Analytical Methods最新文献

Glycosylated RNAs (glycoRNAs) are a groundbreaking discovery in glycobiology, extending the diversity of known glycoconjugates beyond proteins and lipids. Accumulating evidence indicates their pivotal roles in cellular communication, immune regulation, and disease pathogenesis, highlighting their promise as novel biomarkers and therapeutic targets. Robust and sensitive detection methods are crucial for deciphering glycoRNA glycosylation patterns and elucidating their physiological and pathological functions. Despite the development of diverse analytical techniques, a systematic evaluation of glycoRNA detection strategies remains lacking. To address this gap, in this review, we comprehensively summarize recent methodological advances, categorizing the published approaches based on their glycan-targeting recognition mechanisms and critically assessing their principles, applications, strengths, and limitations. We also sketch the key challenges and future development directions. This review aims to provide a timely and informative guide for researchers in this rapidly evolving area.

A rapid method has been developed for the determination of 17α-ethinylestradiol and drospirenone in contraceptive formulations. The method is based on the direct coupling of a programmed temperature vaporizer inlet to a quadrupole mass spectrometer via a deactivated fused silica tube (10 m × 0.18 mm) that is maintained at 275 °C throughout the entire analysis. The inlet is equipped with a baffled glass liner coated with Siltek™ and the injection is performed in split mode (ratio 1 : 10). The data acquisition time was only 1.0 min per sample, allowing for the high-throughput quantification of active principles in contraceptive pills in minimal time. The goal is to apply this strategy as a screening tool in quality control processes, limiting the use of the more costly and time-consuming chromatographic methods to those pills showing anomalous results, thus optimizing laboratory resources. Sample treatment involved a fast ultrasound-assisted solid–liquid extraction, and both sample preparation and instrumental conditions were optimized. The determination of the active principles was performed using the standard addition method. Accuracy, expressed as recovery percentage relative to the mass of active principle declared by the manufacturer, varied between 80% and 120%. Intra- and inter-day precision were adequate, with values of relative standard deviation (% RSD) equal to or less than 9% and 11%, respectively. Furthermore, the sustainability profile of the proposed rapid method was evaluated using the HEXAGON algorithm, which demonstrated that the PTV-MS method contributes to sustainable development by benefiting both the environment and society.

Camellia oil is highly valued for its nutritional benefits, but its premium market position has led to frequent mislabeling of geographical origin. To assess the feasibility of tracing camellia oil origin using GC-IMS combined with chemometrics, 66 samples from 11 representative production areas across 7 provinces in China were collected and analyzed. Clustering and discriminant analyses were conducted at both the province and city levels. PCA revealed clear clustering by province, with even greater differentiation when the origin was specified at the city level. The PLS-DA model based on VOC profiles achieved recognition accuracies of 96.7% (province level) and 100% (city level), while the successive projections algorithm (SPA)-PLS-DA model achieved 100% and 98.5%, respectively. The findings demonstrate that GC-IMS combined with chemometrics is a feasible and effective method for camellia oil origin traceability, providing technical support for the certification of geographical indications and food safety supervision.

Adsorbents with significant adsorption capacity and high selectivity are required to identify and eliminate heavy metal ions from the environmental and food samples under study. For this purpose, in the present work a new adsorbent, graphitic carbon nitride g-C₃N₄ hybrid with CaAl layered double hydroxide, was effectively synthesised using an easy hydrothermal co-precipitation procedure and applied for Pb²⁺ determination in food and water samples using dispersive solid phase-microextraction (DSP-µE) via FAAS. The as synthesized CaAl-LDH@g-C₃N₄ nanocomposite characteristics were examined using XRD, SEM, SEM-EDX and FTIR. Significant analytical parameters were optimised such as pH 8, adsorbent quantity 10 mg, and adsorption and elution times 30 and 60 s, respectively. Additionally, a sample volume of 20 mL and an eluent volume of 2 mL were used with an elution solvent of 0.5 M HNO₃. A matrix effect study was also performed as verification of the developed method. A limit of detection (LOD) of 0.54 µg L⁻¹, a limit of quantification (LOQ) of 1.79 µg L⁻¹, an enrichment factor (EF) of 10.69 and a preconcentration factor (PF) of 10 were determined. The % RSD (< 10%) with an R² value of 0.999 has proven the linearity and high accuracy of the developed method. ComplexMoGAPI evaluation (score 79) confirmed the excellent greenness of the proposed method. Standard reference materials (SRMs) were used to affirm the accuracy of the method. Different instant noodle samples, and tap water samples were analysed for their Pb²⁺ content, allowing for the successful determination of Pb²⁺ levels in them.

