During the last decades, the quality of aquatic ecosystems has been threatened by increasing levels of pollutions, caused by the discharge of man-made chemicals, both via accidental release of ...pollutants as well as a consequence of the constant outflow of inadequately treated wastewater effluents. For this reason, the European Union is updating its legislations with the aim of limiting the release of emerging contaminants. The Commission Implementing Decision (EU) 2015/495 published in March 2015 drafts a “Watch list” of compounds to be monitored Europe-wide. In this study, a methodology based on online solid-phase extraction (SPE) ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer (UHPLC-MS/MS) was developed for the simultaneous determination of the 17 compounds listed therein. The proposed method offers advantages over already available methods, such as versatility (all 17 compounds can be analyzed simultaneously), shorter time required for analysis, robustness, and sensitivity. The employment of online sample preparation minimized sample manipulation and reduced dramatically the sample volume needed and time required, dramatically the sample volume needed and time required, thus making the analysis fast and reliable. The method was successfully validated in surface water and influent and effluent wastewater. Limits of detection ranged from sub- to low-nanogram per liter levels, in compliance with the EU limits, with the only exception of EE2.
Graphical abstract
Schematic of the workflow for the analysis of the Watch list compounds.
Penindolone (PND) is a novel broad-spectrum anti-Influenza A Virus (IAV) agent blocking hemagglutinin-mediated adsorption and membrane fusion. The goal of this work was to reveal the metabolic route ...of PND in rats. Ultra-high-performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS) was used for metabolite identification in rat bile, feces and urine after administration of PND. A total of 25 metabolites, including 9 phase I metabolites and 16 phase II metabolites, were characterized. The metabolic pathways were proposed, and metabolites were visualized via Global Natural Product Social Molecular Networking (GNPS). It was found that 65.24-80.44% of the PND presented in the formation of glucuronide conjugate products in bile, and more than 51% of prototype was excreted through feces. In in vitro metabolism of PND by rat, mouse and human liver microsomes (LMs) system, PND was discovered to be eliminated in LMs to different extents with significant species differences. The effects of chemical inhibitors of isozymes on the metabolism of PND in vitro indicated that CYP2E1/2C9/3A4 and UGT1A1/1A6/1A9 were the metabolic enzymes responsible for PND metabolism. PND metabolism in vivo could be blocked by UGTs inhibitor (ibrutinib) to a certain extent. These findings provided a basis for further research and development of PND.
An approach for fabrication of graphene sponge (GS)-based solid-phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with ultraviolet detection (HPLC-UV) is proposed, ...which was applied to determine the six benzotriazole UV filters in water and cosmetic samples. Several extraction conditions including type of elution solvent, the volume of elution solvent, and salt effect were optimized. Under the optimum conditions, the GS-SPE-HPLC-UV method shows a low limit of detection (LOD, S/
N
= 3) of 0.02–0.08 μg L
−1
for standard solution, limits of quantification (LOQ, S/
N
= 10) of 0.07–0.26 μg L
−1
for standard solution, wide linear ranges from 20.0 to 1000 μg L
−1
for all compounds for standard solution, correlation coefficients (
r
) of more than 0.999, except for 2-(2′-hydroxy-5′-methylphenyl)benzotriazole (UV-P), and acceptable reproducibility (relative standard deviations, RSDs < 6.5% for intra-day, RSDs < 8.1% for inter-day). The satisfactory recoveries were obtained in the range 89–105% with RSDs lower than 9.8% at the three spiked levels of 20, 50, and 100 μg L
−1
. Every home-made GS-SPE cartridge can be reused for more than 60 cycles. The method is facile, low-cost, rapid, sensitive, and suitable for the determination of UV filters in water and cosmetics samples.
Graphical abstract
ᅟ
Dioscin in
Trigonella foenum-graecum
was purified by foam separation combined with preparative high-performance liquid chromatography (Prep-HPLC) and the preparation method of dioscin monomer was ...established. Then, the structure was confirmed by FI-IR, HRMS,
13
C-NMR and
1
H-NMR.The results showed that the method had the advantages of simple operation, short separation period and high efficiency and was suitable for the separation and preparation of dioscin from
Trigonella foenum-graecum
.
