Ultrahigh-performance Liquid Chromatography Orbitrap Research Articles

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.

Biomarkers related to cognitive dysfunction in APP/PS1 mice based on non-targeted metabonomics and intervention mechanism of Huanglian Jiedu Decoction

Through the non-targeted metabonomics study on endogenous substances in APP/PS1 transgenic mice, this paper aimed to discover biomarkers related to APP/PS1 mice with cognitive dysfunction, and find targets of Huanglian Jiedu Decoction(HLJDD) in the treatment of Alzheimer's disease(AD) and its mechanism. The brain tissue and serum metabolic mass spectrometry of mice were analyzed by ultra-high performance liquid chromatography-Orbitrap mass spectrometry(UPLC-Orbitrap MS). Through partial least squares-discriminant analysis(PLS-DA) and orthogonal partial least squares-discriminant analysis(OPLS-DA), the metabolic data of the normal group, the model group, the high-dose and low-dose HLJDD groups, and the berberine group were compared and analyzed to screen out potential biomarkers, and the relevant metabolic pathways were constructed with the help of the Kyoto Encyclopedia of Genes and Genomes(KEGG) database. Forty-five potential endogenous metabolites were identified, including 13 in brain and 35 in serum, among which leukotriene B4, tyrosine, and adenosine were expected to be differential metabolites related to cognitive function. HLJDD recalled 22 differential metabolites, and the pathways mainly involved in aminoacyl-tRNA biosynthesis, valine, leucine and isoleucine biosynthesis, pantothenic acid and coenzyme A biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, and arachidonic acid metabolism. These pathways suggested that the main mechanism of HLJDD in the intervention of AD was to inhibit central and peripheral inflammation, and regulate energy metabolism, fatty acid metabolism, and amino acid metabolism. HLJDD has a certain effect on the improvement of cognitive dysfunction, and regulates relative pathways by recalling endogenous differential metabolites, which helps to further discover the biomarkers of AD and clarify the intervention mechanism of HLJDD in the treatment of AD.

Structure identification and toxicity evaluation of one newly-discovered dechlorinated photoproducts of chlorpyrifos.

Chlorpyrifos (CPF) is an extensively used organophosphorus pesticide. Recently, it has attracted increasing attention due to environmental health problems caused by it. Although numerous studies have discovered the dechlorinated photoproduct of CPF, its structure and toxicity remain largely unknown. In this study, we systematically investigated the structure and toxicity of dechlorinated photoproduct of CPF. The CPF degradation experiment was performed, and its products were identified by ultra high performance liquid chromatography-orbitrap fusion tribid mass spectrometer (UHPLC-Orbitrap Fusion TMS). Additionally, bond dissociation energy (BDE) calculations and photoproduct chemical synthesis were employed to determine the structure of dechlorinated photoproduct of CPF. The toxicity of CPF photoproduct was evaluated through the Ecological Structure Activity Relationships (ECOSAR) Class Program, the Toxicity Estimation Software Tool (T.E.S.T.) software, and acute toxicity testing. The results indicated that the dechlorinated photoproduct of CPF was identified as O,O-Diethyl-O-(3,5-dichloro-2-pyridyl) phosphorothioate (Dechloro-CPF), which was produced in large quantity within the first 30min of photodegradation experiment. The acute and chronic toxicity values of Dechloro-CPF were obviously higher than those for the other two photoproducts. The median lethal dose (LD50) of Dechloro-CPF was 31.6mg/kg for female mice and 58.4mg/kg for male mice. This study reveals the photodegradation mechanism of CPF and confirms that Dechloro-CPF was dechlorinated photoproduct of CPF with potential acute toxicity to aquatic species and mammalian (including human). Our findings will contribute to a more comprehensive risk evaluation of CPF in food and the environment.

