Search

International audience; The oxidation of a stoichiometric diethyl ether-oxygen-nitrogen mixture containing 5000 ppm of fuel was studied in a jet-stirred reactor at 10 atm and a residence times of 1 s. Experimental temperatures varied stepwise for 440 to 740 K and products were quantified by gas chromatography with TCD and FID, gas chromatography-mass spectrometry, and FTIR. Other experiments in the temperature range 480 to 570 K were performed for characterizing elusive cool flame products. To this end, gas samples were trapped in acetonitrile for flow injection analyses and liquid chromatography-mass spectrometry (Orbitrap Q-Exactive®). For ionization, we used positive and negative atmospheric pressure chemical ionization (APCI). Among fuel-specific products, hydroperoxides and diols (C4H10O3), carbonyl hydroperoxides (C4H8O4), acetic acid, di-keto ethers (C4H6O3), cyclic ethers (C4H8O2) and highly oxygenated molecules, i.e., keto-dihydroperoxides (C4H8O6), keto-trihydroperoxides (C4H8O8), di-keto-hydroperoxides (C4H6O5), and diketo-dihydroperoxides (C4H6O7), were detected. To confirm the presence of –OH or –OOH groups in oxidation products, H/D exchange with D2O was used. DNPH derivatization was used to identify carbonyls present in samples, especially those with a molecular weight below 50 amu which cannot be detected directly by the mass spectrometer. Chemical kinetic modeling using a mechanism taken from the literature was performed. Although reasonable agreement between the data and the simulations was observed for several species, some discrepancies between experimental and computed mole fractions were observed.

Background: The reports about valuable oligosaccharides in ginseng are quite limited. There is an urgent need to develop a practical procedure to detect and analyze ginseng oligosaccharides. Methods: The oligosaccharide extracts from ginseng were permethylated by solid-phase methylation method and then were analyzed by ultra-high-performance liquid chromatography-Q-Orbitrap/MS. The sequence, linkage, and configuration information of oligosaccharides were determined by using accurate m/z value and tandem mass information. Several standard references were used to further confirm the identification. The oligosaccharide composition in white ginseng and red ginseng was compared using a multivariate statistical analysis method. Results: The nonreducing oligosaccharide erlose among 12 oligosaccharides identified was reported for the first time in ginseng. In the comparison of the oligosaccharide extracts from white ginseng and red ginseng, a clear separation was observed in the partial least squares-discriminate analysis score plot, indicating the sugar differences in these two kinds of ginseng samples. The glycans with variable importance in the projection value large than 1.0 were considered to contribute most to the classification. The contents of oligosaccharides in red ginseng were lower than those in white ginseng, and the contents of maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, maltooctaose, maltononaose, sucrose, and erlose decreased significantly (p

Targeted metabolomics has significant advantages for quantification but suffers from reduced metabolite coverage. In this study, we developed a large-scale targeted metabolomics method and expanded its applicability to various human samples. This approach initially involved unbiased identification of metabolites in human cells, tissues and body fluids using ultra high-performance liquid chromatography (UHPLC) coupled to high-resolution Orbitrap mass spectrometry (MS). Targeted metabolomics method was established with utility of UHPLC-triple quadrupole MS, which enables targeted profiling of over 400 biologically important metabolites (e.g., amino acids, sugars, nucleotides, dipeptides, coenzymes, and fatty acids), covering 92 metabolic pathways (e.g., Krebs cycle, glycolysis, amino acids metabolism, ammonia recycling, and one-carbon metabolism). The present method displayed better sensitivity, repeatability and linearity than the Orbitrap MS-based untargeted metabolomics approach and demonstrated excellent performance in lung cancer biomarker discovery, in which 107 differential metabolites were able to discriminate between carcinoma and adjacent normal tissues, implicating the Warburg effect, alteration of redox state, and nucleotide metabolism of lung cancer. This new method is flexible and expandable and offers many advantages for metabolomics analysis, such as wide metabolite coverage, good repeatability and linearity and excellent capability in biomarker discovery, making it useful for both basic and clinical metabolic research.

The identification of T cell epitopes derived from tumour specific antigens remains a significant challenge for the development of peptide-based vaccines and immunotherapies. The use of mass spectrometry-based approaches (immunopeptidomics) can provide powerful new avenues for the identification of such epitopes. In this study we report the use of complementary peptide antigen enrichment methods and a comprehensive mass spectrometric acquisition strategy to provide in-depth immunopeptidome data for the THP-1 cell line, a cell line used widely as a model of human leukaemia. To accomplish this, we combined robust experimental workflows that incorporated ultrafiltration or off-line reversed phase chromatography to enrich peptide ligand as well as a multifaceted data acquisition strategy using an Orbitrap Fusion LC-MS instrument. Using the combined datasets from the two ligand enrichment methods we gained significant depth in immunopeptidome coverage by identifying a total of 41,816 HLA class I peptides from THP-1 cells, including a significant number of peptides derived from different oncogenes or over expressed proteins associated with cancer. The physicochemical properties of the HLA-bound peptides dictated their recovery using the two ligand enrichment approaches and their distribution across the different precursor charge states considered in the data acquisition strategy. The data highlight the complementarity of the two enrichment procedures, and in cases where sample is not limiting, suggest that the combination of both approaches will yield the most comprehensive immunopeptidome information.

Bombyx batryticatus is the dried dead larva of silkworms after infection by a fatal fungi Beauveria bassiana. It's a challenging task to monitor intrinsic biological macromolecules in this natural medicine. In this study, a novel strategy based on comparative proteomic analysis was developed to disclose inherent differences between processed and highly processed Bombyx batryticatus. First, protein and amino acid contents were determined, and the changes in proteins after highly processing the medicine were profiled through electrophoresis-based technologies. Then, the peptides that originated from the differentiated proteins were eluted under reversed-phase NanoLC and sequenced by orbitrap MSD. It was found that both contents had been significantly decreased after processed Bombyx batryticatus was stir-baked with wheat bran. Additionally, protein bands and spots visualized in SDS-PAGE and 2-DE profiles of the processed product were much brighter than those of the highly processed product, allowing them to be distinguished by electrophoresis profiling readily. Moreover, thirty-two signature proteins were identified as potential biomarkers by NanoLC-orbitrap MSD after in-gel tryptic digestion of specific bands and spots. This work provides a solid scientific basis for quality assessment and control of commercial products of this natural medicine, and the developed novel strategy could ensure its safety and efficacy.

Acanthopanax senticosus is an important medicinal and edible homologous plant that is widely used in medicines, health products, and functional beverages. Phytochemicals present in plants are partly responsible for various health benefits. Traditional extraction methods use a large number of high-risk organic solvents (acetone, chloroform, etc.) that are potential threats to the environment, human health, and food safety. However, a persistent problem remains in this field with regards to extraction using a simple "green" method. Therefore, a deep eutectic solvent (DES) was used instead of traditional high-risk organic solvents to extract the phytochemicals from Acanthopanax senticosus root. In this study, DES was synthesized from choline chloride and lactic acid, which was used as a substitute for a strong organic solvent to extract saponins, phenylpropionic acid, and terpenoids from Acanthopanax senticosus root. The phytochemicals extracted from Acanthopanax senticosus were analyzed by ultra-high-performance liquid chromatography with quadrupole orbitrap mass spectrometry in positive and negative ionization modes. A total of 91 types of phytochemicals were identified from DES extracts and 17 chemical constituents were newly identified in the root of Acanthopanax senticosus via primary and secondary high-resolution mass spectrometry (MS1/MS2). Furthermore, DES was demonstrated as a promising functional component of the extraction solvent, and its non-toxic properties endow broad application prospects in the food and health products industries.

