Ultrahigh Resolution Mass Spectrometry Research Articles

Discovery of Polar Ozonation Byproducts via Direct Injection of Effluent Organic Matter with Online LC-FT-ICR-MS.

Effluent organic matter (EfOM), a major ozone consumer during wastewater ozonation, is a complex mixture of natural and anthropogenic organic molecules. Ozonation of EfOM adds to molecular complexity by introducing polar and potentially mobile ozonation byproducts (OBPs). Currently, nontargeted direct infusion (DI) ultrahigh resolution mass spectrometry (e.g. FT-ICR-MS) is used to study OBPs but requires sample extraction, limiting the accessible polarity range of OBPs. To better understand the impact of ozonation on EfOM and the formation of polar OBPs, nonextracted effluent was analyzed by direct injection onto a reversed-phase liquid chromatography system (RP-LC) online hyphenated with an FT-ICR-MS. Over four times more OBPs were detected in nonextracted EfOM compared to effluent extracted with solid phase extraction and measured with DI-FT-ICR-MS (13817 vs 3075). Over 1500 highly oxygenated OBPs were detected exclusively in early eluting fractions of nonextracted EfOM, indicating polar OBPs. Oxygenation of these newly discovered OBPs is higher than previously found, with an average molecular DBE-O value of -3.3 and O/C ratio of 0.84 in the earliest eluting OBP fractions. These polar OBPs are consistently lost during extraction but may play an important role in understanding the environmental impact of ozonated EfOM. Moreover, 316 molecular formulas classified as nonreactive to ozone in DI-FT-ICR-MS can be identified with LC-FT-ICR-MS as isomers with varying degrees of reactivity, providing for the first time experimental evidence of differential reactivity of complex organic matter isomers with ozone.

Molecular Characterization of Dissolved Black Carbon-Like Molecules Along the Pearl River Estuary China in Summer by Ultrahigh Resolution Mass Spectrometry

Molecular Characterization of Dissolved Black Carbon-Like Molecules Along the Pearl River Estuary China in Summer by Ultrahigh Resolution Mass Spectrometry

Molecular Insights into the Transformation Mechanisms of Dissolved Organic Matter Based on Ultrahigh Resolution Mass Spectrometry

Molecular Insights into the Transformation Mechanisms of Dissolved Organic Matter Based on Ultrahigh Resolution Mass Spectrometry

Characterization of Biochar-Derived Organic Matter Extracted with Solvents of Differing Polarity Via Ultrahigh-Resolution Mass Spectrometry

Characterization of Biochar-Derived Organic Matter Extracted with Solvents of Differing Polarity Via Ultrahigh-Resolution Mass Spectrometry

Electromembrane Extraction for Analysis of Naphthenic Acids in Produced Water by Ultrahigh-Resolution Mass Spectrometry

Electromembrane Extraction for Analysis of Naphthenic Acids in Produced Water by Ultrahigh-Resolution Mass Spectrometry

Biostimulants in Dissolved Organic Matters Recovered from Anaerobic Digestion Sludge with Alkali-Hydrothermal Treatment: Nontarget Identification by Ultrahigh-Resolution Mass Spectrometry

Biostimulants in Dissolved Organic Matters Recovered from Anaerobic Digestion Sludge with Alkali-Hydrothermal Treatment: Nontarget Identification by Ultrahigh-Resolution Mass Spectrometry

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.

Thermal Studies of Aqueous Free-Base Porphyrin and Metalloporphyrins of Cu, Ag and Mn

Present study is intended on the thermal behaviour of the free base aqueous porphyrin and the corresponding metalloporphyrins of some of the transition metal ions such as Cu, Ag and Mn. The respective porphyrins were synthesized and characterized by ultra violet-visible spectroscopy, infrared spectroscopy and high-resolution mass spectrometry. These porphyrins thus obtained were then subjected to thermal analysis from room temperature to 800 ºC. It was observed that free-base porphyrin tetrasodium meso-tetra (p-sulphonatophenyl) porphyrin (TPPS4) is stable up to 360 ºC and remaining metalloporphyrins are stable in the range of 435-460 ºC, respectively. Further, the hygroscopic porphyrins were subjected to fixation of number of water molecules of crystallization and quantitative analysis with respect to % of metal oxide, % of Na+, % SO4 2- and % coal respectively.

