Analytical Methods最新文献

Chemiluminescence (CL) provides outstanding analytical performance due to its background-free nature and exceptional sensitivity and selectivity. The forensic luminol chemiluminescence test is one of the most commonly used methods for detecting latent bloodstains. However, its applications are limited by the insolubility of luminol under physiological conditions. In this study, m-carboxy luminol with its hydrophilic design was found to overcome these limitations and showed a chemiluminescence intensity higher than that displayed by any other luminol-based CL assay. The superior CL performance of m-carboxy luminol encouraged us to further apply this derivative for imaging bloodstains, with the results implying excellent application prospects for m-carboxy-luminol-containing imaging solutions in criminal investigations.

Lung carcinogenesis (LC) is a kind of disease, which threatens human health seriously. Metabolomic research on bio-fluids and tissues is crucial for elucidating the pathogenesis of LC and understanding the therapeutic mechanisms of medicines. In this study, we established a rat model for LC by induction with urethane. The anti-tumor effect of Qi-Yu-San-Long decoction (QYSLD) on LC was assessed through morphology changes, histopathological examination, and inflammation levels. Utilizing the metabolomics technique based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS), we investigated the metabolic changes in the plasma and lungs of LC rats and explored the ameliorative effects of QYSLD on the molecular levels. Functional biomarkers associated with QYSLD in LC rats were identified and relatively quantified. The results manifested that, in contrast to the control group, the number of tumor nodules and inflammation levels in the LC model group increased significantly, indicating that the LC rat model was successfully built. After QYSLD treatment, the morphology and lesion degree of LC rats were greatly improved. A total of 23 differential metabolites between the control group and the urethane-induced LC group were screened through plasma and lung tissue metabolomics studies, of which 20 were considerably modulated after QYSLD treatment. Metabolic pathway analysis revealed that the pathogenesis of LC and the therapeutic effects of QYSLD primarily involved glycerophospholipid metabolism, ether lipid metabolism, sphingolipid metabolism, and arachidonic acid metabolism. Our findings provide a potential intracellular metabolite profile for urethane-induced LC and demonstrate that QYSLD exerts anti-tumor effects on LC by modulating multiple metabolic pathways.

A Schiff base fluorescent probe, HTT, based on a sulfonylhydrazone structure was designed and synthesized for the sensitive and selective detection of Cu²⁺. The probe HTT exhibits good anti-interference performance toward Cu²⁺ in the presence of a variety of metal ions. After the addition of Cu²⁺, it can quickly respond within 40 seconds, and the fluorescence detection limit is 1.10 nM. The coordination ratio of probe HTT and Cu²⁺ is 2 : 1, and the coordination reaction between CN, SO and Cu²⁺ limits the formation of hydrogen bonds between the hydroxyl group and CN, disrupting the spatial coplanar effect of the probe molecule and thereby inducing fluorescence quenching. The probes can be recovered and reused using EDTA for the detection of Cu²⁺. The probe was also applied to the successful monitoring of Cu²⁺ in living cells and real water samples.

An efficient electrochemical molecularly imprinted sensor for the detection of tetracycline (TC) was prepared using ZnO/MIP. ZnO nanomaterials with large surface area improved the electrochemical detection performance and also increased the binding sites of the TC molecularly imprinted polymeric membrane. The TC molecularly imprinted polymeric membrane with pyrrole as the functional monomer specifically binds to TC and thus detects TC in the sample. In this study, the electrochemical performance of ZnO/MIP was evaluated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal conditions, ZnO/MIP showed a wide detection range. The detection range was 0.1-100 nM, and the detection limit was 0.02 nM with R² reaching 0.9974. ZnO/MIP has good selectivity, stability, and reproducibility. The recovery of tetracycline in milk was 97-112%.

