Liquid Chromatography Orbitrap High-resolution Mass Research Articles

Untargeted metabolomics profiling of tropical marine microalgae in batch culture system with different mobile phase using Liquid Chromatography-Orbitrap High-resolution Mass Spectrometry combined with chemometrics

Microalgae have recently been identified as a valuable source of natural bioactive compounds, with potential applications suggested in areas such as food, animal feed, energy production (biofuels), fine chemicals, and pharmaceuticals. However, their chemical diversity remains largely unexplored and it is necessary to determine their potency for further application. This study will explore the diversity of chemical compound from six tropical marine microalgae with untargeted comparative metabolomics approach using a Liquid Chromatography-Orbitrap High Resolution Mass Spectrometry with different mobile phases. Six microalgae species were isolated from Jakarta Bay, Indonesia. Species identification was carried out using morphological and molecular identification. The isolates Chlorella vulgaris InaCC M205 (C5), Chlorella sp. 12 (C12), Tetraselmis subcordiformis InaCC M206 (T2), Tetraselmis sp. 5 (T5), Nannochloropsis oceanica InaCC 207 (N4), and Porphyridium purpureum (P) were then cultivated using f/2 media in 1 L glass photobioreactors, irradiated with daylight lamps (4000 lux) under a 12 h/12 h photoperiod at 25 0C for until cultures reached the stationary phase. Biomass harvesting and measurements were carried out at the end of the culture period. The freeze-dry biomass then was analyzed using liquid chromatography-high resolution mass spectrometry. The results showed that biomass production on day 12 was not significantly different. Biomass production ranged from 0.8 to 1 g/L, with the highest production obtained from the C5 strain and the lowest from the C12 strain. Chromatography analysis revealed that untargeted metabolomics profiling of microalgae, using water-acetonitrile as mobile phase, identified potential compound markers such as N-Methyl-2-pyrrolidone, l-(+)-Cysteine, TBHQ and L-Phenylalanine, which can differentiate between species. Compound such as Cyromazine, Arachidic acid and 13(S)-HOTrE were the potential compound markers when using Water-Methanol as mobile phase. Our research indicates that the metabolomic profile of microalgae can be used to differentiate species depending on the choice of mobile phase.

Revealing the sterilization impact on paprika fingerprint: Key markers identified using untargeted metabolomics by liquid chromatography-Orbitrap high-resolution mass spectrometry

Paprika (Capsicum annuum L.) is a popular spice known for its unique properties. Spices are susceptible to microbiological risks arising from harvest factors such as high moisture or environmental contamination. To ensure microbiological safety, post-harvest processing based on heat sterilization, free of chemicals and radiation, is becoming essential in the European market. This study introduces a novel metabolomics approach using ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole-Orbitrap-high-resolution mass spectrometry (HRMS) to assess the sterilization impact on paprika's metabolomic composition. Sterilized and untreated samples were distinguished by OPLS-DA, achieving perfect predictability with high-quality parameters (R2Y = 0.988, Q2 = 0.904). The methodology identified 19 key markers, including fatty acids, amino acids, etc. Sterilization reduced fatty acids such as linoleic acid but increased other metabolites such as DL-malic acid and flazin. This research introduces new metabolomics strategies to ensure paprika quality and other valuable spices, focusing on unexplored sterilization processes.

Exploring the mechanisms of Huangqin Qingfei Decoction on acute lung injury by LC-MS combined network pharmacology analysis