Systematic characterization of the components and molecular mechanisms of Jinshui Huanxian granules using UPLC-Orbitrap Fusion MS integrated with network pharmacology

Jinshui Huanxian granules (JSHX) is a clinical Chinese medicine formula used for treating pulmonary fibrosis (PF). However, the effective components and molecular mechanisms of JSHX are still unclear. In this study, a combination approach using ultra-high performance liquid chromatography-Orbitrap Fusion mass spectrometry (UPLC-Orbitrap Fusion MS) integrated with network pharmacology was followed to identify the components of JSHX and the underlying molecular mechanisms against PF. UPLC-Orbitrap Fusion MS was used to identify the components present in JSHX. On the basis of the identified components, we performed target prediction using the SwissTargetPrediction database, protein–protein interaction (PPI) analysis using STRING database, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis using Metascape and constructed a component-target-pathway network using Cytoscape 3.7.2. Molecular docking technology was used to verify the affinity between the core components and targets. Finally, the pharmacological activities of three potentially bioactive components were validated in transforming growth factor β1 (TGF-β1)-induced A549 cell fibrosis model. As a result, we identified 266 components, including 56 flavonoids, 52 saponins, 31 alkaloids, 10 coumarins, 12 terpenoids and 105 other components. Of these, 90 validated components were predicted to act on 172 PF-related targets and they exhibited therapeutic effects against PF via regulation of cell migration, regulation of the mitogen-activated protein kinase (MAPK) cascade, reduction of oxidative stress, and anti-inflammatory activity. Molecular docking showed that the core components could spontaneously bind to receptor proteins with a strong binding force. In vitro, compared to model group, hesperetin, ruscogenin and liquiritin significantly inhibited the increase of α-smooth muscle actin (α-SMA) and fibronectin (FN) and the decrease of e-cadherin (E-cad) in TGF-β1-induced A549 cells. This study is the first to show, using UPLC-Orbitrap Fusion MS combined with network pharmacology and experimental validation, that JSHX might exert therapeutic actions against PF by suppressing the expression of key factors in PF. The findings provide a deeper understanding of the chemical profiling and pharmacological activities of JSHX and a reference for further scientific research and clinical use of JSHX in PF treatment.

Alkaloid Profiling, Anti-Enzymatic and Antiproliferative Activity of the Endemic Chilean Amaryllidaceae Phycella cyrtanthoides

This research aims to identify the alkaloid profile and to evaluate the enzyme inhibitory potential and antiproliferative effects of the Amaryllidaceae plant Phycella cyrtanthoides. The alkaloid extracts from bulbs and leaves were analyzed using ultrahigh performance liquid chromatography orbitrap mass spectrometry (UHPLC-Orbitrap-MS) analysis. A total of 70 alkaloids were detected in the P. cyrtanthoides’ extracts. The enzyme inhibition potential against cholinesterases (AChE: acetylcholinesterase, and BChE butyrylcholinesterase) and tyrosinase were studied. Bulbs displayed the best IC50 values against AChE (4.29 ± 0.03 µg/mL) and BChE (18.32 ± 0.03 µg/mL). These results were consistent with docking experiments with selected major compounds in the active sites of enzymes, while no activity was observed against tyrosinase enzyme. Antiproliferative effects were investigated against human cervical (HeLa), lung (A549, SW1573), colon (WiDr), and breast (HBL-100, T-47D) tumor cell lines. Bulbs and leaves were active in all cell lines (GI50 < 2.5 µg/mL). These findings suggest that the endemic Chilean plant P. cyrtanthoides contains diverse types of bioactive alkaloids with antiproliferative activities and inhibitory effects with potential therapeutic applications for neurodegenerative diseases

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.

Isolation and quantification of diarylheptanoids from European hornbeam (Carpinus betulus L.) and HPLC-ESI-MS/MS characterization of its antioxidative phenolics

Detailed polyphenol profiling of European hornbeam (Carpinus betulus L.) bark, leaf, male and female catkin extracts was performed by high-performance liquid chromatography–diode array detection coupled to tandem mass spectrometry (HPLC-DAD-MS/MS). A total of 194 compounds were characterized and tentatively identified. Gallo- and ellagitannins dominated in the methanol extracts, while flavonol glycosides and methoxylated flavones prevailed in the ethyl acetate samples. In the quest for diarylheptanoids, twelve compounds were isolated by the combination of subsequent reversed-phase flash chromatographic and high-performance liquid chromatographic methods. The structural elucidation of the isolated components was performed by ultrahigh-performance liquid chromatography-Orbitrap mass spectrometry (UHPLC‐Orbitrap‐MS) as well as 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. Six known cyclic diarylheptanoids, together with a new compound were described in Carpinus betulus for the first time. The occurrence of a linear diarylheptanoid and a lignan has also been unprecedented in the genus Carpinus. Moreover, three known flavonol glycosides were isolated. Based on the identification of characteristic fragment ions, a new mass spectrometric fragmentation pathway for meta,meta-cyclophane-type diarylheptanoids was proposed. Quantities of the four major cyclic diarylheptanoids in European hornbeam were determined by a validated UHPLC-DAD method for the first time. The antioxidant properties of the extracts and the isolated compounds were assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Contribution of the individual constituents to the total radical scavenging activity of the samples was evaluated by an off-line DPPH-HPLC-DAD method. This allowed the identification of gallo- and ellagitannin derivatives as the constituents being primarily responsible for the antioxidant capacity of the extracts.