Lonicerae Japonicae Flos (LJF), a kind of traditional Chinese medicines (TCMs), has functions of detoxifying and evacuating heat. In the study, a method based on ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap MS) was developed for the chemical constituent analysis of organic acids, flavonoids, iridoids and new-generated compounds in sulfur-fumigated LJF (SF-LJF). Based on the accurate mass measurement (< ± 5 ppm), chromatographic behavior and diagnostic product ions (DPIs), 113 constituents were unambiguously or tentatively characterized from SF-LJF extract, including 46 chlorogenic acids, 19 flavonoids, 29 iridoid glycosides and 19 newly-generated compounds (including 17 sulfur-containing derivatives). In addition, 5-CQA (5-caffeoylquinic acid, chlorogenic acid) was chosen to be sulfur-fumigated for the result validation. It was found that the most significant change of LJF after sulfur fumigation was the occurrence of sulfate or sulfite esterification reactions, which resulted in the emergence of many new sulfur-containing components. Our results demonstrated that the established method was a useful and efficient analytical tool to comprehensively characterize the material basis of SF-LJF, and also an excellent guidance of quality control about LJF.

DIA profiles of complex biological matrices such as tissues can contain quantitative interferences, and the interferences at the MS1 and the MS2 signals are often independent. We developed a statistical procedure incorporating both MS1 and MS2 quantitative information of DIA. We benchmarked the performance of the MS1-MS2-combined method to the individual use of MS1 or MS2 in DIA. In the majority of the comparisons, the combined method outperformed the individual use of MS1 or MS2., Graphical Abstract Highlights Modern DIA methods contain high quality MS1 and MS2. We developed a statistical procedure incorporating MS1 and MS2. Benchmarking, the combined method outperformed the individual use of MS1 or MS2., In bottom-up, label-free discovery proteomics, biological samples are acquired in a data-dependent (DDA) or data-independent (DIA) manner, with peptide signals recorded in an intact (MS1) and fragmented (MS2) form. While DDA has only the MS1 space for quantification, DIA contains both MS1 and MS2 at high quantitative quality. DIA profiles of complex biological matrices such as tissues or cells can contain quantitative interferences, and the interferences at the MS1 and the MS2 signals are often independent. When comparing biological conditions, the interferences can compromise the detection of differential peptide or protein abundance and lead to false positive or false negative conclusions. We hypothesized that the combined use of MS1 and MS2 quantitative signals could improve our ability to detect differentially abundant proteins. Therefore, we developed a statistical procedure incorporating both MS1 and MS2 quantitative information of DIA. We benchmarked the performance of the MS1-MS2-combined method to the individual use of MS1 or MS2 in DIA using four previously published controlled mixtures, as well as in two previously unpublished controlled mixtures. In the majority of the comparisons, the combined method outperformed the individual use of MS1 or MS2. This was particularly true for comparisons with low fold changes, few replicates, and situations where MS1 and MS2 were of similar quality. When applied to a previously unpublished investigation of lung cancer, the MS1-MS2-combined method increased the coverage of known activated pathways. Since recent technological developments continue to increase the quality of MS1 signals (e.g. using the BoxCar scan mode for Orbitrap instruments), the combination of the MS1 and MS2 information has a high potential for future statistical analysis of DIA data.

Dimethyl phthalate esters (DMPEs) have been identified as endocrine disrupting plastisizers and emerging contaminants which can be released readily upon exposure to the environment. In this study, MWCNTs/TiO2 nanocomposites, which possess the potential application for the photocatalytic degradation of DMPEs under UV irradiation, were prepared via simple one-pot sol-gel reaction using titanium isopropoxide (TTIP) as titania precursor and multiwalled carbon nanotubes (MWCNTs). The MWCNTs/TiO2 nanocomposites was calcined in air for 2 h at the temperatures ranging from 350 to 750 °C. As a result, the MWCNTs/TiO2 nanocomposites synthesized at calcination temperature of 450 °C demonstrated the highest photodegradation efficiency of 97% after 180 min UV irradiation and its degraded products were evaluated using the ultra high performance liquid chromatography (UHPLC) coupled with a high resolution (HR) Orbitrap mass spectrometry (MS). A primary degradation mechanism was proposed and it was noteworthy that some new intermediates were discovered and reported. This work has developed a simple method for qualitative determination of DMPEs based on HPLC with UV detection.

Over the past decade, illicit drugs have been founded in marketed products, which pose a risk to public health. In particular, newly designed analogues synthesized by chemical modification of parent compounds to avoid detection by authorities are frequently detected worldwide. Although many analytical methods for determination of drugs have been reported, analytical methods using high-resolution mass spectrometry, which has the advantage of rapid screening and accurate identification of new substances, are necessary to control illicit drugs in marketed products. In this study, a rapid analytical method using an Orbitrap™ mass spectrometer for identification of illicit drugs in marketed products was developed. The 32 drugs were classified as benzodiazepine-, synthetic cannabinoid-, amphetamine- and benzylpiperazine-type drugs according to their chemical structures, and from their fragmentation patterns in tandem mass spectrometry spectra of an established method. The method validation gave a limit of detection of 0.06–5.30 ng/mL and a limit of quantification of 0.18–16.50 ng/mL, high linearity (R2 > 0.994) and mean recoveries of spiked matrix-blank samples ranging from 83.7% to 117.1%. Approximately 71% of 21 samples collected over 3 years were found to individually contain one of four types of benzodiazepines or two different synthetic cannabinoids. In one case, levels as high as 827.2 mg/g were measured suggesting adulteration at high levels, which suggests that potential illicit products containing drugs should be regularly screened to protect public health.

Highlights • Elabela/Toddler (ELA) is the second endogenous ligand of the apelin receptor identified in zebrafish. • Mature ELA was predicted to be cleaved into [Pyr1]ELA-32, ELA-21 and ELA-11, based on the presence of dibasic amino acid residues. • We have shown that the half-life of [Pyr1]ELA-32 was ∼50 min in human plasma and, Background Elabela/Toddler (ELA) is a novel endogenous ligand of the apelin receptor, whose signalling has emerged as a therapeutic target, for example, in cardiovascular disease and cancer. Shorter forms of ELA-32 have been predicted, including ELA-21 and ELA-11, but metabolism and stability of ELA-32 in humans is poorly understood. We, therefore, developed an LC–MS/MS assay to identify ELA-32 metabolites in human plasma and tissues. Method Human kidney homogenates or plasma were incubated at 37 °C with ELA-32 and aliquots withdrawn over 2−4 h into guanidine hydrochloride. Proteins were precipitated and supernatant solid-phase extracted. Peptides were extracted from coronary artery, brain and kidney by immunoprecipitation or solid-phase extraction following acidification. All samples were reduced and alkylated before analysis on an Orbitrap mass spectrometer in high and nano flow mode. Results The half-life of ELA-32 in plasma and kidney were 47.2 ± 5.7 min and 44.2 ± 3 s, respectively. Using PEAKS Studio and manual data analysis, the most important fragments of ELA-32 with potential biological activity identified were ELA-11, ELA-16, ELA-19 and ELA-20. The corresponding fragments resulting from the loss of C-terminal amino acids were also identified. Endogenous levels of these peptides could not be measured, as ELA peptides are prone to oxidation and poor chromatographic peaks. Conclusions The relatively long ELA plasma half-life observed and identification of a potentially more stable fragment, ELA-16, may suggest that ELA could be a better tool compound and novel template for the development of new drugs acting at the apelin receptor.