BackgroundAcute lung injury (ALI) is a respiratory disease characterized by pulmonary inflammation and increased microvascular permeability, resulting in significant mortality and a lack of effective pharmacological treatment. Huangqin Qingfei Decoction (HQQFD), a Traditional Chinese Medicine (TCM) prescription known for its heat-clearing and detoxifying properties, has shown efficacy in treating ALI. However, the underlying mechanisms of HQQFD to against ALI remain to be elucidated. PurposeThis study aims to discover the mechanisms and the principal bioactive compounds contributing to HQQFD's protective effects in the treatment of ALI. MethodsAn ultra-high performance liquid chromatography-Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) method was employed to characterize the chemical profile in HQQFD and xenobiotics (prototypes and metabolites) in rat lung tissue. Based on prototypes identified, a symptom-guided pharmacological networks of ALI were performed. Molecular docking and extensive literature reviews were conducted to validate our findings. ResultsA total of 105 compounds were identified in HQQFD, and a total of 194 HQQFD-related xenobiotics (30 prototypes and 163 metabolites) were detected in rat lung tissue. Based on prototypes identified in rat lung, a symptom-guided pharmacological networks of ALI were constructed, AKT1, TNF, EGFR, MMP2, GSK3B, STAT3, MAPK8, IL-6, CDK2 and TP53 were finally identified as key targets. Subsequently, 11 compounds with protective and therapeutic activity were selected by molecular docking analysis, including genipin 1-gentiobioside, chrysin-6-C-α-L-arabinoside-8-C-β-d-glucoside, scutellarin, chrysin-6-C-β-d-glucoside-8-C-α-L-arabinoside, 6’’-O-[(E)-p-coumaroyl] genipin-gentiobioside, apigenin 7-O-glucoside, baicalin, dihydrobaicalin, wogonoside, crocin I, crocetin. Bioinformatics and literature analysis suggested that, baicalin, wogonoside, genipin 1-gentiobioside and crocetin may be the primary active compounds of HQQFD, potentially targeting GSK3B, MAPK8, IL-6, AKT1 and TNF for HQQFD in addressing ALI. The therapeutic effects of HQQFD may be mediated through the IL-17 and PI3K-AKT signaling pathways. ConclusionThe predominant components of HQQFD against ALI are baicalein, wogonoside, genipin 1-gentiobiosid and crocetin, with the IL-17 and PI3K-AKT pathways playing crucial roles. This study provides a foundational guide for future research and introduces innovative methods for exploring the mechanisms of other drug combinations or TCM formulas.

Alkali hydrolysis of wool fibres using microwave irradiation as a recycling approach for handling wool-waste

The aim of the present work is to investigate the influence of microwave irradiation on alkali hydrolysis, under various thermochemical conditions, of wool fibres. This perspective seems to be a promising alternative for the valorization of wool waste. The reaction yield is calculated in every case in order to determine the optimum hydrolysis conditions. The solid residue, as well as the filtrate, are subjected to instrumental chemical analysis in order to identify and isolate useful products. The optimal conditions for the hydrolysis of wool resulted to be the use of 5% w/v NaOH, microwave treatment for 10 min in absence of phase-transfer catalyst. In addition, the analysis in the Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) allowed the identification of certain small molecules like N2, H2S, NH3, C6H5OH, C4H9NO and larger ones like amino acids, such as alanine, cystine, proline, valine and leucine. Additionally, the content of wool hydrolysate was specified upon identifying several substituted products of tyrosine, proline and alanine amino acids. Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry (LC–Orbitrap HRMS) was also employed to identify the components present in the wool hydrolysate, detecting mainly various dipeptides as well as leucylproline and cysteic acid. In this light, the amino acids produced by wool alkali hydrolysis degradation could valorise the wool waste once inserted in industrial chemistry, as a prominent alternative for “greener” adhesives of two components, outlining by these means the feasibility of a practically sustainable circular economy.

Lipidomics Analysis of Different Marine Fish Oils Using Untargeted Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry and Chemometrics

Lipidomics Analysis of Different Marine Fish Oils Using Untargeted Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry and Chemometrics

Synthesis and evaluation of a chitosan nanomaterial as efficient sorbent for determination of fungicide residues in waters and wine by liquid chromatography high resolution mass spectrometry.