Safflower seed oil is expensive, and there are issues in the market such as the adulteration with cheaper edible oils, leading to inferior products. Near-infrared spectroscopy (NIR) is a non-destructive analytical method with the advantages of being fast, non-destructive, and pollution-free. However, in the case of low-concentration adulterated oil, the main components and their contents are nearly identical to those in pure oil, and the spectral feature peaks of the samples are similar, making it difficult for conventional analysis methods to select effective characteristic variables. Extreme Learning Machine (ELM), as a single-hidden-layer feedforward neural network model, possesses strong feature extraction and model representation capabilities. However, its random initialization of weights and biases leads to the issue of blind training. The Sparrow Search Algorithm (SSA) can effectively optimize the random initialization problem in ELM, but it is prone to issues such as being trapped in local optima and slower convergence. This study proposes a novel quantitative adulteration analysis model for safflower seed oil (ISSA-ELM), which combines ELM with an improved Sparrow Search Algorithm (ISSA). In the experiment, safflower seed oil was used as the base oil, and peanut oil, corn oil, and soybean oil were gradually added to prepare adulterated oil samples. To ensure the resolution of experimental samples and accurately capture spectral variations in the low-concentration range, a concentration gradient of 2% was used for adulteration levels between 2% and 70%, while a 5% gradient was applied for concentrations exceeding 70%. Each type of adulterant had 42 gradient concentrations, with 6 samples per concentration, totaling 252 samples. Original spectral data were collected, and the samples were randomly divided into a training set (70%) and a testing set (30%). Different preprocessing methods and feature extraction techniques were combined to discuss the results of three adulteration analysis models: PLS, SSA-ELM and ISSA-ELM. The final experimental results show that compared to the safflower seed oil adulteration prediction model based on SSA-ELM (R² = 0.8938, RMSE = 0.0835, RPD = 2.9018)and PLS(R_P² = 0.9015, RMSEP = 0.0876, RPD = 3.0128), the model based on ISSA-ELM (R_P² = 0.9934, RMSEP = 0.0207, RPD = 10.1457) offers higher prediction accuracy and stability, and the error detection limit of ISSA-ELM can reach 2%. The ISSA optimized the SSA's tendency to reduce population diversity, slow convergence, and get stuck in local optima in the later stages of iteration, greatly enhancing the global optimization ability of the algorithm. Therefore, ISSA-ELM can effectively identify adulterated safflower seed oil, providing a technological pathway and basis for research into the adulteration of safflower seed oil.

This study pioneers a sustainable strategy for synthesizing yellow-emissive carbon dots (Y-CDs) using expired rabeprazole sodium tablets, thereby transforming pharmaceutical waste into valuable nanomaterials. The as-prepared Y-CDs displayed a high quantum yield of 48.89%, strong photostability, and pronounced environmental resilience. These attributes establish their potential as reliable fluorometric probes. The fluorescence of Y-CDs was effectively quenched by vitamin B12 through a dual mechanism involving the inner-filter effect (IFE) and static quenching. Under optimized conditions, the fluorescence intensity ratio (F⁰/F) showed excellent linearity in the range of 0-300 μM and achieved a detection limit of 8.0 nM (S/N = 3). The developed method demonstrated high accuracy (recoveries of 96.8-105.9%) for pharmaceutical formulations. Beyond its analytical merits, this work introduces a green nanotechnology route that addresses pharmaceutical waste management by converting expired drugs into efficient, multifunctional nanomaterials.

Recent uses of chlorine gas in violation of the Chemical Weapons Convention are difficult to identify through chemical analysis as unique signatures of exposure have not been identified. We exposed living pine seedlings and English ivy to chlorine gas, extracted the pine needles, and analyzed the extracts by liquid chromatography-time of flight mass spectrometry (LC-qTOF) and comprehensive two-dimensional gas chromatography mass spectrometry (GC×GC-TOF). Data from exposed seedlings was compared to unexposed seedlings and bleach-treated seedlings using commercial and Battelle proprietary software to identify unique or elevated markers of exposure. Battelle also used targeted mass spectrometry to evaluate 3-chlorotyrosine and 3,5-chlorotyrosine as chlorine exposure biomarkers that were expected to be present in exposed pine needles. We discovered ten (10) chlorine exposure biomarkers in chlorine gas-exposed pine needle and ivy leaf extracts using survey mass spectrometry methods. Additional survey mass spectrometry analysis suggested additional biomarkers (chlorinated glycosylated flavonoid analogs) may be present but that sufficient levels were not generated for detection in extracts from the chlorine gas-exposed samples. Targeted analysis for 3-chlorotyrosine and 3,5-dichlorotyrosine indicated presence of 3-chlorotyrosine in extracts from exposed ivy.

