"10.1007/s44211-025-00830-9","DOIUrl":"10.1007/s44211-025-00830-9","url":null,"abstract":"<div><p>We previously developed a high-performance liquid chromatography (HPLC) system employing phase-separation multiphase flow (PSMF) as the eluent, referred to as the phase-separation mode in HPLC. However, direct visualization of the flow behavior within the HPLC column had not yet been achieved. In this study, we directly visualized the PSMF behavior in a silica bead-packed microchannel using fluorescence microscopy. A two-phase separation mixed solution composed of 1-butyl-3-methylimidazolium chloride [(C<sub>4</sub>mim)Cl, an ionic liquid], K₂HPO₄, and water, with Eosin Y as a fluorescent dye, was introduced into a microchannel (200 μm wide, 40 μm deep) packed with 10 μm silica beads. Phase separation was induced by cooling from 40 to 25 °C, resulting in an ionic liquid-rich phase containing Eosin Y and a K<sub>2</sub>HPO<sub>4</sub>-rich phase. Fluorescence microscopy equipped with a CMOS color camera enabled visualization of the flow distribution. When the ionic liquid-rich solution was used, non-fluorescent (black) circular regions approximately 10 μm in diameter—corresponding to the silica beads—were observed, surrounded by green fluorescent areas resulting from the distribution of Eosin Y in the ionic liquid phase. These observations indicate that the ionic liquid-rich phase predominantly flows away from the surfaces of the beads. Conversely, when the K<sub>2</sub>HPO<sub>4</sub>-rich solution was used, green fluorescent regions appeared at the bead locations, surrounded by non-fluorescent areas. This indicates that the ionic liquid-rich phase, which contains Eosin Y, preferentially flows near the surfaces of the silica beads. These results provide the first direct visual evidence of PSMF behavior within a particle-packed microchannel. The findings support the proposed flow dynamics of PSMF in HPLC columns and validate the separation mechanism of the phase-separation mode.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1689 - 1694"},"PeriodicalIF":2.0,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144726507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ke Lv, Weitao Wang, Li Zhang, Xi Zhou, Hongyan Yu, Xiaole Han, Li Wang, Guoming Xie, Gang Yang
{"title":"A dual-antibody sandwich immunoassay using upconversion nanoparticles and magnetic beads for fibrinogen detection","authors":"Ke Lv, Weitao Wang, Li Zhang, Xi Zhou, Hongyan Yu, Xiaole Han, Li Wang, Guoming Xie, Gang Yang","doi":"10.1007/s44211-025-00826-5","DOIUrl":"10.1007/s44211-025-00826-5","url":null,"abstract":"<div><p>Fibrinogen is a vital biomarker for coagulation disorders, with reduced levels increasing bleeding risk and mortality, requiring rapid detection for early diagnosis. Enzyme-linked immunosorbent assay (ELISA) is commonly employed in clinical environments; however, its prolonged processing duration and insufficient sensitivity hinder its utility for swift diagnostics. We addressed these limitations by creating a dual-antibody sandwich immunoassay that employs upconversion nanoparticles (UCNPs) and magnetic beads (MBs) for the precise and sensitive detection of fibrinogen. The enhanced analytical performance of the method is attributed to the use of UCNPs and MBs. UCNPs enhance the signal-to-noise ratio by emitting visible light under near-infrared excitation, which reduces background interference from autofluorescence and light scattering in biological samples. Meanwhile, MBs facilitate specific enrichment of fibrinogen by selectively capturing the target analyte, enabling efficient isolation from complex sample matrices. This synergy improves sensitivity and specificity, achieving a 2 ng/mL detection limit with a 15-fold sensitivity increase, simpler operation, and shorter detection time compared to conventional ELISA kits. This platform offers a robust solution for fibrinogen detection, with potential for broad application in clinical diagnostics.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1647 - 1657"},"PeriodicalIF":2.0,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144681898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a sensor-compatible vascular microphysiological system for metabolic monitoring during drug-induced endothelial injury","authors":"Yuning Fu, Ryota Okitsu, Yuji Nashimoto, Yasuhiko Shinoda, Yoshinobu Utagawa, Masateru Yamazaki, Koki Nakaya, Kosuke Ino, Hirokazu Kaji","doi":"10.1007/s44211-025-00825-6","DOIUrl":"10.1007/s44211-025-00825-6","url":null,"abstract":"<div><p>Endothelial metabolism is closely linked to vascular function and is often altered in response to pathological stimuli. Although vascular microphysiological systems (MPS) offer a promising in vitro platform for modeling vascular environments, the integration of real-time metabolic monitoring remains technically challenging. Enzyme-based electrochemical sensors are well-suited for detecting metabolites, such as glucose and lactate; however, their direct incorporation into culture systems is limited by the inactivation of enzymes under culture conditions. In this study, we investigated a vascular MPS with a sensor-compatible design to support future integration of printed enzyme-based biosensors. The device features a stacked open-bottom architecture that enables the integration of biosensors beneath the endothelial layer after monolayer formation, thus minimizing sensor exposure during culture. We validated the formation of an endothelial monolayer on a porous polyurethane membrane with a mortar-like structure and confirmed its compatibility with a model sensor substrate. As a preliminary step toward sensor-based metabolic analysis, we quantified glucose consumption and lactate production during endothelial monolayer formation and upon exposure to Minoxidil and Hydralazine, drugs known to induce vascular injury. These findings demonstrate the feasibility of sensor-compatible vascular MPS and provide foundational data to support the future development of integrated platforms for real-time metabolic monitoring in drug toxicity studies.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":"41 10","pages":"1617 - 1625"},"PeriodicalIF":2.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144658168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}