Analysis and comparison of key proteins in Maiwa yak and bovine milk using high-performance liquid chromatography mass spectrometry

Yak milk is an essential and predominant food resource for Tibetan people for subsistence purposes and to combat altitude-induced challenges. Due to its unique qualities, yak milk has recently been gaining broader attention from consumers across China as well in other parts of the world. One of the key characteristics of yak milk is the protein content, which is about 40 to 60% higher than that of native bovine milk. In this work, a sensitive and reproducible high-throughput analytical method was developed employing both ultra high-performance liquid chromatography Orbitrap (Thermo Fisher Scientific) high-resolution accurate mass spectroscopy (UHPLC-HRAM-MS) and UHPLC coupled with triple quadrupole tandem MS (UHPLC-QqQ-MS) to simultaneously analyze 8 milk proteins. A total of 15 Maiwa yak milk samples and 15 bovine milk samples were qualitatively and quantitatively analyzed using targeted proteomics and compared for α-lactalbumin, β-lactoglobulin, αS1-casein, αS2-casein, β-casein, κ-casein, lactoferrin, and osteopontin. Peptides of β-lactoglobulin were used to specifically distinguish yak and bovine milk. The results showed that this novel detection method could quantitatively detect these major and minor milk proteins with >0.99 linear correlation coefficient and a recovery rate between 90 and 120%, with relative standard deviations typically less than 10%. The data revealed that yak milk not only had higher overall milk protein content than bovine milk but higher lactoferrin and osteopontin contents as well. The lactoferrin content of yak milk was about 30% higher than that of bovine milk, and the osteopontin content of yak milk was nearly twice that of bovine milk. The application of this method demonstrates that UHPLC-HRAM-MS and UHPLC-QqQ-MS are suitable for high-throughput qualitative and quantitative analysis of major and minor proteins of yak and bovine milk.

Orbitrap-MS-based untargeted metabolomics study on the therapeutic effect of colchicine on myocardial infarction.

Myocardial infarction (MI) is one of the most common causes of death worldwide. A metabolomic approach based on an ultra-high performance liquid chromatography-Orbitrap analytical method was established to analyze the metabolites and to investigate the therapeutic mechanism of colchicine. Forty-six biomarkers were significantly changed between the sham group and the MI group. Thirty-five metabolites were increased and 11 were decreased in MI rats, and colchicine reversed all of them. Pathway analysis showed that the TCA cycle, alanine, aspartate and glutamate metabolism, glycerophospholipid metabolism, aminoacyl-tRNA biosynthesis, glyoxylate and dicarboxylate metabolism and arginine biosynthesis were altered in the MI group. Ingenuity pathway function and network analysis showed that colchicine improved MI through regulation of cardiac β-adrenergic signaling and cardiac hypertrophy signaling. The present study provided a useful approach for exploring the mechanism of MI and evaluating the efficacy of colchicine.

Chemical Profiling, Antioxidant, Anticholinesterase, and Antiprotozoal Potentials of Artemisia copa Phil. (Asteraceae)

Artemisia copa Phil. (Asteraceae) (known as copa-copa) is a native species of Chile used as an infusion in traditional medicine by Atacameños people in the Altiplano, highlands of northern Chile. In this research, we have investigated for the first time the cholinesterase inhibition potential against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and the chemical profiling of the infusions prepared from the aerial parts of A. copa by high resolution spectrometry. In addition, total phenolic, total flavonoid content, antioxidant (DPPH, FRAP, and ORAC) and antiprozoal activity were tested. Artemisia copa showed good inhibitory activity against AChE and BChE (3.92 ± 0.08 µg/ml and 44.13 ± 0.10 µg/ml). The infusion displayed a total phenolics content of 155.6 ± 2.9 mg of gallic acid equivalents/g and total flavonoid content of 5.5 ± 0.2 mg quercetin equivalents/g. Additionally, trypanocidal activity against Trypanosoma cruzi was found (LD50 of 131.8 µg/ml). Forty-seven metabolites were detected in the infusion of A. copa including several phenolic acids and flavonoids which were rapidly identified using ultrahigh performance liquid chromatography orbitrap mass spectrometry analysis (UHPLC-Orbitrap-MS) for chemical profiling. The major compounds identified in the infusions were studied by molecular docking against AChE and BChE. The UHPLC-MS fingerprints generated can be also used for the authentication of these endemic species. These findings reveal that A. copa infusions can be used as beverages with protective effects.

