Search

Abnormal levels of catecholamine (CA) neurotransmitters and their metabolites in biological fluids can lead to various neurological disorders. Herein, a boric acid‐functionalized hypercrosslinked polymer was prepared and utilized as a sorbent for the dispersive solid‐phase extraction of CAs and their metabolites in rat serum. By combination with a high‐performance liquid chromatography‐fluorescence detector, the extraction parameters for the seven target analytes were optimized. Under the optimal extraction condition, the methodology for the quantitative analysis of CAs and their metabolites in rat serum samples was established. The limits of detection and limits of quantification were found to be in the ranges of 0.010–0.015 and 0.033–0.050 ng/mL, respectively. The results demonstrated satisfactory recoveries, with values ranging from 88.02% to 113.27%, accompanied by relative standard deviations within the range of 2.69%–9.59%. In addition, the method showed good anti‐interference ability (matrix effect ranged from 2.64% to 18.07%). The developed method was validated for the determination of CAs and their metabolites in normal and Alzheimer's disease model rats' serum, which proved the promising application of the method for CAs neurotransmitter analysis in biological samples. [ABSTRACT FROM AUTHOR]

Herein, a magnetic borate‐functionalized MXene composite with multiple boronic affinity sites was fabricated by embedding Fe3O4 nanoparticles with 4‐formylphenylboronic acid functionalized Ti3C2Tx nanosheets and served as sorbent for the simultaneous extraction of catecholamines (CAs) in urine samples. The morphology and structure of the magnetic materials were investigated using scanning microscopy, vibrating sample magnetometer, X‐ray photoelectron spectrometer, and X‐ray diffraction. The introduction of polyethyleneimine can amplify the bonded boronic acid groups, thereby effectively improving the adsorption capacities for CAs based on the multiple interactions of boronic affinity, hydrogen bonding, and metal coordination. The adsorption performance was investigated using the kinetics and isotherms models, and the main parameters that influence the extraction efficiency were optimized. Under the most favorable magnetic solid‐phase extraction condition, a sensitive method for the analysis of CAs in urine samples was developed by combining magnetic solid‐phase extraction conditions with high‐performance liquid chromatography detection. The findings illustrated that the proposed approach possessed a wide linearity range of 0.05–250 ng/mL with an acceptable correlation coefficient (R2 ≥ 0.9984) and detection limits of 0.010–0.015 ng/mL for the target CAs. The research not only provides a notable composite with multiple boronic affinity sites but also offers an effective and feasible measure for the detection of CAs in biological samples. [ABSTRACT FROM AUTHOR]

In this study, a new Ti3C2Tx‐coated fiber was synthesized and utilized as coatings for solid‐phase microextraction of seven polychlorinated biphenyls. The as‐produced multilayered Ti3C2Tx MXene was characterized by X‐ray diffractometer, thermos‐gravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. It is noteworthy that the Ti3C2Tx showed some attractive features including unique 2D layered structures, large surface area, good hydrophilicity, and rich active recognition sites, endowing it has a high affinity towards the target polychlorinated biphenyls. Subsequently, the affecting parameters on the extraction efficiency of polychlorinated biphenyls were optimized. Under the optimal conditions, a novel method for the analysis of polychlorinated biphenyls in water samples was proposed. The Ti3C2Tx‐coated fiber‐based solid‐phase microextraction method showed good linearity (r2 > 0.9928), high enrichment factors (268–442), low limits of detection (0.06–0.15 ng/L), and satisfactory repeatability (RSDs < 7.5%) for the polychlorinated biphenyls. The excellent method recoveries were in the range of 90.0–98.4, 92.0–98.2, and 92.0–98.0% for river water, lake water, and tap water samples, respectively. These results suggested that the proposed Ti3C2Tx‐coated fiber‐based method represents a promising alternative for the analysis of polychlorinated biphenyls. [ABSTRACT FROM AUTHOR]

In this study, a new Ti 3 C 2 T x -coated fiber was synthesized and utilized as coatings for solid-phase microextraction of seven polychlorinated biphenyls. The as-produced multilayered Ti 3 C 2 T x MXene was characterized by X-ray diffractometer, thermos-gravimetric analysis, scanning electron microscopy, and energy dispersive spectroscopy. It is noteworthy that the Ti 3 C 2 T x showed some attractive features including unique 2D layered structures, large surface area, good hydrophilicity, and rich active recognition sites, endowing it has a high affinity towards the target polychlorinated biphenyls. Subsequently, the affecting parameters on the extraction efficiency of polychlorinated biphenyls were optimized. Under the optimal conditions, a novel method for the analysis of polychlorinated biphenyls in water samples was proposed. The Ti 3 C 2 T x -coated fiber-based solid-phase microextraction method showed good linearity (r 2  > 0.9928), high enrichment factors (268-442), low limits of detection (0.06-0.15 ng/L), and satisfactory repeatability (RSDs < 7.5%) for the polychlorinated biphenyls. The excellent method recoveries were in the range of 90.0-98.4, 92.0-98.2, and 92.0-98.0% for river water, lake water, and tap water samples, respectively. These results suggested that the proposed Ti 3 C 2 T x -coated fiber-based method represents a promising alternative for the analysis of polychlorinated biphenyls., (© 2021 Wiley-VCH GmbH.)