In the present study a novel, cost-effective, environmentally friendly, and efficient analytical method was developed to analyze fungicide residues in water and wine. The method relies on the application of a newly developed sorbent nanomaterial named Nano-Cs-NAT, synthesized by modifying chitosan, a naturally occurring, low-cost polysaccharide, through grafting with two acrylic monomers and a cross-linker. Nano-Cs-NAT was introduced as analytical sorbent for Dispersive Micro Solid Phase Extraction (D-μ-SPE) before Liquid Chromatography-Orbitrap High-Resolution Mass Spectrometry (LC-Orbitrap HRMS) analysis of twelve fungicides commonly used in viticulture (among the others, triazoles, strobilurines and N-substituted imidazoles). Characterization of the sorbent was conducted, confirming the successful acrylation of chitosan. A multivariate approach was employed to optimize D-μ-SPE extraction parameters. The material was found to be highly effective in simultaneously purifying and concentrating the target analytes, enhancing overall analytical efficiency and sensitivity. The Nano-Cs-NAT-D-μ-SPE-LC-Orbitrap-HRMS method was thoroughly validated, exhibiting good recoveries (72-104%), reproducibility (average RSD ≤ 6%) and repeatability (average RSD ≤ 7%). It also achieved low limits of detection (LOD) in river water (average LOD of 0.04 μg L-1) and wine (average LOD of 0.72 μg kg-1), highlighting its potential for routine fungicide residue analysis. This developed method addresses environmental and food safety concerns by providing an efficient solution for detecting fungicide residues in waters and wine.

Determination of Pesticide Residues in Olive Oil Using QuEChERS Extraction and Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry: Comparison of Different Clean-Up Sorbents and Validation Study

The aim of this study was the optimization of the clean–up step in the widely applied QuEChERS method for the determination of 39 representative multiclass pesticides in olive oil with Ultra-High-Performance Chromatography–Orbitrap Mass Spectrometry (UHPLC-Orbitrap-MS). The analytical methodology combines the original version of QuEChERS extraction with two different clean-up-step approaches, using firstly a combination of Z-Sep+, PSA and MgSO4 and secondly EMR-lipid. The methods were compared for their efficiency in the removal of fats and co-extractives and their effect on the analytical performance characteristics. Both methods were evaluated in terms of linearity, matrix effects (ME), recovery, precision, limits of detection (LOD) and quantification (LOQ) and expanded uncertainty in three spiking levels of 30, 100 and 300 μg/kg. The recoveries ranged between 70–113% for 95% of analytes (RSDr < 14%) when EMR-lipid was used as a sorbent, while in the case of Z-Sep+/PSA/MgSO4 recoveries ranged between 72–107% for 92% of analytes (RSDr < 18%). ME showed low signal suppression for 77% of analytes in the case of Z-Sep+/PSA/MgSO4 and for 85% of analytes in the case of EMR-lipid. According to the results, both methodologies provided good analytical performances fulfilling validation criteria; however, the EMR-lipid sorbent showed better clean-up capacity (i.e., less matrix effects and lower variability in extraction recoveries) and validation parameter values for more analytes. The validated method was successfully applied to 30 olive oil samples from different regions of Greece. No residues have been identified in the analyzed samples.

Overlooked Contribution of the Indole Moiety to the Formation of Haloacetonitrile Disinfection Byproducts

Haloacetonitriles (HANs) are a group of disinfection byproducts with high toxicity and frequent occurrence. Past studies have focused on the free amine groups, especially those in amino acids, as HAN precursors. This study reports, for the first time, that the indole moiety such as that in the tryptophan side chain is also a potent precursor for the most common HANs dichloroacetonitrile, bromochloroacetonitrile, and dibromoacetonitrile. 3-Indolepropionic acid, differing from tryptophan only in the absence of the free amine group, formed HANs at levels 57-76% of those by tryptophan at a halogen/nitrogen molar ratio of 10. Experiments with tryptophan-(amino-15N) showed that the indole contributed to 28-51% of the HANs formed by tryptophan. At low oxidant excess (e.g., halogen/precursor = 5), 3-indolepropionic acid even formed more HANs than Trp by 3.5-, 2.5-, and 1.8-fold during free chlorination, free bromination, and chlorination in the presence of bromide (0.6 mg/L), respectively. Indole's HAN formation pathway was investigated by exploring the chlorination/bromination products of 3-indolepropionic acid using liquid chromatography-orbitrap high-resolution mass spectrometry. A total of 22 intermediates were detected, including pyrrole ring-opening products with an N-formyl group, 2-substituted anilines with different hydroxyl/halogen substitutions, and an intermediate with a postulated non-aromatic ring structure.