Molecular Characterization of Nitrogen-Containing Compounds in Humic-like Substances Emitted from Biomass Burning and Coal Combustion.

N-containing organic compounds (NOCs) in humic-like substances (HULIS) emitted from biomass burning (BB) and coal combustion (CC) were characterized by ultrahigh-resolution mass spectrometry in the positive electrospray ionization mode. Our results indicate that NOCs include CHON+ and CHN+ groups, which are detected as a substantial fraction in both BB- and CC-derived HULIS, and suggest that not only BB but also CC is the potential important source of NOCs in the atmosphere. The CHON+ compounds mainly consist of reduced nitrogen compounds with other oxygenated functional groups, and straw- and coal-smoke HULIS exhibit a lower degree of oxidation than pine-smoke HULIS. In addition, the NOCs with higher N atoms (N2 and/or N3) generally bear higher modified aromaticity index (AImod) values and are mainly contained in BB HULIS, especially in straw-smoke HULIS, whereas the NOCs with a lower N atom (N1) always have relatively lower AImod values and are the dominant NOCs in CC HULIS. These findings imply that the primary emission from CC may be a significant source of N1 compounds, whereas high N number (e.g., N2-3) compounds could be associated with burning of biomass materials. Further study is warranted to distinguish the NOCs from more sources.

Data-Based Chemical Class Regions for Van Krevelen Diagrams.

Ultrahigh resolution mass spectrometry (UHR-MS) is commonly used to characterize natural organic matter (NOM). The complexity of both NOM and the data set produced make data visualization challenging. Van Krevelen diagrams─plots of component hydrogen/carbon (H/C) against oxygen/carbon (O/C) elemental ratios─have become a popular way to visualize the chemical formulas identified by UHR-MS. Different regions on the van Krevelen diagram have been attributed to different chemical classes; however, the classifications vary between studies and the regions lack standard definitions. Here, chemical formulas were obtained from public databases to create H/C and O/C ranges for amino sugar, carbohydrate, lignin, lipid, peptide, and tannin chemical classes on van Krevelen diagrams. The recommended H/C and O/C ranges are presented in a table and can be adapted to any data analysis software programs. The regions recommended here agreed reasonably well with previous literature for amino sugar, carbohydrate, lignin, lipid, and peptide regions. However, the recommended tannin region appears at lower H/C ratio values and with a wider range of O/C ratio values compared to previous studies. The regions presented herein are strongly recommended for use as consistent reference points in future NOM characterization studies to aid in the discussion of data and to readily compare studies.

Direct Imaging of Plant Metabolites in the Rhizosphere Using Laser Desorption Ionization Ultra-High Resolution Mass Spectrometry.

The interplay of rhizosphere components such as root exudates, microbes, and minerals results in small-scale gradients of organic molecules in the soil around roots. The current methods for the direct chemical imaging of plant metabolites in the rhizosphere often lack molecular information or require labeling with fluorescent tags or isotopes. Here, we present a novel workflow using laser desorption ionization (LDI) combined with mass spectrometric imaging (MSI) to directly analyze plant metabolites in a complex soil matrix. Undisturbed samples of the roots and the surrounding soil of Zea mays L. plants from either field- or laboratory-scale experiments were embedded and cryosectioned to 100 μm thin sections. The target metabolites were detected with a spatial resolution of 25 μm in the root and the surrounding soil based on accurate masses using ultra-high mass resolution laser desorption ionization Fourier-transform ion cyclotron resonance mass spectrometry (LDI-FT-ICR-MS). Using this workflow, we could determine the rhizosphere gradients of a dihexose (e.g., sucrose) and other plant metabolites (e.g., coumaric acid, vanillic acid). The molecular gradients for the dihexose showed a high abundance of this metabolite in the root and a strong depletion of the signal intensity within 150 μm from the root surface. Analyzing several sections from the same undisturbed soil sample allowed us to follow molecular gradients along the root axis. Benefiting from the ultra-high mass resolution, isotopologues of the dihexose could be readily resolved to enable the detection of stable isotope labels on the compound level. Overall, the direct molecular imaging via LDI-FT-ICR-MS allows for the first time a non-targeted or targeted analysis of plant metabolites in undisturbed soil samples, paving the way to study the turnover of root-derived organic carbon in the rhizosphere with high chemical and spatial resolution.