Panax notoginseng leaves (PNL) was considered as a potential medicinal part with abundant protopanaxdiol type ginsenosides. In this study, an integrated system was developed for simultaneously qualitative and quantitative analysis of ginsenosides in PNL using online comprehensive two-dimensional hydrophilic interaction chromatography and reversed-phase liquid chromatography coupled to a hybrid linear ion trap-Orbitrap mass spectrometry (online HILIC x RP-ESI/HRMS/MSn). The system was configured based on the combination of a XBridge amide column (150 mm x 2.1 mm, 2.5 mu m) and Accucore phenyl-hexyl (50 mm x 4.6 mm, 2.6 mu m) for the first and second dimensions, respectively. An additional water phase was introduced to dilute the eluent from the first dimension to decrease its elution strength in the second dimension. The online dilution, modulation interface and the second-dimension gradient program were deeply optimized to reduce possible sample loss and improve system resolution. Under the optimal conditions, a total of 226 ginsenosides were unambiguously identified or tentatively characterized by aid of high-resolution accurate mass and MSn fragment data in both negative and positive ion modes, and 93 of them were discovered as potentially new ginsenosides in PNL. Besides, the validated online HILIC x RP-LTQ-MS method was applied to determine 24 ginsenosides directly on 2D-EIC contour plots in nine batches of PNL samples. The powerful separation capability acquired by the developed online HILIC x RP system affords not only reliable structural information for identification, but also accurate quantitation. This combined system can also be used to characterize and quantify bioactive ingredients in the samples with complex matrices. (C) 2019 Elsevier B.V. All rights reserved.

BACKGROUND: Therapeutic drug monitoring (TDM) of antidepressants is important to ensure compliance and to rule out pharmacokinetic abnormalities. Therefore, reliable methods for quantification are important for clinical laboratories. Most of the currently used mass spectrometry methods use triple quadrupoles as mass analyzers. We aimed to develop a method using high-resolution mass spectrometry (HRMS) and wanted to test the suitability of this analyzer for quantitative TDM assays. This would be beneficial since HRMS instruments can also be used for metabolomics and protein analysis and, thus, many different analyses could be run on one instrument. METHODS: After manual protein precipitation of serum samples, further sample clean-up was achieved using a Turbo Flow column preconnected to the analytical LC column. Stable isotope-labelled counterparts of the target analytes were used as internal standards. For detection, we used a Q Exactive Focus Orbitrap mass spectrometer operating in full-scan mode. Ionization was performed in positive ESI. RESULTS: Accuracy, recovery, and matrix effect were acceptable for all analytes. The method demonstrated outstanding precision (within-run imprecision

Liuhuanggou bituminous coal (LBC) and its extraction residue (ER) were thermally dissolved sequentially in cyclohexane, toluene, and ethanol at 300 °C to obtain soluble portions (SPs) 1–3 (SP1-SP3) from the thermal dissolution (TD) In the total yield (TY) of 10.4% and SPs I-III (SPI-SPIII) from the TD in the TY of 4.9%, respectively. The SPs were analyzed by multiple analytical tools, including gas chromatograph/mass spectrometer (GC/MS), quadrupole exactive orbitrap mass spectrometer (QEOTMS), and Fourier transform infrared spectrometer. The analysis with GC/MS shows that normal alkanes are the most abundant in SPI, while arenes are predominant in SP1, SP2, and SPII. According to the analysis with QEOTMS, abundant heteroatom-containing organic species were concentrated into SP3 and SPIII with molecular masses of 150–750 u. The relative contents of N1 and N1O1 species are predominantly high in SPIII and SP3, respectively.

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.

An ultra-high performance liquid chromatography coupled with high-resolution Orbitrap mass spectrometry (UPLC–Orbitrap–MS) method has been used to identify sesquiterpene lactones in the methanolic extract of Centipeda minima. Fifteen sesquiterpene lactones were tentatively identified based on retention time and accurate mass of external standards or exact accurate mass searching (within 2 ppm) by comparison of some previous isolated sesquiterpene lactones. Meanwhile, a rapid, sensitive, precise, and reliable ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-QQQ-MS) method has been developed to evaluate the quality of Centipeda minima through a simultaneous determination of five sesquiterpene lactones, namely brevilin A, arnicolide C, arnicolide D, microhelenin C, minimolide F. Chromatographic separation was achieved on a Waters Acquilty UPLC BEH C18 column (2.1 mm × 50 mm, 1.7 μm) with a mobile phase consisting of a) 0.1% formic acid and b) a mixture of acetonitrile and methanol 50:50 v/v under an isocratic elution (42:58) manner. Positive electrospray ionization mode with multiple reaction monitoring was applied for the detection of the five sesquiterpene lactones. Method validation for linearity, accuracy and precision was also carried out. Finally, the method was successfully used for the analysis of 10 batches of Centipeda minima samples collected in China. Brevilin A and arnicolide D were the dominant sesquiterpene lactones in Centipeda minima and could be proposed as suitable markers for the quality control of Centipeda minima.

The dissipation of famoxadone as well as the behaviour of its metabolites in environmental samples such as water and soil is a major concern. In this study, the dissipation of the target compound in both matrices was carried out applying an analytical method based on ultra-high performance liquid chromatography coupled to Orbitrap mass spectrometry (UHPLC-Orbitrap-MS). The dissipation of famoxadone was monitored over a period of 100 days after the plant protection product, Equation Pro®, was administered to the target matrices. This study was performed at two doses, normal and double in the case of soils and fivefold instead of double dose in water. The concentration of famoxadone steadily decreased during the monitoring period in both matrices. Half-life (DT50) values were lower than 30 days in most cases except for loam soils, for which it was 35 days. Therefore, persistence of this pesticide in both matrices was low. Famoxadone metabolites such as IN-KF015 ((5RS)-5-methyl-5-(4-phenoxyphenyl)-1,3- oxazolidine-2,4-dione) and IN-JS940 ((2RS)-2-hydroxy-2-(4- phenoxyphenyl)propanoic acid) were detected in both matrices and their concentration increased while the concentration of the parent compound decreased. Metabolite IN-JS940 was the compound detected at highest concentration for both matrices. In water the maximum concentration was 20% of the initial famoxadone content and in soils it was 50% of initial famoxadone content. In addition, another metabolite, IN-MN467 ((5RS)-5-methyl-3-[(2-nitrophenyl)amino]- 5-(4-phenoxyphenyl)-1,3-oxazolidine-2,4-dione), was detected in soils, following the same behaviour as the other metabolites. These results provided ample information about the behaviour of metabolites and the necessity of knowing their toxicity in both matrices in order to detect possible risks for living beings.