Electrospun fluorinated carbon nanotubes/silk fibroin composite nanofibers for the analysis of perfluoroalkyl and polyfluoroalkyl substances

Assessment of the exposure risk of perfluoroalkyl and polyfluoroalkyl substances (PFASs) has been of public concern for many years. However, it is a challenging undertaking because of the trace levels of these contaminants in the environment and biological systems. In this work, fluorinated carbon nanotubes/silk fibroin (F-CNTs/SF) nanofibers were for the first time synthesized by electrospinning and evaluated as a new adsorbent in pipette tip-solid-phase extraction to enrich PFASs. The addition of F-CNTs increased the mechanical strength and toughness of the SF nanofibers, thus improving the durability of composite nanofibers. The proteophilicity of silk fibroin formed the basis of the good affinity of this material with PFASs. The adsorption behaviors of PFASs on the F-CNTs/SF were investigated by adsorption isotherm experiments to understand the mechanism of extraction. With analysis using ultrahigh performance liquid chromatography-Orbitrap high-resolution mass spectrometric, low limits of detection (0.006–0.090 μg L−1) and enrichment factors of 13–48 were obtained. Meanwhile, the developed method was successfully applied to the detection of wastewater and human placenta samples. This work provides a new idea for the design of novel adsorbents with proteins integrated in polymer nanostructures, a potential routine and practical monitoring technique for PFASs in environmental and biological samples.

Photocatalytic Degradation of Psychiatric Pharmaceuticals in Hospital WWTP Secondary Effluents Using g-C3N4 and g-C3N4/MoS2 Catalysts in Laboratory-Scale Pilot

Today, the pollution caused by a multitude of pharmaceuticals used by humans has been recognized as a major environmental problem. The objective of this study was to evaluate and compare the photocatalytic degradation of ten target psychiatric drugs in hospital wastewater effluents using g-C3N4 and 1%MoS2/g-C3N4 (1MSCN) as photocatalytic materials. The experiments were performed using real wastewater samples collected from hospital wastewater treatment plant (WWTP) secondary effluent in spiked and inherent pharmaceutical concentration levels. The photocatalytic experiments were performed in a laboratory-scale pilot plant composed of a stainless-steel lamp reactor (46 L) equipped with ten UVA lamps and quartz filters connected in series with a polypropylene recirculation tank (55–100 L). In addition, experiments were carried out in a solar simulator apparatus Atlas Suntest XLS+ at a 500 Wm−2 irradiation intensity. The analysis of the samples was accomplished by solid-phase extraction, followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. Results showed that the photocatalytic degradation of pharmaceutical compounds followed first-order kinetics. In all cases, 1MSCN presented higher photocatalytic performance than g-C3N4. The removal rates of the pharmaceutical compounds were determined above 30% and 54% using g-C3N4 and 1MSCN, respectively. Parallel to kinetic studies, the transformation products (TPs) generated during the treatment were investigated.

