Socas-Rodriguez, BarbaraMendiola, Jose A.Angel Rodriguez-Delgado, MiguelIbanez, Elena...
12页
查看更多>>摘要：A B S T R A C T In this work, the application of betaine-based hydrophilic natural deep eutectic solvents (NADESs) as green extraction solvents was proposed for the first time for the evaluation of twelve pesticides in citrus and olive by-products intended to be applied as potential sources of compounds with neuroprotective activity against Alzheimer Disease. Ultrasound-assisted extraction of selected pesticides was followed by separation and determination using gas chromatography coupled to single quadrupole mass spectrometry. Eight NADESs were tested using different hydrogen bond donors (i.e. citric and lactic acid, fructose, glucose, glycerol, propylene glycol, propionic and butanoic acid). Other factors affecting extraction efficiency were also evaluated using a step-by-step approach. Eight mL of a mixture composed of 60% betaine:propylene glycol NADES at a molar ratio 1:4 and 40% of water, as well as 30 min of ultrasound-assisted extraction were selected as the most adequate conditions. The methodology was validated prior to its application in citrus and olive by-products. Recovery values were between 73 and 115% (RSD% < 20%), while limits of quantification of the method were in the range 8.5-128.8 mu g/kg, which demonstrates the suitability of the procedure to determine the selected group of pesticides, usually applied in citrus and olive crops, at the legislated levels. The greenness of the procedure was also evaluated using AGREE calculator. Finally, the whole method was applied for the safety assessment of seven olive leaf samples and seven citrus by-products produced in Spain, finding the presence of several of the evaluated compounds at concentrations higher than the established limits for similar products.(c) 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )
查看更多>>摘要：Antibody fragments and their engineered variants show true potential as next-generation therapeutics as they combine excellent targeting with superior biodistribution and blood clearance. Unlike full antibodies, however, antibody fragments do not yet have a standard platform purification process for large-scale production. Short peptide ligands are viable alternatives to protein ligands in affinity chromatography. In this work, an integrated computational and experimental scheme is described to de novo design 9-mer peptides that bind to Fab fragments. The first cohort of designed sequences was tested experimentally using human polyclonal Fab, and the top performing sequence was selected as a prototype for a subsequent round of ligand refinement in silico. The resulting peptides were conjugated to chromatographic resins and evaluated via equilibrium and dynamic binding studies using human Fab-kappa and Fab-lambda. The equilibrium studies returned values of binding capacities up to 32 mg of Fab per mL of resin with mild affinity (KD similar to 10 -5 M) that are conducive to high product capture and recovery. Dynamic studies returned values of product yield up to similar to 90%. Preliminary purification studies provided purities of 83-93% and yields of 11-89%. These results lay the groundwork for future development of these ligands towards biomanufacturing translation. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：The bovine serum albumin (BSA) was firstly bonded on the surface of graphene quantum dots (GQDs) functionalized silica as the stationary phase named as BSA@GQDs@SiO2 which can perform hydrophilic interaction between the stationary phase and analytes. Characteristic methods including Fourier trans -form infrared spectroscopy (FT-IR), elemental analysis (EA), thermogravimetric analysis (TGA) and scanning electron microscope (SEM) were applied to estimate the chemical bonding results and morphological features of the prepared materials. In the chromatographic evaluation part, the BSA@GQDs@SiO2 column showed excellent separation efficiency for the analysis of hydrophilic compounds involving nucleosides and bases, acids, phenols, quinolones, vitamins and alkaloids, which proved the prepared column can exhibit hydrophilic interaction mode with other interactions including hydrogen bonding and electro-static interaction. What's more, essential experimental approaches were designed to evaluate the retention properties of the prepared column via comparing with a commercial amino column and a prepared GQDs@SiO2 column. Results indicated the prepared column showed excellent separation ability for different kinds of hydrophilic compounds than commercial and single hydrophilic columns. The study showed that BSA@GQDs@SiO2 stationary phase with double hydrophilic materials will be a potential chromato-graphic material for analyzing various hydrophilic analytes. (c) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：A rapid, accurate and novel analytical method based on ultra-high