A generic extraction and UHPLC-Q-Orbitrap™-HRMS method was developed for four insect species (mealworm, grasshopper, house cricket and black soldier fly) analyzing a large spectrum of organic chemical contaminants, including pesticides (n = 25), (veterinary) drugs (n = 29), and mycotoxins (n = 23). To prove the method as 'fit-for-purpose', a successful validation was performed, both qualitatively, by determining the screening detection limit (SDL), selectivity and specificity, as well as semi-quantitatively, by assessing the within-day precision (relative standard deviation (RSD)) and recovery. For both the mealworm, grasshopper, house cricket and black soldier fly, 64, 61, 59 and 62 compounds were detected at the respective SDL levels (1-100 μg kg-1), predominantly below existing maximum residue limits for other edible matrices. Mean recoveries ranged between 70% and 120% and RSD-values were in line with European regulations (CD 2002/657/EC; SANCO). Finally, the potential of the screening methodology was demonstrated on real insect samples, revealing minor to no contamination. ispartof: FOOD CHEMISTRY vol:293 pages:187-196 ispartof: location:England status: published

Lotus plumule, a traditional Chinese medicine, has significant pharmaceutical value to treat various health problems. Flavonoids are important bioactive ingredients in lotus plumule. In this study, we proposed an efficient "fishing" strategy to profile and identify non-targeted flavonoids from lotus plumule aqueous extract based on a self-built mass data "pool" with an untargeted mass data acquisition method in order to acquire comprehensive structural information of flavonoids in lotus plumule. This mass data acquisition method was applied by ultra-high performance liquid chromatography coupled with hybrid quadrupole orbitrap high-resolution mass spectrometry (UHPLC/Q-orbitrap HRMS) executed in full MS/dd-MS2 mode with different collision energies in positive ionization mode. The self-built targeted data "pool" was constructed by the basic structure of flavonoids in lotus plumule, such as odd quasi-molecular ions, C6-C3-C6 skeleton, molecular weight limit. The "molecule lures" of fishing are characterized by molecular features, fragmental patterns, characteristic fragments ions, relative abundance and retention times. More importantly, the special "lures" of PredRet (the tool of predicting the retention times) and ClogP (the calculated lipophilicity parameter) were adopted to distinguish some isomers and some compounds whose mass spectra are difficult to determine with no reference substances. The "fished" flavonoids were further confirmed by their molecular features and fragmental patterns. This developed analysis method was successfully applied to profile 29 flavonoids compounds in the aqueous extract of lotus plumule, and 3 of them were recognized for the first time in lotus plumule. To our knowledge, this is the first analytical screening methods without standard samples to systematically identify flavonoids in lotus plumule.

A Chinese herbal formula of Anti-Renal Interstitial Fibrosis I Decoction (ARIF I) is composed of Eucommia ulmoides Oliv., Scutellaria baicalensis Georgi, and Rheum. officinale Baill., and it has been used for the treatment of chronic kidney disease for many years. However, the comprehensive chemical analysis of the formulated ARIF I has yet to be clarified. In this study, an ultra-high performance liquid chromatography coupled with hybrid quadrupole-orbitrap high resolution mass spectrometry (UHPLC/Q-orbitrap HRMS) method executed in full scan/data-dependent MS2 (full MS/dd-MS2) mode has been established in negative ion mode to analyze the major chemical constituents in ARIF I as well as in its three constituent herbs. To rapidly and efficient identify these compounds, we employed a combination of statistical analysis of the MS2 data and fragmentation pathway method to screen for elementary characteristic ions and sub-characteristic ions. Then, we applied multifold characteristic ion filtering to comprehensively profile ARIF I extract chemical constituents with diverse structures. A total of 360 compounds, including anthraquinones, sennosides, galloyl glucoside derivatives, catechin and its derivatives, flavonoids, iridoids, phenylpropanoids, lignan, organic acid, and other compounds were rapidly identified or tentatively characterized by multifold characteristic ion filtering based on their accurate mass spectra (within 5 ppm error) and structure types or by comparison with reference standards. All the ARIF I compounds were also detected in the individual constituent herbs. This study provides a basis for further pharmacokinetic studies of ARIF I and may help in the discovery of new chemical drugs to treat chronic kidney disease. This study also provides a more efficient approach for the screening of appropriate characteristic ions, and a practical strategy for the detection of the types of compounds identified in this study in other herbal medicines.

Characterization of aqueous extract in traditional Chinese medicine (TCM) is challenging due to the poor retention of the analytes on conventional C18 columns. This study presents a systematic characterization method based on a rapid chromatographic separation (8 min) on a polar-modified C18 (Waters Cortecs T3) column of aqueous extract of Cordyceps sinensis. UHPLC-HRMS method was used to profile components in both untargeted and targeted manners by full MS/PIL/dd-MS2 acquisition approach. The components were identified or tentatively identified by reference standards comparison, fragmentation rules elucidation and available databases search. A total of 91 components, including 10 nucleobases, 20 nucleosides, 39 dipeptides, 18 amino acids and derivatives and 4 other components, were characterized from the aqueous extract of C. sinensis. And this was the first time to systematically report the presence of nucleosides and dipeptides in C. sinensis, especially for modified nucleosides. The chemical basis inquiry of this work would be beneficial to mechanism exploration and quality control of C. sinensis and related products. Meanwhile, this work also provided an effective solution for characterization of aqueous extract in TCM.

Non-targeted small molecule screening methods are used to analyze samples for potential compounds of interest without focusing on specific molecular species. There is great interest in these methods for metabolomic, environmental, forensic, and food safety applications, among others, to determine compounds that are responsible for a particular disease state or the presence of a harmful compound. In order for non-targeted analyses to become standardized and routine, best practices for sample preparation, data collection, and data analysis must be determined. This work focuses on optimizing specific aspects of a non-targeted workflow that utilizes high-resolution mass spectrometry using an Orbitrap instrument coupled to liquid chromatography. Sample preparation, liquid chromatography gradient length, and mass spectrometry resolving power and ionization modes were investigated to determine optimal conditions for detecting and extracting compounds from the data that cover broad molecular and polarity ranges. Infant rice cereal, orange juice, and yogurt with spiked standards were analyzed; food is inherently challenging to analyze due in part to sample complexity and diversity. Of the conditions tested, optimal conditions included a generic sample extraction using acetonitrile, water, and formic acid, a 25 min chromatographic gradient, collecting data in both positive and negative ion modes, and using 70 k resolving power. There are of course tradeoffs associated with each of these options that will be described in detail so that the appropriate conditions can be chosen for the desired application.

Recently, adulterated supplements with phosphodiesterase-5 inhibitors (PDE-5i) have frequently observed. New synthetic analogues obtained from the chemical modification of parent compounds are frequently found in illicit products despite continuous efforts to inspect for these adulterants. A rapid and accurate method based on quadrupole-Orbitrap mass spectrometry was developed for simultaneously confirming and quantifying 85 PDE-5i and derived analogues present in illicit products for erectile dysfunction (ED). Common ions of PDE-5i according to their similar structures were proposed based on MS/MS fragmentations. These common ions could be an important diagnosis of their presence targets or new emerging analogues in supplements. Several validation parameters were employed, resulting in a limit of detection and quantification of 0.09–8.55 ng/mL and 0.24–17.10 ng/mL, respectively. The linear correlation coefficient (r2) was higher than 0.995, and mean recoveries of target compounds were in the range of 82–118%. A total of 187 illicit products, obtained from on/offline markets over a period of 3 years (2015–2017), were screened by the established method. Approximately 53% of them were adulterated with PDE-5i or derived analogues at concentrations of 0.1–726.0 mg/g in the illicit products. In the interests of public health, this study describes a rapid and accurate method to determine PDE-5i and new emerging analogues in adulterated products.