QuEChERS-based extraction and two-dimensional liquid chromatography-high resolution mass spectrometry for the determination of long chain chlorinated paraffins in sediments

In this study, a method was established for the analysis of long-chain chlorinated paraffins (LCCPs) in sediment based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and two-dimensional liquid chromatography-Orbitrap high resolution mass spectrometry (2DLCOrbitrap HRMS). Compared with other reported methods, this method greatly reduces sample preparation time (2 h) and solvent consumption. The QuEChERS extraction method presented satisfactory recoveries, 90.5–95.2, 84.7–86.6, and 81.4–83.4% of 5, 50, and 200 ng/g LCCPs with 49% Cl spiked into sediments. Meanwhile, no matrix effects were found in the LCCPs analysis after online purification by the 2DLC system. With the current commercial LCCP standards and a mixture of three chlorinated paraffins (CPs) industrial products, a suspect screening strategy was established and accurate identification of LCCPs (including vLCCPs, which carbon chain length greater than 20) under the plight that the reference standards for vLCCPs are currently unavailable. A total of 21 C18–20-LCCP and 22 vLCCP congeners were identified in sediment samples collected from Dongting Lake, China. The total concentrations of LCCPs in six sediment samples ranged from 1.69 to 18.0 ng/g (median 6.66 ng/g) and was dominated by C18 groups (mean, 28.8%), C19 groups (mean, 19.1%) and C21 groups (mean, 16.9%). Taken together, the successful application of this method to analyze sediment samples shows great potential for the analysis of LCCPs in environmental samples in future studies.

Solar photocatalytic degradation of inherent pharmaceutical residues in real hospital WWTP effluents using titanium dioxide on a CPC pilot scale reactor

Hospital wastewaters (HWW) contain a complex mixture of pharmaceutical compounds that cannot be removed by conventional treatment processes. This study reports on the degradation of Pharmaceutical Active Compounds (PhACs) in hospital wastewater treatment plant (WWTP) secondary effluents using TiO2 and solar compound parabolic collector pilot plant. Inherent concentration loadings of pharmaceuticals in secondary wastewater were photocatalytically treated in a ‘’real-world’’ approach. Among the detected pharmaceuticals, amisulpride, venlafaxine and metabolite O-desmethyl venlafaxine, citalopram and carbamazepine occurred in all experimental runs. The analysis of the samples before and after the photocatalytic treatment was accomplished by solid phase extraction, followed by liquid chromatography-Orbitrap high-resolution mass spectrometry. Results showed that photocatalytic degradation of PhAcs followed first order kinetics. Catalyst loadings higher between 150 mgL−1 resulted in removal percentages higher than 73% with accumulative energy c.a. > 25 kJL−1 depending on the initial wastewater characteristics. For 200 mgL−1 catalyst loading pharmaceutical removal rate constants ranged between 0.018 and 0.039 LkJ−1 recorded for citalopram and venlafaxine, respectively. Photocatalytic treatment resulted also in the amelioration of the effluent quality physicochemical characteristics i.e. COD, BOD as well of the biodegradability index. The catalyst reusability was studied without any treatment for three consecutive cycles showing a significant efficiency decrease mainly between the first and the second cycle i.e. from 21% to 80% in the respective reaction constants. Finally, the effluent toxicity before and during the photocatalytic treatment was evaluated by Vibrio fischeri bioassay revealing that toxicity is sharply decreased leading to non-toxicity in the final treated effluents. Further studies on TiO2 photocatalytic applications should focus on the separation and regeneration of catalyst.

Characterization and identification of the metabolites of dihydromethysticin by ultra-high-performance liquid chromatography orbitrap high-resolution mass spectrometry.

Dihydromethysticin, a natural component from Piper methysticum Forst, has been reported to display pharmacological effects in mental disorders and some malignant tumors. However, the metabolism of this component remained unknown. The goal of this work was conducted to discover the metabolic profiles of dihydromethysticin. The in vitro incubation was performed by incubating dihydromethysticin with rat, monkey, and human liver microsomes and hepatocytes. An analytical assay of ultra-high performance liquid chromatography combined with Orbitrap high-resolution mass spectrometry was utilized to detect and identify the metabolites. With high resolution mass spectrometric determination, the accurate mass, elemental composition, and product ions of the metabolites were determined, which enabled structural characterization to become easy. Under the present conditions, four phase-I metabolites, as well as six phase-II metabolites, were detected and their tentative structures were characterized by mass spectra. M4 was found as the most abundant metabolite both in liver microsomes and hepatocytes. Cytochrome P450 1A2, 2C9, and 3A4 contributed to the formation of this metabolite by using human recombinant P450 enzymes. M4 can be oxidized into reactive ortho-quinone intermediate followed by conjugating with glutathione. M4 was also subject to glucuronidation (M1 and M2) and methylation (M5). Demethylenation, oxidation, hydroxylation, glucuronidation, glutathionylation, and methylation were the primary metabolic pathways of dihydromethysticin. This study provides in vitro metabolism data of dihydromethysticin, which is indispensable for understanding the disposition of this compound.