Yeast interaction on Chardonnay wine composition: Impact of strain and inoculation time

It is of great importance to understand the molecular characteristics and substantial chemical transformations due to yeast-yeast interaction. Non-targeted metabolomics was used to unravel must in fermentation composition, inoculated with non-Saccharomyces (NS) yeasts and Saccharomyces cerevisiae (S) for sequential fermentation. ultrahigh-resolution mass spectrometry was able to distinguish thousands of metabolites and provides deep insights into grape must composition allowing better understanding of the yeast-yeast interactome. The dominance of S, characterized by a metabolic richness not found with NS, is dependent on inoculation time and on the yeast species present. Co-inoculation leads to the formation of new compounds, reflecting a reshuffling of yeast metabolism linked to interaction mechanisms. Among the modifications observed, metabolomic unravels deep changes in nitrogen metabolism due to yeast-yeast interactions and suggests that the redistribution pattern affects two different routes, the pentose phosphate and the amino acid synthesis pathways.

Metabolism and cytotoxicity of diphenylarsinic acid, a degradation product of sea-dumped chemical warfare agents, in a rainbow trout liver cell line RTL-W1.

Recent studies have found primary degradation products of phenylarsenic chemical warfare agents (CWAs) accumulating in fish tissues, while the potential effects of these dumped phenylarsenic CWAs, such as Clark I and II, in the Baltic Sea biota are poorly understood. In this study, the metabolism and cytotoxicity of diphenylarsinic acid (DPA), a primary degradation product of phenylarsenic CWA, was studied by incubating rainbow trout cell line RTL-W1 cells in media with 100mg/L DPA. Previously undescribed metabolites were identified by ultra-high performance liquid chromatography-high resolution mass spectrometry (UPHLCHRMS). Moreover, the cytotoxicity of diphenylarsine glutathione conjugate (DPA-SG), the major metabolite of DPA, was studied. Cytotoxicity of the compounds was evaluated using the Neutral Red retention test (NRR), showing an IC50 value of 278mg/L for DPA and 1.30mg/L for DPA-SG, indicating that the glutathione (GSH) conjugate of DPA is more than two orders of magnitude toxic than DPA itself, suggesting that toxic properties of DPA are increased after conjugation with intracellular GSH leading enhanced toxicity after uptake. Results gained in this study give more detailed information for elucidating biological effects of dumped chemical munitions in marine environment. Moreover, the results help in assessing the environmental and health risks posed by marine munition continued presence and deterioration in the sea bottom.

Molecular diversity of liquid digestate from anaerobic digestion plants for biogenic waste

The treatment and valorization of liquid digestate (ADLD) after anaerobic digestion of biogenic waste are challenging. This study used ultra-high resolution mass spectrometry to determine the molecular characteristics of ADLD collected from different full-scale plants for food waste treatment. The results indicated that there were regular differences in the dissolved organic matter (DOM) indicators among the samples from dry and wet anaerobic processes. ADLD DOM had higher H/C and O/C, and contained more easily degradable proteins. In addition, sCOD and pH were the drivers of the molecular distribution of ADLD common compounds. The same common compounds were present in the ADLD from different anaerobic digestion plants. They had a significant correlation with physicochemical characteristics. The compounds relating to plant hormones and nutrients as well as xenobiotics were both identified, suggesting that comprehensive considerations should be taken into account for the land application of ADLD.