High-performance liquid chromatography (HPLC) and linear-ion trap (LTQ)/Orbitrap high-resolution mass spectrometry were used to identify porcine gelatins extracted at different temperatures. Moreover, shear stress rheological detection techniques and a texture analyzer were applied to evaluate the gelling properties of various porcine gelatins. The results showed that, with an increased in the extraction temperature, the gel strength, gelation point and melting point of the porcine gelatin gradually decreased, indicating that the temperature significantly affected the gelling properties of gelatin. HPLC- LTQ/Orbitrap high-resolution mass spectrometry indicated that porcine gelatins prepared at different extraction temperatures also showed internal uniqueness, namely, diverse marker peptides for gelatin identification. Compared with the established theoretical sequence fragment database of porcine gelatin and bovine gelatin, 64, 74 and 71 tryptic porcine peptides in gelatins were extracted at 55 °C, 65 °C and 75 °C, respectively. Notably, regardless of the extraction temperature, 47 common peptides were detected in the tryptic hydrolysates of porcine gelatins. Using these common tryptic peptides can effectively improve the accuracy of the porcine gelatin identification.

Walnut (Juglans regia L.) is an abundant source of polyphenols. Although phenolic species in the walnut kernel have been studied comprehensively, their compositional profile in the internal fruit septum, a traditional nutraceutical material in China, has been rarely explored. In the current study, the methanolic extract of the walnut septum was analysed by Ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry. Totally seventy-five phenolics belonging to flavonoids, tannins and phenolic acids were identified based on mass spectra, references and literatures. Among them, quercetin-3-O-galactoside, quercetin-rhamnose-pentoside, quercetin-3-O-glucoside, quercetin-rhamnose-hexoside, kaempferol-rhamnoside, and two isomers of quercetin-rhamnoside were reported for the first time in walnut. The total polyphenol content was found to be 122.78 ± 2.55 mg GAE/g dry weight in septum. This study is the first to comprehensively investigate and identify phenolic compounds in the fruit septum of walnut and indicates that the septum to be a rich resource of polyphenols.

Classification and characterization of agricultural products at molecular levels are important but often impractical with genotyping, particularly for soybeans that have numerous types of variety and landraces. Alternatively, metabolic signature, a determinant for nutritional value, can be the good molecular indicator, which reflects cultivation region-dependent factors such as climate and soil. Accordingly, we analyzed the integrative metabolic profiles of Korean soybeans cultivated in 7 different provinces (representative production areas), and explored the potential association with geographic traits. A total of 210 primary and secondary metabolites were profiled using gas-chromatography time-of-flight mass spectrometry (GC-TOF MS) and liquid-chromatography Orbitrap mass spectrometry (LC-Orbitrap MS). Despite the partial heterogeneity of the soybean varieties, the metabolomic phenotypic analysis based on multivariate statistics inferred the chemical compositional characteristics was primarily governed by the regional specificity. The OPLS-DA model proposed biomarker cluster re-composed with 5 metabolites (tryptophan, malonylgenistin, malonyldaidzin, N-acetylornithine, and allysine) (AUCs = 0.870–1.0). The most distinctive metabolic profiles were identified with the soybeans of Gunsan (middle-western coast) and Daegu (east-southern inland area), which were best characterized by the highest contents of isoflavones and amino acids, respectively. Further interrogation on geographic data suggested the combinatorial association of region-specific metabolic features with general soil texture and climate traits (total rainfall and average annual temperature).

Benzimidazoles (BZDs) are widely used veterinary drugs in the domestic food-producing animals, resulting in the metabolism of BZDs and the harmful metabolites residues in some foods. However, some BZD metabolites are unknown and so it is important to discover new metabolites to expand detection targets. For these reasons, a sensitive and selective strategy was designed to identify BZD metabolites in the serum of pigs after oral administration of albendazole, fenbendazole and thiabendazole, respectively. Nickel oxide nanoparticle-deposited silica (SiO2@NiO) composite was used for the enrichment and purification of BZD compounds. High-performance liquid chromatography coupled with precursor ion scan-mass spectrometry (LC-PIS-MS) and high resolution MS/MS analysis (HR-MS/MS) was employed for the BZDs metabolic profiles characterization and metabolites detection. Finally, 18 BZD metabolites were identified, among which 11 metabolites were discovered in pig serum for the first time. Besides, more comprehensive BZD metabolic pathways were presented.

Asphaltenes cause multiple problems in the petroleum industry, such as clogging crude oil transportation pipelines and fouling catalysts. Characterization of the structures of the compounds in asphaltenes is essential for addressing these problems. Two main categories of asphaltene molecular structures, single-core (island) and multicore (archipelago), have been agreed upon. However, their relative abundances in asphaltenes have been debated for decades. This may be partially due to the fact that many mass spectrometry studies carried out in both academia and industry make conclusions for the entire asphaltene sample based on information derived from a group of ionized asphaltenes with m/z values ranging from one up to ten. This approach makes the unvalidated assumption that the relative abundances of single- and multicore compounds are uniform within the entire sample. In this study, medium-energy collision-activated dissociation (MCAD) in a linear quadrupole ion trap/orbitrap high-resolution mass spectrometer was employed to explore the structures of asphaltene molecular ions with m/z values in the ranges of 350 ± 10, 450 ± 10, 550 ± 10 and 650 ± 10. The ions studied displayed different extents of decrease in their weighted average ring and double bond equivalence (RDBE) values when undergoing dissociation, suggesting that the abundances of single-core and multicore compounds are not uniform within the entire asphaltene samples. Therefore, traditional mass spectrometry approaches used to determine the relative abundances of single- and multicore asphaltene compounds may suffer from a sampling bias. However, in-source collision-activated dissociation (IS-CAD) is not susceptible to sampling bias because no ion selection is involved.

N-nitrosodimethylamine (NDMA) is a disinfection byproduct that has been classified as probable human carcinogen by the US Environmental Protection Agency. According to the published literature, natural dissolved organic matter (DOM) can be a source of NDMA precursors in drinking water. New advances in chemical characterization of DOM with high resolution mass spectrometry (HRMS) are allowing researchers to understand these ultra-complex mixtures. The objective of this study is to investigate analytical methodologies based on HRMS to explore NDMA formation from natural waters. To this aim, different waters from drinking water reservoirs in Spain containing NDMA precursors (quantified by means of NDMA formation potential) in concentrations between 17 and 60 ng/L have been studied. The workflow includes DOM solid-phase extraction and Orbitrap analysis with and without chromatographic separation. Here, we show that the molecular composition of DOM across the studied drinking water reservoirs is correlated with the NDMA formation potential. In particular, we found that NDMA formation potential is associated with compounds with high hydrogen saturation (H/C ≥ 1.5), corresponding also to reservoirs with higher background nutrient concentrations and wastewater indicators. Further chromatographic fractionation did not allow better definition of these possible precursors as they were present in different fractions of the chromatogram, suggesting that they were isomerically complex.

Ingestion of hypoglycin A (HGA) in maple seeds or alkaloids produced by symbiotic fungi in pasture grasses is thought to be associated with various syndromes in grazing animals. This article describes analytical methods for monitoring long-term exposure to HGA, its metabolite MCPA-carnitine, as well as ergocristine, ergocryptine, ergotamine, ergovaline, lolitrem B, N-acetylloline, N-formylloline, peramine, and paxilline in equine hair. After extraction of hair samples separation was achieved using two ultra high performance liquid chromatographic systems (HILIC or RP-C18, ammonium formate:acetonitrile). A benchtop orbitrap instrument was used for high resolution tandem mass spectrometric detection. All analytes were sensitively detected with limits of detection between 1 pg/mg and 25 pg/mg. Irreproducible extraction or ubiquitous presence in horse hair precluded quantitative validation of lolitrem B/paxilline and N-acetylloline/N-formylloline, respectively. For the other analytes validation showed no interferences in blank hair. Other validation parameters were as follows: limits of quantification (LOQ), 10 to 100 pg/mg; recoveries, 18.3 to 91.0%; matrix effects, -48.2 - 24.4%; linearity, LOQ - 1000 pg/mg; accuracy, -14.9 - 6.4%, precision RSDs ≤10.7%. The method allows sensitive detection of all analytes and quantification of ergocristine, ergocryptine, ergotamine, ergovaline, HGA, MCPA-carnitine, and peramine in horse hair. Applicability was proven for N-acetylloline and N-formylloline by analyzing hair of 13 horses.