Ultra-high performance liquid chromatography-orbitrap high-resolution mass spectrometry for rapid screening and identification of 32 illegally added drugs in slimming and anti-impotence health foods

建立了基于超高效液相色谱-Orbitrap高分辨质谱的快速筛查及确证减肥和壮阳类保健食品中32种非法添加药物的分析方法,并总结了数据库建立和应用的相关要点。研究对象聚焦于非法添加药物的衍生物,在对比正负离子模式下各化合物响应强度的基础上建立了高分辨质谱信息库,对提取溶剂、色谱柱温度等实验条件进行了详细探究,尽可能给出了较宽的标准曲线线性范围。使用Hypersil gold vanquish色谱柱(100 mm×2.1 mm, 1.9 μm),梯度洗脱,流量0.3 mL/min,正、负离子全扫描/数据依赖的二级扫描模式,在17 min内完成32种目标化合物的数据采集,通过TraceFinder软件进行快速定性筛查和定量。结果显示在17 min内32种化合物能得到较好分离;2种基质加标溶液中32种化合物的一级质谱离子精确质量数的实测值与理论值均在5×10-6误差之内,二级碎片离子质量数的实测值与理论值均在1×10-5误差之内;方法学验证结果表明,所有化合物均显示出优异的线性关系,相关系数(r2)均大于0.99;固体基质中除达泊西汀、羟基硫代豪莫西地那非、硫代豪莫西地那非、硫代西地那非、去甲基硫代西地那非的回收率较低外,其余27种化合物的回收率为50.5%~84.5%,相对标准偏差(RSD)为1.2%~13%,液体基质中32种化合物的回收率范围为60.4%~109.3%, RSD为0.77%~8.2%;在48份减肥及壮阳类保健食品中检出1份阳性样品,检出率2.08%。该方法操作简单,结果定性准确,可用于减肥及壮阳类保健食品中32种非法添加药物的快速筛查及确证。

High-resolution mass spectrometry-based strategies for the target analysis and suspect screening of per- and polyfluoroalkyl substances in aqueous matrices

Per- and polyfluoroalkyl substances (PFASs) are a man-made diverse group of highly fluorinated aliphatic molecules, entailing risks to the ecosystems and human health. Herein, a streamlined, single-shot, HRMS-based analytical workflow for the quantitation and suspect screening of various PFAS was developed. Sample preparation was based on weak-anion exchange solid phase extraction, while instrumental analysis was performed by highly sensitive liquid chromatography Orbitrap–high-resolution mass spectrometry. The target method was optimized and validated for drinking water, surface water, and wastewater, while it was also modified to be efficient for leachates. Method performance was excellent in terms of linearity (R2 > 0.99), detection/quantification limits (reaching even at pg L−1 scale), recoveries (70–108 %, for most of the compounds), and precision (<20%). Isotopically labelled internal standards and matrix-matched calibration curves were used for quantification. The suspect analysis performed on a single-stage HRMS method operating in data-dependent ‘discovery’ mode. Thus, content-rich spectra were acquired and once combined with suspect screening features such as peak picking, feature alignment, and compound annotation enabled the putative annotation of the tested PFAS with high confidence. After evaluation, the presented fully elaborated workflow was applied to real samples to explore the putative annotation of the tested PFAS with high confidence for the first time in Greece for five different matrices, revealing maximum concentrations for PFOS 1.5 ng L−1 in tap water and 394.4 ng L−1 in effluent wastewater, and PFHxA 4284.8 ng L−1 in leachates.