Rapid Characterizaiton of Chemical Constituents of the Tubers of Gymnadenia conopsea by UPLC-Orbitrap-MS/MS Analysis.

Gymnadenia conopsea R. Br. is a traditional Tibetan medicinal plant that grows at altitudes above 3000 m, which is used to treat neurasthenia, asthma, coughs, and chronic hepatitis. However, a comprehensive configuration of the chemical profile of this plant has not been reported because of the complexity of its chemical constituents. In this study, a rapid and precise method based on ultra-high performance liquid chromatography (UPLC) combined with an Orbitrap mass spectrometer (UPLC–Orbitrap–MS/MS) was established in both positive- and negative-ion modes to rapidly identify various chemical components in the tubers of G. conopsea for the first time. Finally, a total of 91 compounds, including 17 succinic acid ester glycosides, 9 stilbenes, 6 phenanthrenes, 19 alkaloids, 11 terpenoids and steroids, 20 phenolic acid derivatives, and 9 others, were identified in the tubers of G. conopsea based on the accurate mass within 3 ppm error. Furthermore, many alkaloids, phenolic acid derivates, and terpenes were reported from G. conopsea for the first time. This rapid method provides an important scientific basis for further study on the cultivation, clinical application, and functional food of G. conopsea.

Untargeted Lipidomics Reveals Specific Lipid Abnormalities in Nonfunctioning Human Pituitary Adenomas.

The pituitary gland is a small but important organ located in the base of the brain. Although mostly noncancerous, pituitary adenomas (PAs) can cause serious health problems such as headaches, visual field defects, double vision, and hypopituitarism by invasion of regional structures. Nonfunctioning PAs (NFPAs) approximately account for one-third of PAs manifested by no circulating hormone hypersecretion. Lipid reprogramming has been recognized as a hallmark of tumor cells and proven to play a crucial role in tumorigenesis. However, the lipid molecular pathogenesis of NFPAs has remained obscure to date. To uncover lipid alterations that may contribute to the development of NFPAs and define their molecular characteristics, we investigated tissue lipids of patients with NFPAs including eight null cell adenomas (NCAs) and eight oncocytomas (OCMs) and of five normal pituitary glands as the control (Ctrl) using nontargeted lipidomics based on ultrahigh-performance liquid chromatography-Orbitrap Q-Exactive HF mass spectrometry. The lipidomic results were further validated in another set of subjects consisting of 8 NCAs, 10 OCMs, and 6 Ctrls to define crucial lipids discriminating NFPAs from the normal pituitary tumors. Lipidomic analyses revealed that OCM showed more pronounced changes in lipid compositions than NCA and Ctrl. As expected, mitochondria abundant cardiolipins were remarkably increased in OCM, which was accordant with the biochemical evidence of mitochondria hyperplasia in OCM. Significantly increased levels of phospholipids (PLs), especially arachidonic acid (AA)-enriched PLs, were unique characteristics of lipid profiling in OCM vs Ctrl. Our results indicate that AA-PLs may have diagnostic potential for OCM.

In vivo toxicity assessment of Clinopodium vulgare L. water extract characterized by UHPLC-HRMS