As high-production-volume chemicals, chlorinated paraffins (CPs) have raised an increasing environmental concern in recent years. However, their accurate analysis and quantification is still a huge challenge due to the high complexity of their technical formulations and the interference from CPs congeners and other polychlorinated products. In this study, a novel method for the simultaneous analysis of short-chain (SC) and medium-chain (MC) CPs in a single injection has been developed using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry (UHPLC-Orbitrap Fusion TMS). Compared with other analytical methods for CPs, this novel method can greatly shorten the measurement time and provides a lower limit of detection. A high resolution of 120,000 FWHM was set to avoid the self-interference of CPs congeners and to eliminate interferences from chlorinated olefins (COs). Accuracies for SCCPs and MCCPs standards were evaluated at 75-103% and 83-118%, respectively. The developed method was further validated by determining CPs in sediment, soil, and indoor dust samples. This novel method gives higher CPs concentrations than those achieved by gas chromatography-electron capture negative ionization low-resolution mass spectrometry (GC-ECNI-LRMS), with factors of 1.1-12.5 for SCCPs and 0.7-2.7 for MCCPs, respectively. Some new CPs, such as C8Cl7-8 and C9Cl5-8, have been determined in soil samples for the first time, indicating great potential of this novel method for routine CP analysis in various environmental samples.

Considerable effort and progress has been made over the past decade with respect to development of analytical tools for the determination of naphthenic acids and related components in environmental samples. However, experimental variables that influence the analytical results have not been fully explored. The relative contributions of Ox classes are of particular interest in data obtained using negative-ion electrospray ionization mass spectrometry. Using two types of ultrahigh resolution mass spectrometers (Orbitrap and FT-ICR), the apparent pH of the transfer solvent was observed to have a significant impact upon compound class distributions. A basic transfer solvent favored the detection of Ox species of lower oxygen content, while acidic pH favored the preferential observation of organic compounds with higher oxygen contents. These observed trends were independent of the instrument type. In addition, when using an acidic transfer solvent, the overall observed response was reduced by a factor of ∼20. Thus, the apparent pH of the transfer solvent has critical influence upon detection and upon the profile of different components observed within a complex mixture. In turn, this significantly impacts oil sands environmental monitoring for toxicity, forensic interpretation, and quantitation; when comparing data sets from different laboratories, these findings should therefore be taken into account.

In recent years, liquid crystal displays (LCDs) became more and more popular in industrial and consumer electronics applications. Unevenly distributed liquid crystals (LC) and the presence of organic contaminations in the LC layer, for example from the display sealant, can cause display defects and therefore lower the display quality. This work describes the development of a fast and easy screening method for display samples by laser ablation coupled to atmospheric pressure chemical ionization-mass spectrometry (LA-APCI-MS). With this ambient technique, LC components as well as sealant materials, which are one of the main sources for display contaminations, can be detected simultaneously using spatial resolutions down to 100 μm. Minimal sample preparation is needed for this method and exact masses can be acquired by using an Orbitrap mass analyzer. By LA-APCI-MS, nineteen different LCs and five different sealant materials were detected as pure substances as well as on commercially available LCDs. In addition, a principle component analysis (PCA) was used to differentiate between LCs and sealant ions in the complex data matrix.

Taking into consideration of the cytotoxicity and topo-IIα inhibitory activity of pyrazoline derivatives (1-3) against HCT15 cells, and known topo-IIα inhibitor, etoposide, respectively, the compounds were biotransformed in rat liver microsomes. LC-MS/MS and MALDI mass spectrometric techniques has been used for analysis. All three compounds were biotransformed into demethylated metabolites. Among three compounds, compounds 1 and 2 were biotransformed into mono-hydroxylated metabolites and compound 3 biotransformed into reduced and epoxidized metabolites. Reduced and reduced along with demethylation metabolites were identified from MALDI Orbitrap spectrometric analysis. Without NADPH or microsomes no compounds (1-3) were generated metabolites, it shows CYP450 enzymes involvement in the presence of NADPH in the metabolisms.

The present work addresses the detailed structural elucidation by high resolution techniques of both liquid pyrolysis products from slow pyrolysis of crambe seeds. Bio-oil and aqueous phase were obtained at 400 °C with 32% and 15.8% (w/w) yield and were separated by density difference. Lyophilization was applied to concentrate the organic compounds present in aqueous phase (OCAP). Bio-oil and the OCAP were analyzed by comprehensive bidimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) and positive and negative-ion electrospray (ESI) high resolution Orbitrap mass spectrometry (HRMS). For the bio-oil, 1,400 analytes were identified by GC×GC-TOFMS and the most abundant classes were hydrocarbons (448.6 mg g−1) and N-containing compounds (172.2 mg g−1). In the bio-oil ESI-(+) Orbitrap HRMS data, the N2 class was the most abundant (79.9%). In the negative mode, ca. 87.6% of assigned peaks corresponded to O2 class for bio-oil. The major compounds identified by GC×GC-TOFMS in the OCAP were oxygenated (49.8%) and NO containing compounds (45.9%). ESI (−) Orbitrap HRMS analysis for OCAP presented high percentage of O2 (57.2%) and NO (28.3%) classes, while ESI (+) Orbitrap MS of N2 (51.8%) and NO (28.8%) classes. The aqueous fraction composition profile indicates a potential biological activity due to the presence of N-heterocyclic compounds and the bio-oil (38.9 MJ kg−1; 5.4% H2O) has the potential to be used as a second generation (ASTM D7544) or hydrotreated to improve fuel quality.

A new, relatively simple sample processing and detection workflow has been developed for the quantification and confirmation of banned growth-promoting substances in a wide variety of animal-based food products. The method covers all required compounds (belonging to the so-called A1, A3, A4 and B2f groups as termed by the relevant EU legislation) which are currently monitored by the official European community surveillance programs. The sample processing includes a thermal sample denaturation step, intended to prevent undesirable side-reactions during the following enzymatic deconjugation of covalently bound analytes. A pH-adjusted dual liquid/liquid-extraction produces sufficient clean extracts for a wide range of matrices (urine, muscle, liver, serum, full blood). The method has been validated using two hybrid quadrupole high-resolution mass spectrometers (Orbitrap and time-of-flight technology-based instruments). Full-scan data acquisition, interlaced with targeted modes (unit mass isolation of the precursors, followed by collision-induced fragmentation), produces sufficiently sensitive and selective detection of the analytes within all the validated matrices. The proposed method is an alternative to currently used methods that are restricted to a limited set of analytes and matrices.