A novel cellulose derivative bearing bulky 4‐(2‐benzothienyl)phenylcarbamate substituents (Cel‐1) was readily synthesized by carbamoylation followed by Suzuki–Miyaura coupling reaction. The ...corresponding coated‐type chiral stationary phase (CSP) was prepared on basis of the derivative, and its chiral recognition ability was then evaluated by high‐performance liquid chromatography (HPLC). The chiral recognition ability of the cellulose derivative was greatly influenced by introduction of the bulky benzothienyl pendants on the aromatic moieties of phenylcarbamates, compared with its analog with smaller groups. Many racemates, including the metal tris(acetylacetonate) complexes, chiral drug, and the analyte with axial chirality, were sufficiently separated with good enantioselectivities on Cel‐1. Some of them were even higher than those on the commercially powerful Chiralcel OD, which is also a coated‐type CSP derived from cellulose phenylcarbamate derivative containing smaller 3,5‐dimethyl pendants. The 1H NMR and circular dichroism (CD) spectra of Cel‐1 indicated that the obtained derivative possessed a regular higher order structure, and a strong cotton effect was observed within the absorption range of π‐conjugated pendant at 350–500 nm. Impressively, the cellulose derivative bearing the bulky 4‐(2‐benzothienyl)phenylcarbamates exhibited good enantioselective fluorescence quenching behavior to the enantiomer pair of 1‐phenylethylamine, probably suggesting its potential for the application as a chiral fluorescent sensor with high efficiency. The combination of the arrangement of bulky π‐conjugated benzothienyl pendants on the phenylcarbamate moieties surrounding the helical backbone and the regular higher order structure of the polymer itself probably played a key role for this high chiral fluorescent recognition ability of Cel‐1. The interaction sites of bulky 4‐(2‐benzothienyl)phenylcarbamate pendants in its excited state can exhibit higher enantioselective discrimination via fluorescent response to the chiral compound Q1, whereas the chiral recognition ability of Cel‐1 to the same compound in the ground state had no clear improvement.
A novel cellulose derivative bearing bulky 4‐(2‐benzothienyl)phenylcarbamate substituents (Cel‐1) was readily synthesized, and its chiral recognition ability was evaluated by high‐performance liquid chromatography (HPLC). The chiral recognition ability of Cel‐1 was greatly influenced by introduction of bulky benzothienyl pendants on phenylcarbamate moieties. Many racemates were sufficiently separated with good enantioselectivities, and some of them were higher than those on commercial Chiralcel OD. Impressively, Cel‐1 exhibited good enantioselective fluorescence quenching behavior to enantiomer pair of 1‐phenylethylamine.
Dyslipidemia is important because of its association with various metabolic complications. Numerous studies have sought to obtain scientific evidence for managing dyslipidemia patients.
This study ...aims to identify differences in the nutritional traits of dyslipidemia subjects based on metabolite patterns.
Dyslipidemia (n = 73) and control (n = 80) subjects were included. Dyslipidemia was defined as triglycerides ≥200 mg/dL, total cholesterol ≥240 mg/dL, low density lipoprotein cholesterol ≥160 mg/dL, high-density lipoprotein cholesterol <40 mg/dL (men) or 50 mg/dL (women), or lipid-lowering medicine use. Nontargeted metabolomics based on ultra-high performance liquid chromatography–mass spectrometry identified plasma metabolites, and K-means clustering was used to reconstitute groups based on the similarity of metabolomic patterns across all subjects. Then, with eXtreme Gradient Boosting, metabolites significantly contributing to the new grouping were selected. Statistical analysis was conducted to analyze traits demonstrating appreciable differences between the groups.
Dyslipidemia subjects were divided into 2 groups based on whether they were (n = 24) or were not (n = 56) in a similar metabolic state as the controls by K-means clustering. The considerable contribution of 4 metabolites (3-hydroxybutyrylcarnitine, 2-octenal, 1,3,5-heptatriene, and 5β-cholanic acid) to this new subset of dyslipidemia was confirmed by eXtreme Gradient Boosting. Furthermore, fiber intake was significantly higher in dyslipidemia subjects whose metabolic state was similar to that of the control than in the dissimilar group (P = 0.002). Moreover, significant correlations were observed between the 4 metabolites and fiber intake. Regression analysis determined that the ideal cutoff for fiber intake was 17.28 g/d.
Dyslipidemia patients who consume 17.28 g/d or more of dietary fiber may maintain similar metabolic patterns to healthy individuals, with substantial effects on the changes in the concentrations of 4 metabolites. Our findings could be applied to developing dietary guidelines for dyslipidemia patients.
Enantiomers show different behaviors in interaction with the chiral environment. Due to their identical chemical structure and their wide application in various industries, such as agriculture, ...medicine, pesticide, food, and so forth, their separation is of great importance. Today, the term “nano” is frequently encountered in all fields. Technology and measuring devices are moving towards miniaturization, and the usage of nanomaterials in all sectors is expanding substantially. Given that scientists have recently attempted to apply miniaturized techniques known as nano‐liquid chromatography/capillary‐liquid chromatography, which were originally accomplished in 1988, as well as the widespread usage of nanomaterials for chiral resolution (back in 1989), this comprehensive study was developed. Searching the terms “nano” and “enantiomer separation” on scientific websites such as Scopus, Google Scholar, and Web of Science yields articles that either use miniaturized instruments or apply nanomaterials as chiral selectors with a variety of chemical and electrochemical detection techniques, which are discussed in this article.