Clinopodium vulgare L. (Lamiaceae) was used in the traditional Bulgarian medicine for treatment of wounds, diabetes and gastric ulcers. In this study we aimed at safety assessment of C. vulgare lyophilized water extract (CVE) characterized by ultra high-performance liquid chromatography–Orbitrap high resolution mass spectrometry (UHPLC-HRMS). The acute and sub-acute toxicity of CVE was determined in two rodent species (mice and rats), and two routes of administration – intraperitoneal (i.p.) and oral (p.o.). LD50 (i.p.), were found to be 675 mg/kg (mice) and 500 mg/kg (rats). An acute i. p. administration resulted in central nervous system toxic effects. LD50 (p.o.) was higher than 2000 mg/kg for both species. In sub-acute oral administration, CVE did not exert any toxic effect on hematology, blood and urine biochemistry, and histomorphology in pancreas, liver, spleen and kidney. In addition, based on accurate masses, MS/MS and comparison with standards, a variety of flavonoids, caffeic acid oligomers and saponins were tentatively elucidated in CVE. Rosmarinic acid was the major compound. In conclusion, CVE did not cause hematological, biochemical and histopathological changes after oral administration and it is safe for internal use. The obtained UHPLC-HRMS profile revealed CVE as a new rich source of water soluble caffeic acid oligomers.

Monitoring of organophosphate and pyrethroid metabolites in human urine samples by an automated method (TurboFlow™) coupled to ultra-high performance liquid chromatography-Orbitrap mass spectrometry

There is a growing concern to pesticide exposure in humans, being the organophosphate (OP), carbamate and pyrethroid the most commonly used insecticides. Therefore, a fast, simple and automated screening method based on ultra-high performance liquid chromatography coupled to Orbitrap high resolution mass spectrometry (UHPLC-Orbitrap-MS) has been developed to determine six OPs metabolites (3,5,6-trichloro-2-pyridinol “TCPy”, 2-isopropyl-6-methyl-4-pyrimidinol “IMPY”, 4-nitrophenol “PNP”, 4-nitrophenol-d4 “PNP-d4″, 3-chloro-7-hydroxy-4-methylcoumarin “CMHC” and 2-diethylamino-6-methylpyrimidin-4ol “DEAMPY”) and three pyrethroid metabolites (3-phenoxybenzoic acid “3-PBA”, 4-fluoro-3-phenoxybenzoic acid “4-F-3-PBA” and 3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropanecarboxylic acid “cis/trans-DCCA”) in human urine samples. Off-line solid phase extraction (SPE), on-line SPE and turbulent flow chromatography (TurboFlow™) extraction methodologies were compared, obtaining better results when TurboFlow™ was applied, achieving a total analysis time of 13.83 min. Several validation parameters were tested, obtaining suitable results for all studied compounds. Recoveries ranged from 70 to 116%, meanwhile repeatability and reproducibility were lower than or equal to 7% and 13%, respectively. The limits of quantification (LOQs) were set in the range from 1 μg/L to 5 μg/L (except for DCCA at 10 μg/L). Finally, thirty seven urine samples from women and men living near the agricultural areas of Almeria (Spain) were analyzed to know and control the contamination on the human health. PNP, DEAMPY and IMPY were detected in six urine samples at trace levels except IMPY, which was detected at 3.44 μg/L in one of the samples. Additionally, a post-targeted and untargeted analysis were carried out in the samples, identifying eleven insecticides such as bensulide or cinerin II, one insecticide metabolite, fipronil sulfone, one drug metabolite, carboxyibuprofen and two nicotine metabolites, cotinine and 2-(1-pyrrolidinyl)isonicotinic acid, in several samples.

Evaluation of bisphenol A exposure induced oxidative RNA damage by liquid chromatography-mass spectrometry

Highlighted evidence suggests the possible implication of bisphenol A (BPA) exposure on a variety of biological functions, such as DNA damage. Similar to DNA, exposed to BPA may also have potential risks to RNA damage due to its induction of reactive oxygen species. However, there are no related research reports about such health risks of BPA. Therefore, this work tried to investigate the BPA exposure induced oxidative RNA damage by detecting urinary nucleosides, the end-products of RNA metabolism. An ultra-high performance liquid chromatography-Orbitrap mass spectrometry method was applied to selectively and sensitively determine urinary nucleosides. As a result, 66 nucleosides were identified and the effects of BPA exposure on these nucleosides in rat urine samples were evaluated. The nucleosides showed different changing tendency along with different exposure dose of BPA. The strongest effect was observed in high does-exposure rats, indicating dose-response relationship between BPA-treatment and urinary nucleosides. Significant change of some nucleosides, including 8-oxoguanosine, was observed in the high-dose exposure group, suggesting obvious RNA damage to rats. To the best of our knowledge, it is the first study about the RNA damage induced by BPA exposure. The results provided a new perspective on the toxic effects of BPA exposure.