Untargeted metabolomics and proteomics approach using liquid chromatography-Orbitrap high resolution mass spectrometry to detect pork adulteration in Pangasius hypopthalmus meat

Pangasius hypopthalmus is well known as a good source of protein. However, Pangasius hypopthalmus meat (PHM) can be adulterated with pork for economic concern, thus, analytical methods for authentication are required. Untargeted metabolomics and proteomics using liquid chromatography-high resolution mass spectrometry (LC-HRMS) and chemometrics of principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) was successfully used to differentiate authentic and adulterated PHM with the good of fitness (R > 0.95) and good of predictivity (Q > 0.5). Metabolites of PC(o-18:0/18:2(9Z,12Z)) was found to be a potential marker for pork whereas DMPC (dimyristoylphosphatidylcholine) was a potential marker for PHM. Meanwhile, pork peptide marker of myoglobin (HPGDFGADAQGAMSK) and β-hemoglobin (FFESFGDLSNADAVMGNPK) could be identified. Both metabolomics and proteomics using LC-HRMS could detect pork at the lowest concentration level (0.5% w/w). In conclusion, untargeted metabolomics and proteomics using LC-HRMS in combination with chemometrics could be used as powerful methods to detect pork adulteration in fish meat.

Development and validation of an UHPLC-Orbitrap-HRMS method for rapid determination of endogenous L-carnitine in patients on hemodialysis/peritoneal dialysis and its application to promote rational drug use.

BackgroundL-carnitine is an endogenous vitamin-like amino acid derivate which plays an essential role in energy metabolism and can be easily lost via dialysis. Deficiency of L-carnitine has great effects on many aspects of bodily functions. To determine the deficiency degree and adjust the supplementation dose, a rapid, sensitive, and specific method for the detection of endogenous L-carnitine in the plasma of dialysis patients using ultra-high performance liquid chromatography-Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-HRMS) was developed and validated.MethodsThe plasma samples were processed by protein precipitation and centrifugation before analysis using UHPLC-Orbitrap-HRMS. Sample separation was achieved with a hydrophilic interaction liquid chromatography (HILIC) column, using an isocratic elution with a runtime of 5 min. The separated analytes were detected by positive ionization mode in full scan mode and targeted-single ion monitoring (t-SIM) mode. Mildronate was used as the internal standard (IS).ResultsAll the plasma could be detected in the range of 6.169 to 197.394 µM, with adequate accuracy, precision, and recovery. The method was validated in fortified validation with relative standard deviations (RSD) 5.15–8.74%. This method was applied to the analysis of 105 dialysis patients and 39 healthy participants, the results revealed that peritoneal dialysis patients without L-carnitine supplementation should pay more attention to L-carnitine monitoring, meanwhile, all the hemodialysis patients were advised to be routinely given a full dose of L-carnitine, no matter whether they had taken L-carnitine or not.ConclusionsThis study developed a simple and rapid UHPLC-Orbitrap-HRMS method for detection of endogenous L-carnitine in dialysis patients, which could be useful to promote rational drug use.

Assessment of a wide array of organic micropollutants of emerging concern in wastewater treatment plants in Greece: Occurrence, removals, mass loading and potential risks