Baiyinhua lignite (BL) was sequentially treated in cyclohexane, CH3OH, CH3CH2OH, and (CH3)2CHOH at 300 °C to afford soluble portions (SPs) 1–4 (SP1–SP4), which were analyzed with a Fourier transform infrared spectrometer, gas chromatograph/mass spectrometer (GC/MS), and quadrupole exactive orbitrap mass spectrometer (QEOTMS) with atmosphere pressure chemical ionization source in negative-ion mode. In addition, it was characterized with a solid-state 13C nuclear magnetic resonance and X-ray photoelectron spectrometer (XRPES). The results show that aliphatic and aromatic carbons, accounting for 37.1% and 59.2%, respectively, are dominated in BL. Each aromatic cluster contains 2 rings on average with 3 substituent groups on each ring. According to the analysis with XRPES, –OH group is the most abundant existing form of oxygen in BL. The analysis with GC/MS shows that the most abundant group components are arenols in SP1 and SP2, and alkanoates in SP3. Thousands of oxygen-containing aromatics (OCAs) were resolved with the QEOTMS and the molecular masses are mainly in the range of 250–400 μ. The main OCAs detected are O1–O6 class species, dominated by O2–O5 class species, which could be mainly assigned to acidic species, such as alkylarenediols, alkylarenetriols, and alkylarenoic acids.

An analytical methodology for comprehensive screening of 63 coloring agents of great concern for regulatory control in cosmetics has been established using ultra-high-performance liquid chromatography (UHPLC) coupled with quadrupole-Orbitrap high-resolution mass spectrometry (Q-Orbitrap HRMS). An effective, rapid, and simple sample pretreatment protocol with low sample and reagent consumption was developed based on matrix solid-phase dispersion (MSPD). The selection of the most suitable extraction conditions was made using statistical tools of factorial multifactor experimental design and analysis of variance (ANOVA). In the final conditions, 0.1 g of cosmetic sample was blended with 0.3 g of anhydrous sodium sulfate and 0.4 g of sand, and the MSPD column was eluted with 2 mL of methanol. The extract was analyzed by UHPLC-Q-Orbitrap HRMS under synchronous full-scan MS and data-dependent MS/MS (full-scan MS1/dd-MS2) acquisition mode. The mass resolution was set to 70,000 FWHM (full width at half maximum) for full-scan MS1 and 17,500 FWHM for dd-MS2 stage with the experimentally measured mass deviations of less than 3 ppm (parts per million) for quasi-molecular ions and 5 ppm for characteristic fragment ions for each individual analyte. An accurate-mass database and a mass spectral library were built in house for searching the 63 target compounds. Broad screening was conducted by comparing the experimentally measured exact mass of precursor and fragment ions, retention time, isotopic pattern, and ionic ratio with the accurate-mass database and by matching the acquired MS/MS spectra against the mass spectral library. Method performance was evaluated in terms of limits of detection (LODs), limits of quantitation (LOQs), linearity, precision, recovery, and matrix effect. The UHPLC-Q-Orbitrap HRMS approach was applied for the simultaneous analysis of 63 target coloring agents in 69 genuine cosmetic samples. Eleven legally prohibited coloring agents were detected in 26 cosmetic samples in total. The proposed method exhibited great potential for high-throughput, sensitive, and reliable screening of multi-class coloring agent substances in cosmetics.

This study reports an analytical method for simultaneous identification, screening and quantification of 164 residues and metabolites of pharmacologically active substances belonging to such therapeutic classes as anti-infectious (antibiotics and chemotheurapeutics), anti-inflammatory and antiparasitic agents (against protozoa, endo- and ectoparasites), corticoids and agents acting on the nervous and reproductive systems, substances with hormonal and thyreostatic action, and beta agonists. Different sample preparation procedures were compared and optimised for the detection of selected veterinary drugs in chicken, porcine and bovine meat by ultra-high performance liquid chromatography coupled to high-resolution Orbitrap mass spectrometry. The optimised instrumental method and sample preparation procedures were validated by fortifying blank matrix at four levels (0.5, 1.0, 1.5, and 2 times the maximum residue limit (MRL)), or at concentrations as low as possible for substances without an MRL. The evaluated performance parameters were selectivity, matrix effect, method and instrument limits of quantification, accuracy, and repeatability. A total of 130 selected compounds in chicken meat, 127 compounds in bovine meat and 123 compounds in porcine meat samples could be quantified with accuracy ranging from 70 to 120% and RSDs less than 30%. Finally, the method was successfully used to detect and quantify veterinary drug residues in real samples found to be suspect using the non-selective qualitative test for the detection of inhibitor substances. The results were confirmed using the relevant one-residue confirmatory methods revealing concentrations of residues higher than MRLs established for several samples.

The analytical capability of the UPLC-Q Exactive™ Orbitrap MS was exploited for simultaneous determination of 30 acidic and basic PPCPs in a single run, using rapid polarity switching of the electrospray ionisation source. Full scan MS mode at resolution of 35,000 FWHM, Automatic gain control (AGC) target of 1E6 ions at injection time of 50 ms provided the optimum parameters for high sensitivity, together with sufficient data points per peak (≥15) for improved reproducibility. In addition to chromatographic retention times, method selectivity was achieved via applying high resolution accurate mass with low mass tolerance filter ( 0.95) were established for all target analytes over a concentration range of 1–1500 ng/ml. Good results were obtained for method accuracy (% recovery = 76–104%), inter- and intra-day precision (relative standard deviation

Analysis of mycotoxins in functional and medicinal herbs is a challenge because herbs have complicated and diverse matrices from different parts of plants as well as different species. Here, we introduce a rapid and comprehensive liquid chromatography–tandem mass spectrometry method for the determination of multi-class mycotoxins (aflatoxin B1, B2, G1, G2, ochratoxin A, zearalenone, deoxynivalenol, fumonisin B1, B2, B3 and T-2 toxin) in twenty different species of herbs that are used for both food and medicinal purposes. Various sample preparation methods were compared and optimized to obtain satisfactory extraction of mycotoxins in different matrices. The extraction efficiency was found to vary from not only extraction methods but also matrix types, demonstrating the complexity of herbal matrix. On the basis of optimization results, immunoaffinity column was selected as an extraction method to cover all types of samples. QuEChERS was also employed as a supplementary method to support the immunoaffinity column method. The developed method was validated by assessing specificity, linearity, precision, recovery, limit of quantification and uncertainty, and applied in a hundred of real samples to monitor target mycotoxins. The monitoring results were further verified using accurate high resolution mass measurements by Orbitrap mass spectrometry. As far as we know, this is the first time the multi-class mycotoxins were determined in a broad range of functional and medicinal herb matrices, with high selectivity and sensitivity. In addition, the proposed method was proven to be more efficient and sensitive than other methods.

A new sensitive and selective multi-residue method based on liquid chromatography - Orbitrap high resolution mass spectrometry (LC-Orbitrap-HRMS) was developed and validated for the determination of 17 anticoccidials in poultry and eggs. Instrumental parameters were optimized by the means of statistical experimental designs to improve the sensitivity, precision, and repeatability of the method. Further optimization of auto-tuned MS parameters led to an increase of signal intensity by 10% to 99% for 16 out of 17 analytes. The sample preparation procedure included extraction from muscle tissue and egg samples with acetonitrile, followed by preconcentration, reconstitution, and filtration. Validation was performed according to the Commission Decision 2002/657/EC. The occurrence of anticoccidials in eggs and poultry was assessed by using the developed analytical procedure within the Latvian national monitoring program, revealing quantifiable residues for 6 analytes (marker residue of nicarbazin - 4,4'-dinitrocarbanilide (DNC), salinomycin, narasin, toltrazuril, and its two metabolites).