Psychiatrics and selected metabolites in hospital and urban wastewaters: Occurrence, removal, mass loading, seasonal influence and risk assessment

The occurrence, removal, mass loading, seasonal influence and environmental risk assessment of nine psychiatric pharmaceuticals and four of their selected metabolites, were studied in one hospital and one urban wastewater treatment plant (WWTP) in Ioannina city, in northwestern Greece, providing information about the efficiency of the plants and their contribution into the final receiver's flow. Samples were collected from the influents and the effluents of the plants in different sampling campaigns, from July to December 2016. Analytical methodology was based on ultra-high performance liquid chromatography-Orbitrap high-resolution mass spectrometry, after solid-phase extraction through Oasis HLB cartridges. Concentrations in both WWTPs ranged between <LOQ and 1126.3 ng/L in the influents and between <LOQ and 1127.4 ng/L, in the effluents. Results indicated that venlafaxine and its metabolite O-desmethyl venlafaxine were the most frequently detected compounds in the influents and the effluents of both WWTPs. Metabolite to parent compound ratio ranged in the influents between 0.01 and 87.2 while in the effluents between 0.01 and 47.7. Based on mass loads in the influents, venlafaxine is consumed in high amounts (up to 67.1 mg/day/1000 inhab.), and consequently its metabolite O-desmethyl venlafaxine (up to 139.1 mg/day/1000 inhab.). Similarly to the influents, environmental emissions, were also higher for venlafaxine and O-desmethyl venlafaxine (10.1 and 13.3 mg/d/1000 inhab., respectively). Removal efficiencies in the hospital WWTP ranged from −100% to 98.9%, while in the city WWTP from −49.9% to 99.8%. Furthermore, an important outcome was the evaluation of the potential ecotoxicological risk, by means of risk quotients (RQs), where none of the target psychiatrics or their metabolites showed RQ above 1.

Determination of steviol glycosides in commercial extracts of Stevia rebaudiana and sweeteners by ultra-high performance liquid chromatography Orbitrap mass spectrometry

Stevia rebaudiana extracts are used as sweeteners in several countries worldwide. Several extracts of diverse composition are available on the market, and their taste depends on the contents of the various steviol glycosides. This study presents an accurate method for the qualitative and quantitative determination of steviol glycosides in 40 Stevia extracts, 7 sweeteners and 3 Stevia-sweetened beverages by a UHPLC coupled to an Orbitrap mass spectrometer. The sub-2 μm amide column provided the separation of all the target analytes in a run time of 30 min with high resolution. The effect of different eluent compositions on the ionisation efficiency of the steviol glycosides was studied. The optimal ionisation conditions were achieved in negative mode using 0.05% formic acid. Under this condition, adducts were not found, [M-H]− were the main ions and the spontaneous loss of a glucose residue at C19 was reduced. The %RSD for intra- and inter-day precision for all eleven analytes varied from 2.1 to 4.2% and 3.0–5.1%, respectively. The recoveries from spiked Stevia extract samples were greater than 95% for all analytes. Rebaudioside A was the most abundant, ranging from 23 to 102%. Nine Stevia extracts and one drink were not compliant with the European Regulation. Isosteviol was under the LOD in all samples and steviol was found in four samples in quantities in the range 0.01–0.03%.

Determination of steroid hormones and their metabolite in several types of meat samples by ultra high performance liquid chromatography—Orbitrap high resolution mass spectrometry

A new analytical method based on ultra-high performance liquid chromatography (UHPLC) coupled to Orbitrap high resolution mass spectrometry (Orbitrap-HRMS) has been developed for the determination of steroid hormones (hydrocortisone, cortisone, progesterone, prednisone, prednisolone, testosterone, melengesterol acetate, hydrocortisone-21-acetate, cortisone-21-acetate, testosterone propionate, 17α-methyltestosterone, 6α-methylprednisolone and medroxyprogesterone) and their metabolite (17α-hydroxyprogesterone) in three meat samples (chicken, pork and beef). Two different extraction approaches were tested (QuEChERS “quick, easy, cheap, effective, rugged and safe” and “dilute and shoot”), observing that the QuEChERS method provided the best results in terms of recovery. A clean-up step was applied comparing several sorbents, obtaining the best results when florisil and aluminum oxide were used. The optimized method was validated, obtaining suitable results for all validation parameters in the three meat matrices evaluated. Recovery values ranged from 70% to 103% (except for prednisone in beef samples), meanwhile repeatability and reproducibility were obtained at values lower than 18% and 21%, respectively. The limit of quantification (LOQ) was established for most of the compounds at 1.0 μg/kg, except for testosterone in chicken and hydrocortisone-21-acetate and cortisone-21-acetate in pork at 2.0 μg/kg. Decision limit (CCα) and detection capability (CCβ) values ranged from 1.0–2.7 μg/kg and 1.9–5.5 μg/kg, respectively, in the three matrices. Finally, thirty one meat samples were analyzed and two hormones, progesterone and hydrocortisone, were detected in a beef and pork sample at 1.7 and 2.8 μg/kg respectively.