performance supercritical fluid chromatography-tandem mass spectrometry for determination of 22 alternative plasticizers in wrap film was developed. Instrumental analysis and sample preparation procedures were systematically optimized. The targets were separated on Torus 1-AA column (100 mm x 3 mm, 1.7 mu m). Mobile phase A was supercritical carbon dioxide, and mobile phase B was ethanol/methanol (7:3, v/v) containing 0.1% formic acid and 0.5 mM ammonium acetate. Gradient elution was performed. The analytes were extracted by 10 mL n-hexane/dichloromethane (1:1, v/v), and further purified on silica solid phase extraction cartridges. The analytes were quantified by ultra-high performance supercritical fluid chromatography tandem mass spectrometry with electrospray ionization source, and detection was performed on multiple reaction monitoring mode. Two commercially available isotopically-labelled internal standards were used for quantification calibration, and analytes were divided into two groups according to the more appropriate internal standards (chemistry similarity, closeness of retention time).Method validation was performed in terms of recovery, repeatability, linearity, sensitivity and matrix effect. Linearity was assessed using matrix-matched standard calibration. Satisfactory linearity (r 2 > 0.995), intra-day precision (RSDs < 9.6%), inter-day precision (RSDs < 10.9%), recovery (75.6-124.5%) as well as good selectivity was observed. The limits of detection were 0.04-10 mu g/kg, while the limits of quantification were 1.0-50 mu g/kg. Most targets did not show significant matrix effect. Validation results verified that the proposed method was efficient, rapid and sensitive. Eventually it was successfully applied to food wrap film analysis, and results indicated that DEHA, ATBC, DBA and TnBP were the most frequently detected plasticizers in wrap film samples,which was worthy of attention.(c) 2022 Published by Elsevier B.V.
查看更多>>摘要：A novel ultra-hydrophilic zwitterionic-HILIC (ZIC-HILIC) nanosphere (Fe3O4-CG) was synthesized via a one-step hydrothermal strategy, which significantly simplified the conventional multi-step procedures for the preparation of ZIC-HILIC materials. The dual-functional Fe3O4-CG nanosphere exhibited excellent selectivity (molar ratio BSA:HRP = 50 0 0:1), low detection limit (0.05 fmol/ mu L), satisfactory reusability (at least 5 times) and recovery rate (93.7 +/- 2.1%). The binding constant of Fe3O4-CG for HRP is 2.45 +/- 0.32 x 10(-6) M and the theoretical binding capacity is 330 mg g(-1). In addition, the Fe3O4-CG microsphere showed excellent performance in the detection of glycopeptides from real biological samples. Furthermore, 131 glycopeptides related to 71 glycoproteins were selectively enriched from healthy human serum and 180 glycopeptides related to 82 glycoproteins were captured from Alzheimer's disease patients' serum analyzed by Nano-LC-MS/MS. Gene ontology analysis of the biological process and molecular function showed that 21 primitive glycoproteins in glycopeptides captured from Alzheimer's disease patients' serum were meaningfully involved in a variety of neurodegenerative disease-related events, including serine-type endopeptidase inhibitor activity, receptor binding, positive regulation of B cell activation, and platelet activation. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：A comparative study on the uptake of Eu(III) and Am(III) was carried out using four extraction chromatography (XC) resins impregnated with constant weight of the tetra-n-pentyl diglycolamide (TPDGA) ligands, viz. tetra-n-hexyl diglycolamide (THDGA), tetra-n-octyl diglycolamide (TODGA) and tetra-n-decyl diglycolamide (TDDGA) along with C(4)mim Greek ano teleiaNTf(2), a room temperature ionic liquid (RTIL), from nitric acid feed solutions. The uptake of Eu(III) was higher than that of Am(III) while the uptake trend with the four XC resins followed the order: TPDGA > THDGA > TODGA > TDDGA, which was opposite to the alkyl chain length attached to the DGA extractant. When constant moles of the extractants were used, the ob-served trend was TODGA > THDGA > TDDGA > TPDGA. Also, for all the four XC resins, the uptake of both Eu(III) and Am(III) ions increased with increasing nitric acid concentration. The uptake data with all the four resins were fitted into different kinetic and isotherm models which conformed to a pseudo-second order kinetics and Langmuir monolayer sorption isotherm. Furthermore, columns were prepared with these XC resins and were used to obtain breakthrough profiles using a feed solution containing 0.55 g/L Eu(III) in 3 M HNO3. Subsequently, the elution of the loaded metal ion from the column was accomplished with a strippant solution containing 1 M guanidine carbonate + 0.05 M EDTA in distilled water. Elution profiles for all the four resins showed sharp peaks with almost no tailing. (C) 2022 Elsevier B.V. All rights reserved.