Plasticizers and other plastics additives have been extensively used as ingredients of plastics and are as a result thereof easily released in the aquatic environment, due to different physical diffusion processes. In this context, a dedicated method was developed for the simultaneous quantification of 27 known and a virtually unlimited number of unknown alkylphenols, Bisphenol A and phthalates in 2 aquatic matrices, i.e. sea- and freshwater. To this extent, a novel instrumental HESI-UHPLC-HRMS (heated electro-spray ionization ultra-high performance liquid chromatographic high resolution mass spectrometric) method was devised for the simultaneous analysis of 7 phenols (i.e. 6 alkylphenols and Bisphenol A) and 20 phthalates within 10 min. Thereafter, a solid-phase extraction protocol was statistically (95% confidence interval, p > 0.05) optimized based on experimental designs. The method was proven fit-for-purpose through a successful validation at environmentally relevant nanomolar concentrations. Analytical precautions were taken for minimizing false-positive results to suppress in-house contamination. The method demonstrated an excellent analytical performance across all known plasticizers and plastics additives for sea- and freshwater, revealing good linearity (R2 > 0.99, n = 39), stable recoveries (98.5–105.8%), satisfactory repeatability (RSD

Human milk is a dynamic protein-protease system that delivers bioactive peptides to infants. The pH of milk changes from the mother’s mammary gland to the infant’s digestive tract. Although the release of human milk peptides has been studied during in vivo or in vitro digestion, these models did not explicitly vary nor observe the effect of pH. The objective of this research was to determine the effect of pH on the proteolysis of human milk. Using high-resolution accurate-mass Orbitrap mass spectrometry, profiles of endogenous human milk peptides before and after incubation at various pH levels have been mapped. Over 5000 peptides were identified. Comparative analyses classified 74 peptides that were consistently found independent of pH alterations, and 8 peptides that were released only at pH 4 or 5 (typical infant gastric pH). Results documented that the proteolysis of milk proteins, particularly β-casein, polymeric immunoglobulin receptor, and α-lactalbumin, is pH-dependent.

The current study was aimed to investigate the synthesis and self-assembly of cellulose nanofibrils in in vitro environment through intermediate phase analysis and compare with the microbial cell system. The presence and stability of cellulose synthase and other essential enzymes were qualitatively validated through liquid chromatography–mass spectrometry/mass spectrometry linear trap quadrupole (LC–MS/MS LTQ) Orbitrap analysis of the culture medium after each batch (15 days’ point) of in vitro incubation. Monitoring of bio-cellulose synthesis in the in vitro environment revealed that β-1,4-glucan chains were de novo synthesized within the culture medium which crystallized and formed the premature bio-cellulose and bio-cellulose pellicles. The pellicle moved to the surface of the medium and ultimately formed a bio-cellulose sheet at the air-medium interface. In contrast to aerobic synthesis of cellulose (bacterial cellulose) by microbial cells, bio-cellulose was synthesized anaerboically by the cell-free enzyme system and the thickness of the sheet at the air-medium interface increased from the bottom surface facing the culture medium as confirmed by the field-emission scanning electron microscopy (FE-SEM). The current study will provide a base for in situ development of bionanocomposites of cellulose with various bactericidal and polymeric materials for broad spectrum applications.

A coal was extracted and thermally dissolved with cyclohexane, acetone and methanol sequentially. The ultrasonic extracts and thermal dissolution (TD) products were analyzed using an Orbitrap mass spectrometer (MS) with an atmospheric pressure chemical ionization source in positive ion mode. Large amounts of MS data were obtained but there were challenges in obtaining meaningful information from the data. The purpose of cluster analysis is to reduce complex multivariate data into meaningful groups. Two cluster analysis methods, hierarchical cluster analysis and expectation maximum algorithm based on Gaussian mixture model (EMGM), run by R language were introduced to obtain in-depth statistical results for compounds in both extracts and TD products. Seven types of heteroatomic compounds (O1, O2, N1, S1, O1N1, O1S1 and N1S1) in the extracts under the condition of ultrasonic extraction with cyclohexane were clustered with EMGM and possible structures of the related models can be inferred by analyzing the relationship between carbon number and double bond equivalent. The application of cluster analysis will provide methodological guidance in studying the structure of coal molecules.

Soy-based burgers, an option of meatless hamburger-style, are basically made with soy protein, wholegrains and veggies. However, some ingredients, such as cereals and soybean, are particularly susceptible to fungal contamination. Therefore, a fast and simple procedure for the simultaneous determination of isoflavones (n=12) and mycotoxins (n=21) in soy-based burgers was developed throughout an acetonitrile-based extraction and UHPLC-Q-Exactive Orbitrap HRMS determination for the first time. The procedure was properly validated in terms of linearity, accuracy (recovery range from 78 to 108%) and precision (RSD

The prospect of developing new bio-based products from lignin partially depends on the development of effective analytical techniques to characterize the end products from lignin degradation experiments. To date, the most utilized mass spectrometric technique for characterizing lignin oligomers has been negative ion mass spectrometry. Positive ion mass spectrometry remains a relatively unexplored approach for lignin sequencing. Here we report on the sequencing of lignin oligomers using lithium cationization positive ion electrospray followed by higher-energy collisional dissociation (HCD) tandem mass spectrometry on a high-resolution accurate-mass Orbitrap mass spectrometer. Thirteen synthetic lignin model oligomers containing β-O-4 and 4-O-α linkages were analyzed and sequenced based on their HCD tandem mass spectrometry fragmentation patterns. Proposed sequence-specific fragmentation pathways are provided. The method presented in this study provides a potential application of lithium cationization tandem mass spectrometry for the analysis of lignin degradation products.

Identification of pyrolysis intermediates and products is of great significance to better understanding of a pyrolysis process and therefore its further upgrade to practical fuels. We hereby report a real-time analysis of pyrolysis volatiles of biomass in a micro fixed-bed reactor via an on-line near-atmospheric pressure photoionization Orbitrap mass spectrometry (nAPPI Orbitrap MS). The mass spectra suggest the pyrolysis products bear a molecular weight in the range of m/z 50–300. The oxygenated compounds having between 1 and 5 oxygen atoms and with double bond equivalent (DBE) values ranging from 2 to 7 account for more than 90% of the identified peaks, indicating that significant upgrading should be developed towards applications. Pyrolysis products could be clearly distinguished from different components of biomass in the van Krevelen diagrams and DBE versus carbon number plots. The results from the nAPPI Orbitrap MS are further compared to those of off-line pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) and on-line single photoionization mass spectrometry (SPI-MS). The nAPPI Orbitrap MS is a powerful on-line approach with high sensitivity, ultrahigh-resolution, and no condensation or preparation. This analytical protocol is expected to be helpful in complicated thermochemical conversion studies, e.g. pyrolysis of biomass.

A novel kind of macro-mesoporous organosilica monolith, with not only bridged-ethylene groups incorporated into the skeleton but also terminal-vinyl groups protruded from the pore-wall, was prepared so that high-loaded double bonds were achieved. Via highly efficient “thiol-ene” click reaction of such high-loaded double bonds, the surface coverage of C18 groups on monolith could be 5.54 μmol m−2, significantly larger than that of the reported separation materials, beneficial to improvement of separation resolution, especially for peptide separation. The separation performance was evaluated using alkylbenzenes and standard peptides. Furthermore, the tryptic digests of complex sample was successfully analyzed. Because of high separation resolution of our prepared hybrid monolith, the peak capacity for 6-h gradient was achieved as 482. Coupling to LTQ Orbitrap Velos Mass Spectrometry, 22523 tryptic peptides from 4423 proteins were identified from the HeLa cells, more than that using the other long-gradient separation by the same system reported, showing great promising of such monolith for large-scale in-depth proteomic analysis.