Development of a simple multi-residue determination method of 80 veterinary drugs in Oplegnathus punctatus by liquid chromatography coupled to quadrupole Orbitrap mass spectrometry.

A simple, rapid and sensitive multi-residue analytical method was developed and validated for 80 veterinary drugs in Oplegnathus punctatus using ultrahigh performance liquid chromatography-Orbitrap high resolution mass spectrometry (LC-HRMS). The analytes belong to 12 different families include benzimidazoles, β-lactams, lincosamides, macrolides, nitromidazoles, quinolones, sulfonamides and trimethoprim, tetracyclines, triphenylmethane dyes, amphenicols, nonsteroidal estrogens and steroid hormones. The sample preparation was optimized base on QuEChERS (quick, easy, cheap, effective, rugged and safe) procedure. A very simple and sufficient preparation procedure without salting-out and complex clean-up process was studied. It had been proved that water in the extract was helpful for extracting hydrophilic compounds and precipitating the lipids during the subsequent cleaning process. In addition, an appropriate percent of methanol was necessary to some analytes. Finally, a mixture of acetonitrile, methanol and water (3:1:1, v/v/v) which include 1% acetic acid and 10mM ethylenediaminetetraacetic acid disodium salt 2-hydrate was selected as the extraction solvent, and the clean-up step consisted of a low temperature procedure and two times of high-speed centrifugation to deproteinize and remove lipids. The detection and quantification of all compounds were performed by ultrahigh performance liquid chromatography coupled with electrospray ionization quadrupole Orbitrap high resolution mass spectrometry in positive and negative ion mode. This methodology was validated according to the Commission Decision 2002/657/EC and SANTE/11945/2015. The recoveries ranged from 60.74%-109.85% with relative standard deviations (RSDs)<20%. The limits of quantification (LOQs) were 0.25-25ug/kg, for the analytes which the MRL or MRPL had been established in fish tissue, the LOQs were all lower than their own legal tolerances. The values of decision limit (CCα) and detection capability (CCβ) were in the range of 1.91-1001.13ug/kg and 3.52-1002.26ug/kg, respectively. This validated method has been successfully applied on the determination of veterinary drugs in real commercial oplegnathus punctatus samples.

Direct sample analysis-mass spectrometry vs separation mass spectrometry techniques for the analysis of writing inks

Direct sample analysis (DSA) coupled with high resolution, high mass accuracy time of flight mass spectrometry (TOF-MS) is an emerging technique for the in situ analysis of various substances. DSA is similar to desorption electrospray ionization (DESI) and direct analysis in real time (DART), however, it uses an atmospheric pressure chemical ionization source for ionization of organic compounds. In this study, DSA was applied to the identification of 80 black and blue writing inks from both ballpoint and non-ballpoint pens. Approximately 3mm sections of each writing was placed on the DSA sample holder and analyzed in an automated fashion. The holder can analyze 13 samples in a serial manner. Utilizing a high mass accuracy TOF-MS and using internal calibration, mass accuracy of <6ppm was achieved. Moreover, the results obtained from DSA analysis were compared with the extraction of the ink from the paper and its analysis by gas chromatography–mass spectrometry (GC–MS) and nano ultra-high performance liquid chromatography–Orbitrap mass spectrometry (nLC–MS). Analysis by DSA and LC-MS resulted in the identification of colorants as well as vehicles and additives while analysis by GC–MS mainly resulted in the identification of the non-colorant ingredients. Of the three techniques utilized, DSA provided the greatest number of ink compound identifications and in more samples. However, no single method detected all the components of the ink formulations. For profiling purposes, it is therefore necessary to utilize more than one method, such as the combination of DSA, LC-MS, and GC–MS presented in this study.