Dipeptidyl peptidase-IV (DPP-IV) is critical for drug metabolism and physiological regulation. In terms of differences in DPP-IV among species, mouse and human DPP-IV share a high degree of similarity, and mice are typically used as the optimal animal model for conducting the relevant pharmacological evaluations and biological function studies. Herein, a detection method is developed using the fluorescent probe GP-BAN and mouse tissue S9 fraction (enzyme source) to rapidly quantify DPP-IV activity in mouse tissues. The method was validated for specificity, linearity and precision, and the metabolite BAN showed good linearity in the 0–20 µM range using a weighted (1/x) least squares linear regression model (r² = 0.9996), with an LOD of 5.5 nM and LOQ of 16.7 nM. In C57 mice, the DPP-IV activity in 14 tissues/organs (including the liver, kidney, thymus, and small intestine) differed significantly: the thymus had the highest activity (2.64 nM µg⁻¹ protein per min), followed by the liver, kidney and small intestine. Enzyme kinetics showed that the K_m of GP-BAN for mouse DPP-IV was 34.05 µM, which is close to that of human liver microsomes (HLM, 41.46 µM), indicating cross-species substrate binding consistency. ELISA confirmed that DPP-IV protein expression correlated positively with activity in the liver, kidney and thymus (r > 0.92, p < 0.001). This sensitive, species-translatable assay and its organ-specific activity/kinetic data support mouse models in preclinical DPP-IV studies, improving cross-species extrapolation predictability in physiological research.

This paper describes a new analytical approach for determining gamma-hydroxybutyric acid (GHB) in biosamples using liquid chromatography-mass spectrometry (LC-MS) following derivatization with N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC). The derivatization procedure is simple, rapid, reproducible, inexpensive, and safe. It allows for a complete variation of GHB chemical characteristics (from hydroxyacid to N-acylurea) with a molecular weight increase from 104 to 259 u and the introduction of 3 nitrogen atoms. These modifications promote the protonation of the analytes in the MS electrospray ion source, enabling MS detection under positive ionization conditions. Liquid chromatography-high-resolution accurate-mass Orbitrap mass spectrometry (LC-HRAM-Orbitrap-MS) measurements demonstrated that derivatization produces two GHB-EDC derivatives with the same exact mass (MH⁺ ions at m/z 260.1968) and experimental isotopic patterns overlapping each other and superimposable to the calculated one. Thus, they share an identical elemental composition (C₁₂H₂₅O₃N₃) but have different molecular structures (GHB-EDC_A and GHB-EDC_B). Equivalent results were obtained for D₆-GHB: the production of two deuterated N-acylureas (D₆-GHB-EDC_A and D₆-GHB-EDC_B), with MH⁺ ions at m/z 266.2341, superimposable experimental and calculated isotopic patterns, elemental composition C₁₂H₁₉D₆O₃N₃, and different molecular structures, mirroring those of GHB-EDC_A and GHB-EDC_B. After optimizing the derivatization conditions (reaction solvent, reaction temperature and time, and volume and concentration of the derivatizing agent) the final procedure involves reacting with 10 mM aqueous EDC, at 45 °C for 15 minutes. GHB-EDC derivatives were found to be highly stable over time (at least 15 days), even at room temperature. Three preliminary analytical methods for the determination of endogenous and exogenous GHB levels in urine, blood, and hair samples were developed.

Acute kidney injury (AKI) is a common syndrome among critically ill patients with high incidence and high mortality, characterized by elevated serum creatinine (SCr) and uric acid (UA) levels. Given that xanthine is a key intermediate in nucleotide metabolism and the direct precursor of UA, profiling of nucleotide metabolic dysregulation in AKI remains largely unexplored. Using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), we simultaneously quantified 29 nucleotide intermediates both in plasma and matched urine samples from 58 propensity score-matched pairs of AKI and non-AKI (NAKI) critically ill patients. Compared with NAKI controls, AKI patients showed decreased levels of 7 urinary nucleotide intermediates and increased levels of 4 plasma metabolites. Urinary nucleotide levels correlated more strongly with SCr and estimated Glomerular Filtration Rate (eGFR) than their plasma counterparts. Elevated urinary xanthine and other 5 metabolites were identified as protective factors for AKI, while elevated plasma adenine, thymine and cytosine were risk factors. A combination of urinary guanine and xanthine with plasma thymine discriminated AKI risk with an area under the curve (AUC = 0.880, 95% CI = 0.800–0.934). Interestingly, alterations in nucleotide intermediates influenced AKI occurrence mediated by SCr, eGFR, UA, urea and aspartate aminotransferase (AST), with hypoxanthine and thymidine exerting specifically through AST. In summary, dysregulated nucleotide metabolism was closely associated with AKI onset and participated in kidney-liver crosstalk through modulation of liver function, providing new mechanistic insights into AKI pathogenesis.