Exploring the contamination profile of multi-class emerging contaminants (ECs) in wastewater is highly desirable. To this end, the occurrence, removal, mass loading and risks associated with a large panel of pharmaceuticals and personal care products, illicit drugs, perfluorinated compounds and organophosphate flame retardants in two wastewater treatment plants (WWTPs) in the region of Thessaloniki (Greece) after a survey is illustrated. Influent and effluent wastewaters were submitted to solid phase extraction on Oasis HLB cartridges, followed by ultra-high-performance liquid chromatography Orbitrap high-resolution mass spectrometry (UHPLC–Orbitrap MS). Influent concentrations in both WWTPs were notably higher than effluent, with caffeine, acetaminophen, irbesartan and valsartan being the most ubiquitous compounds, exhibiting elevated concentrations. Average effluent concentrations ranged from below the method quantification limits (<MQL) to remarkably high values (μg L−1 scale), such as for caffeine, acetaminophen, diclofenac, irbesartan and valsartan, among others. Removal efficiencies ranged between −273% for lamotrigine and 100%, i.e., for the UV filter BP1. Notably, the polar compounds such as cytarabine, methotrexate and capecitabine were removed at a rate >80% in both WWTPs, allowing the correlation between logKow and removals. Interesting trends for the illicit drugs were revealed by means of mass loading estimation, as in the case of benzoylecgonine (71.6 mg/day/1000 inhabitants). Ecotoxicological risk assessment was evaluated for both single components and mixture, using three approaches: risk quotient (RQ), risk quotient considering frequency (RQf) and toxic units (TU). Irbesartan and telmisartan posed a high risk in all trophic levels, while fish was the most sensitive taxa for diclofenac. This work aspires to intensify the surveillance programs for the receiving water bodies, as well as to motivate the investigation of toxicity to non-target organisms.

Unraveling the origin of aged varnishes for the proper restoration of old paintings using spectroscopic and spectrometric techniques

This study deals with the investigation of old varnishes from six paintings belonging to the collection of the “Teloglion Foundation of Arts”, Aristotle University of Thessaloniki in Greece employing three complementary analytical techniques. The purpose of this research was to identify the origin of the protective layers of the varnishes with the ultimate goal of their safe removal during their treatment. To identify the components of the varnishes, sampling was carried out in both a mechanical and chemical way from selected areas of all the works of art. The samples were firstly studied with Fourier-Transform Infrared Spectroscopy (FT-IR), secondly with Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC–MS), and finally with Liquid Chromatography–Orbitrap High-Resolution Mass Spectrometry (LC–Orbitrap HRMS). The application of these methods led not only to the verification of the compounds of the varnishes, but also to the presence of specific fatty acids included in the drying oils, as well as diterpene and triterpene resins. FT-IR spectra were very similar to those corresponding to natural resins, while Py-GC–MS evidenced the fatty acids profile in drying oils as well as the presence of dammarane skeleton among others. The main findings from LC–Orbitrap MS/MS included drying and essential oils, mastic, and dammar. Based on the obtained results, a solubility study of varnishes was also performed. The appropriate mixture of solvents for the coating varnishes removal was investigated with the aid of the Teas solubility triangle and the most suitable solvent mixture for the proper restoration was proposed. A conservation effort for one painting was carried out successfully, confirming the applicability of the method.

Analysis of chemical variations between raw and wine-processed Ligustri Lucidi Fructus by ultra-high-performance liquid chromatography-Q-Exactive Orbitrap/MS combined with multivariate statistical analysis approach.

Ligustri Lucidi Fructus (LLF) is the dried and mature fruit of Ligubtrum lucidum Ait., which has the effect of nourishing the liver and kidney, brightening the eyes and promoting the growth of black hair. Wine-processed LLF is commonly used in traditional Chinese medicine; however, the processing mechanisms are still unclear. Herein, a system data acquisition and mining strategy was designed to investigate the chemical profile differences between the raw and wine-processed LLF, based on high-performance liquid chromatography-Orbitrap high resolution mass spectrometry coupled with multivariate statistical analysis including principal component analysis and partial least square analysis. Afterwars, a total of 55 components were found to be the main contributors to the significant difference between raw and wine-processed LLF by comparison with chromatographic behaviors, intact precursor ions, and characteristic MS fragmentation patterns. In addition, 10 main constituents of raw and wine-processed LLF were simultaneously determined by UHPLC-MS/MS for analyzing the content variations. Some structural transformation mechanisms during wine processing were deduced from the results. The results may provide a scientific foundation for deeply elucidating the wine-processing mechanism of LLF.