Due to variation in instrument response caused by various sources of errors throughout an analytical assay, data normalization plays an indispensable role in untargeted LC-MS profiling, yet limited ...accepted guidelines on this topic exist. In this work, a systematic comparison of several normalization techniques, mainly focusing on internal standard-based approaches, has been performed to derive some general recommendations. For generation of untargeted lipidomic data, a comprehensive ultra-high performance liquid chromatography (UHPLC)-electrospray ionization (ESI)-quadrupole time of flight (QTOF)-MS/MS method was utilized. To monitor instrument stability and evaluate normalization performance, quality control (QC) samples, prepared from aliquots of all experimental samples, were embedded in the sequence. Stable isotope labeled standards, representing differing lipid classes, were spiked to each sample as internal standards for postacquisition normalization. Various metrics were used to compare distinct normalization strategies, with reduction of variation in QC samples being the critical requirement for acceptance of successful normalization. The comparison of intragroup coefficients of variation (CVs), median absolute deviations (MADs), and variance enables simple selection of the best performance of normalization with improved and coherent results. Furthermore, the importance for normalization in critical data sets, showing only minor effects between groups with high variation and outliers, is pointed out. Apart from normalization, also, influences of used raw data types are demonstrated. In addition, effects of various factors throughout the processing workflow were investigated and optimized. Eventually, implementation of quality control samples, even if not required for normalization, provided a useful basis for assessing data quality. Due to lack of consensus for selecting optimum normalization, suggestions for validating data integrity are given.
The current practices regarding the procurement chain of forest industry sidestreams, such as conifer bark, do not always lead to optimal conditions for preserving individual chemical compounds. This ...study investigates the standard way of storing bark in large piles in an open area. We mainly focus on the degradation of the most essential hydrophilic and hydrophobic extractives and carbohydrates. First, two large 450 m
piles of bark from Norway spruce (
) were formed, one of which was covered with snow. The degradation of the bark extractives was monitored for 24 weeks. Samples were taken from the middle, side and top of the pile. Each sample was extracted at 120 °C with both
-hexane and water, and the extracts produced were then analysed chromatographically using gas chromatography with flame ionisation or mass selective detection and high-performance liquid chromatography. The carbohydrates were next analysed using acidic hydrolysis and acidic methanolysis, followed by chromatographic separation of the monosaccharides formed and their derivatives. The results showed that the most intensive degradation occurred during the first 4 weeks of storage. The levels of hydrophilic extractives were also found to decrease drastically (69% in normal pile and 73% in snow-covered pile) during storage, whereas the decrease in hydrophobic extractives was relatively stable (15% in normal pile and 8% in snow-covered pile). The top of the piles exhibited the most significant decrease in the total level of extractives (73% in normal and snow-covered pile), whereas the bark in the middle of the pile retained the highest amount of extractives (decreased by 51% in normal pile and 47% in snow-covered pile) after 24-week storage.
Efficient biosurfactant producers with hydrocarbon degradation capability and harsh environment adaptability are precious bioresources for microbial enhanced oil recovery and petroleum-related ...bioremediation. In this study, a novel facultative-halophilic strain Bacillus sp. XT-2 was isolated and shown to degrade long-chain hydrocarbons along with lipopeptide biosurfactants production. The biosurfactants exhibited remarkable surface activity and emulsification ability against different hydrocarbons with emulsification index of 73%–87%. High performance liquid chromatography-mass spectrometry (HPLC-MS) method combined with genome sequencing was used to identify the lipopeptide biosurfactants and their corresponding synthetic gene clusters. The results showed that the lipopeptides could be classified to the isoforms and homologs of bacillibactin, fengycin, and surfactin, and strain XT-2 possessed their entire core synthetic genes. Artificial core-flooding experiments demonstrated both cultures of XT-2 and its biosurfactant could significantly increase the oil recovery by 13.43%–25.01%. These findings indicate the novel strain XT-2 and its lipopeptides have great potentials in environmental remediation and petroleum development.
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•A novel facultative-halophilic strain XT-2 was isolated from oil reservoir.•The strain can convert long chain n-alkanes to lipopeptide biosurfactants.•Gene clusters responded for the biosurfactants synthesis were identified.•The biosurfactants with various structures show great oil emulsification ability.•Strain XT-2 and its biosurfactant enhanced 13.43%–25.01% of waxy oil recovery.
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