查看更多>>摘要：Chromatography is one of the most important separation techniques in analytical chemistry. In which, the separation materials are the core for good separation results. Poly (amide-amine) dendrimers with regu-lar three-dimensional structure, abundant terminal groups, controllable molecule chains, and unique cav-ities appear to have a positive impact on chromatographic separation materials. In the past decades, poly (amide-amine) grafted adsorbents and stationary phases have presented high grafting efficiency, control-lable surface structure, good dispersion, and wide practical applications. In this review, the prepared poly (amide-amine) functionalized separation materials and their applications are systematically summarized. Functions, significance, structure-actvity relationships and benefits of poly (amide-amine) dendrimers in the proposed separation materials are discussed in detail. And we hope to provide a useful reference for the future development of chromatographic separation materials and inspire new discoveries in the study of poly (amide-amine) functionalized materials.
查看更多>>摘要：The use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITYTM UPLCTM system and column, designed to mitigate the chelation, poor peak shape and analyte loss seen with acidic phospholipids was investigated. Compared to a conventional system significant improvements in both sensitivity, recovery and peak shape were obtained following UPLC on a CSH C18 column when the HST was used for the analysis of lysophosphatidic acid (LPA), phosphatidic acid (PA), lysophosphatidylserine (LPS), phosphatidylserine (PS), phosphatidylinositol-monophosphates (PIP), ceramide phosphate (CerP) and sphingoid base phosphate (SPBP). The benefits in chromatographic performance provided by the HST were seen particularly at low concentrations of these analytes. The HST system and column reduced peak tailing by 65-80% and peak width by 70-86% for LPA and PA. Moreover, increased signal intensities of up to 12.7 times were observed for LPA with the HST approach compared to the equivalent untreated LC system and column. The application of this methodology to the analysis of chicken egg PA and brain porcine PS extracts were accompanied by similar improvements in data quality. (c) 2022 Published by Elsevier B.V.
查看更多>>摘要：A nanostructure sponge-like porous manganese(II, III) oxide was synthesized and applied as a new fiber coating for solvent-assisted solid-phase microextraction. The synthesized material was characterized via Fourier-transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and N-2 adsorption/desorption techniques. To investigate the extraction performance of the prepared material, direct immersion solid-phase microextraction followed by gas chromatography-mass spectrometry was used for the determination of the selected polycyclic aromatic hydrocarbons in wastewater samples. Three polycyclic aromatic hydrocarbons including 1-methylnaphthalene, anthracene, and pyrene were selected as model analytes. To maximize the sensitivity of the method, key experimental factors affecting the extraction efficiency of the analytes such as ionic strength, extraction solvent, stirring rate, extraction temperature and time, and desorption temperature and time were optimized. The applicability of the new coating material for the extraction of the selected analytes from wastewater samples was evaluated. Under the optimum conditions, detection limits between 0.7 and 1.5 ng L-1 were obtained for the model analytes. The linear dynamic range was 5.0-3.0 x 10(3) ng L-1 for all the analytes. Relative standard deviations were between 2 and 11%. In the case of real sample analysis, the extraction recoveries of the analytes were obtained in the range of 77-111%. (c) 2022 Published by Elsevier B.V.
查看更多>>摘要：An highly sensitive, rapid and enantioselective method was developed for the enantioseparation and determination of citalopram enantiomers by cation selective exhaustive injection-sweeping-cyclodextrin modified electrokinetic chromatography (CSEI-sweeping-CDEKC). The optimized conditions were: 50 mM pH 3.0 phosphate solution with 25 mg.mL(-1) S-beta-CD used as background buffer, 50 mbar 300 s hydrodynamical injection of 150 mM pH 3.0 NaH2PO4 buffer followed with 5 s water plug, 10 kV 600 s electrokinetic sample injection,-20 kV CDEKC run. Under the optimized conditions, the resolution was Rs = 8.04, the enrichment factor as up to 2163 folds, the LOD values were: 3.6 ng.mL(-1) for R-citalopram, 4.1 ng.mL(-1) for S-citalopram, and 3 ng.mL(-1) for both enantiomers in plasma samples. This new method showed good precision, repeatability and stability, which had been successfully applied to the impurity inspection of escitalopram oxalate and the stereoselective pharmacokinetic study of citalopram enantiomers.(c) 2022 Elsevier B.V. All rights reserved.
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