Liquid crystal monomers (LCMs) are emerging organic pollutants to which humans are chronically exposed at low doses. Accurate quantification of LCMs in biological matrices remains challenging due to their low environmental concentrations and significant matrix effects. By optimizing the GC-MS conditions and the sample pretreatment process, this study developed a novel approach for robust determination of three LCMs including 2,3-difluoro-4-(trans-4-propylcyclohexyl) butoxybenzene (3cH4OdFP), 4-propoxy-4′-cyanobiphenyl (3OCB), and 4-ethyl-4′-(4-propylcyclohexyl)-1,1′-biphenyl (3cH2B) in mouse serum, brain, heart, liver, spleen, lung, and kidney tissues. Serum samples were extracted with n-hexane, while tissues were extracted using acidified acetonitrile followed by QuEChERS cleanup. Separation was achieved on a DB-17HT column, and detection was performed in selected ion monitoring (SIM) mode of GC-MS. The method demonstrated good linearity (r² > 0.995) from 0.5 ng mL⁻¹ to 200 ng mL⁻¹. Limits of detection were 0.2 ng g⁻¹ for tissues and 1.0 ng mL⁻¹ for serum. Average recoveries ranged from 74.32% to 126.04%, with intra-day and inter-day precision in the range 2.17–18.53% and 3.75–19.13%, respectively. The validated method was successfully applied to exposed mice, revealing widespread tissue distribution of the three LCMs. The concentration ranges in serum and tissues were as follows: 3cH4OdFP (Not Detected (ND)–6.1978 µg g⁻¹), 3OCB (ND–30.1073 µg g⁻¹), and 3cH2B (ND–67.3851 µg g⁻¹). The spleen exhibited a higher accumulation potential. This sensitive and reliable method provides a robust tool for monitoring LCMs in toxicological research and assessing internal exposure, while also revealing their potential immunotoxicity.

Addressing the challenges of strong matrix interference, cumbersome procedures, and urgent demand for on-site rapid detection in the analysis of tetracycline antibiotic (TCA) residues in milk, this study aims to develop an efficient, rapid screening method based on the amplified luminescence proximity homogeneous assay (AlphaLICA) technology for the direct detection of tetracycline (TC) and other TCA residues in milk. By conjugating TC–BSA complexes to receptor microspheres and goat anti-mouse IgG antibodies to donor microspheres, this approach effectively overcomes interference from milk fat and casein, enabling wash-free, homogeneous detection. This method exhibits high sensitivity (limit of detection (LOD): 0.16 ng mL⁻¹; limit of quantification (LOQ): 0.83 ng mL⁻¹), with a linear range of 0.83–32 ng mL⁻¹. Spiked recovery rates reached 100.95–114.78% (relative standard deviation (RSD) ≤ 8%), while intra- and inter-batch coefficients of variation (CV) ranged from 3.89%–13.24% and 4.34–13.52%, respectively. Cross-reactivity with non-TC antibiotics remained low (CR ≤ 10.68%). Compared to the traditional enzyme-linked immunosorbent assay (ELISA, 75 minutes, requiring washing), this method requires only 10 minutes and is wash-free. The results of actual sample testing showed high consistency with the reference method (Y = 0.7685X + 0.4623, r² = 0.952, p < 0.001). This study provides a reliable technical solution for high-throughput rapid field monitoring of TCA residues in milk.

Paraquat is a highly polar herbicide that can be detected in environmental water samples due to its unauthorized use in agriculture and its high mobility in aquatic systems. Its determination at trace levels remains analytically challenging, particularly when using conventional multiresidue methods based on reversed-phase liquid chromatography, which often requires ion-pairing reagents that compromise the method precision. In this work, the application of a large-volume injection (LVI) strategy was exploited for a superficially porous (core–shell) column to enhance the sensitivity of paraquat detection in tap water samples using HPLC with UV detection at 257 nm. The hydrophilic interaction liquid chromatography (HILIC) enabled paraquat retention, with a mobile phase composed of 50 mmol L⁻¹ ammonium formate (pH 3,0) and acetonitrile (25 : 75, v/v). The method employed an injection volume of 50 µL and provided robust quantification of paraquat in tap water, achieving a limit of quantification of 2.5 µg L⁻¹, excellent linearity (R² = 0.9999), and recovery values between 98.3 and 107.0%, without matrix effects. The strategy crucially avoided SPE preconcentration and waste generation. The proposed method circumvented the sample volume limitations typically associated with core–shell columns, achieving a simple and cost-effective approach for paraquat environmental monitoring.