Leather has been widely used since ancient times, and the discovery of ancient leather is of great value for studying the origin and development of costume culture. However, due to contamination and degradation of leather relics in the buried environment, traditional analytical methods face challenges in detecting microtraces of ancient leather. Therefore, an immunosensor based on a dual recognition strategy was proposed in this work for the detection of leather artifacts at archaeological sites. Anti-collagen antibodies type I (Anti-COL I) and type II (Anti-COL II) were prepared through animal immunization. Next, the antibodies on the surfaces of magnetic beads (MBs) and polystyrene microspheres (PMs) underwent a specific binding reaction with the antigens, which were magnetically separated and placed in sucrose solution, further catalyzed by sucrose invertase on functionalized polystyrene microspheres (FPMs). Finally, the collagen concentration was detected using a personal glucose meter (PGM). The prepared immunosensor exhibited excellent sensitivity, specificity, and stability, with a limit of detection (LOD) of 4.92 ng mL^-1, a relative standard deviation (RSD) of 8.39% for sensitivity, and a linear detection range of 10 ng mL^-1 to 100 μg mL^-1. The coefficient of variation of specificity was less than 4.34%, and the sensor demonstrated a lifespan of up to three weeks. Moreover, the sensor outperforms enzyme-linked immunosorbent assay (ELISA) in terms of accuracy, specificity, and reproducibility. Therefore, this sensor provides a new strategy for the on-site detection of leather artifacts.

Abnormal expression of microRNAs (miRNAs) is commonly considered as an indicator of various physical conditions. To address the separation and quantification of multiple miRNAs, an inter-particle DNA walker amplification coupled with a target self-convert system is developed for simultaneous and sensitive detection of three miRNAs by high-performance liquid chromatography (HPLC). In this work, one DNA-functionalized particle can walk around the other to produce abundant short probes realizing self-conversion of target miRNAs for detection of different short probes. This assay method shows detection limits of 1.5 fM for miRNA-21, 2.1 fM for miRNA-199a and 1.8 fM for miRNA-499. Furthermore, this method demonstrates the capability to selectively discriminate target miRNAs from interfering RNAs, ensuring high specificity under complex experimental conditions. The approach also exhibits exceptional sensitivity, allowing for the detection of low concentrations of target miRNA in human serum samples. With the successful application of this approach to three specific miRNAs, this technique can be further extended to detect other miRNAs in a convenient and efficient way.

Metal organic frameworks (MOFs) and covalent organic frameworks (COFs) represent two burgeoning categories of advanced porous materials that have garnered substantial interest within the scientific community in recent years. Notably, the synergistic effect of MOFs and COFs facilitates their integration into MOF/COF hybrid structures, thereby enhancing performance and broadening their applicability across diverse fields. Herein, we report the development of a novel capillary electrochromatographic coated open tubular column, utilizing a MOF/COF hybrid material (ZIF-93/TpBD) as the stationary phase, to achieve high-resolution separation of six groups of analogues. Both ZIF-93/TpBD-coated open tubular (OT) column and the hybrid stationary phase were characterized using a series of analytical techniques. The outstanding separation performance of the as-prepared OT column was evaluated using alkaline amino acids, sulfonamides, acidic antibiotics, vitamin B, purine compounds and β-blocker analyte groups, under optimal separation conditions. The six groups of analytes achieved baseline separation within 9.5 minutes and achieved high resolution (ranging from 1.50 to 9.71). Furthermore, the run to run, day to day, column to column and batch to batch relative standard deviations of retention time and column efficiency were in the range 0.71-3.91% and 0.49-4.19%, respectively. The ZIF-93/TpBD-coated OT column exhibited remarkable stability after 200 consecutive runs. Finally, a rapid, highly efficient, accurate, and reliable method was developed for the qualitative and quantitative analysis of vitamins B1, B2, B6 and nicotinamide in healthcare settings. This novel hybrid stationary phase, composed of MOF/COF, presents a new avenue for the advancement of chromatographic separation.