Analytical Insights into the Microstructures and Reaction Mechanisms of Cationic Pd(II) α-Diimine-Catalyzed Polyolefins

A combination of ultrahigh resolution mass spectrometry (MS), MS/MS fragmentation, nuclear magnetic resonance spectroscopy (NMR), and computational chemistry was used to probe the reaction mechanis...

Elucidation of the non-volatile fingerprint in oven headspace vapor from bread roll baking by ultra-high resolution mass spectrometry

Untargeted research on vapor arising during the thermal processing of food has so far focused on volatile aroma compounds. In this study, we present an oven atmosphere sampling strategy to trap headspace aerosols along with semi- and non-volatile molecules liberated during the baking of wheat bread rolls. The collected vapor condensate was analyzed for its molecular fingerprinting using direct infusion ultra-high resolution mass spectrometry. We detected up to 4,700 molecular species in a vapor sample from bread rolls baked at 230 °C for 15 min. Beyond the global profiling of the underlying matrix, our method can follow complex reaction cascades during the baking process, such as the formation of advanced glycation end-products like maltosine through the interface of trapped vapor. Further, process parameters such as baking temperature and duration were used to model the dynamic liberation of molecules to the oven atmosphere by a response surface methodology approach.

Selecting Processing Robust Markers Using High-Resolution Mass Spectrometry for the Detection of Milk in Food Products.

Cow's milk allergy is one of the most reported food allergies in Europe. To help patients suffering from food allergies it is important to be able to detect milk in different foods. An analytical method that is gaining interest in the field of allergen detection is ultrahigh performance liquid chromatography-tandem mass spectrometry, where the analyte is a target peptide. When these peptide biomarkers are selected, the effect of food processing should be taken into account to allow a robust detection method. This work aims at identifying such processing stable peptide markers for milk for the ultrahigh performance liquid chromatography-tandem mass spectrometry based detection of food allergens in different food products. Milk-incurred food materials that underwent several processing techniques were produced. This was followed by establishing tryptic peptide profiles from each matrix using ultrahigh performance liquid chromatography-high resolution mass spectrometry. A careful comparison of peptide profiles/intensities and the use of specific exclusion criteria resulted in the selection of eight peptide biomarkers suitable for application in ultrahigh performance liquid chromatography-tandem mass spectrometry based milk detection methods. One of these markers is an α-lactalbumin specific peptide, which has been determined to be stable in different incurred materials for the first time. To our knowledge, this is the first systematic and experimentally based approach for the selection of suitable milk peptide biomarkers robust toward multiple, often applied food processing techniques for milk. Ensuring the exact knowledge of the food processing circumstances by starting from well-defined raw material and using fully controlled settings to produce incurred test material allowed the construction of a peptide database with robust markers. These robust markers can be used for the development of a robust detection method for milk in different food matrixes. To facilitate food allergen detection in processed food, processing stable peptide markers for the detection of milk in food products were determined using Ultra-High Performance Liquid Chromatography-High Resolution Mass Spectrometry on well-defined raw materials which were processed in accordance with often used processing techniques.

Dissolved organic matter production from herder application and in-situ burning of crude oil at high latitudes: Bioavailable molecular composition patterns and microbial community diversity effects

Chemical herders and in-situ burning (ISB) are designed to mitigate the effects that oil spills may have on the high latitude marine environment. Little information exists on the water solubilization of petroleum residues stemming from chemically herded ISB and whether these bioavailable compounds have measurable impacts on marine biota. In this experiment, we investigated the effects of Siltech OP40 and crude oil ISB on a) petroleum-derived dissolved organic matter (DOMHC) composition and b) seawater microbial community diversity over 28 days at 4 °C in aquarium-scale mesocosms. Ultra-high resolution mass spectrometry and fluorescence spectroscopy revealed increases in aromaticity over time, with ISB and ISB+OP40 samples having higher % aromatic classes in the initial incubation periods. ISB+OP40 contained a nearly 12-fold increase in the number of DOMHC formulae relative to those before ISB. 16S rRNA gene sequencing identified differences in microbial alpha diversity between seawater, ISB, OP40, and ISB+OP40. Microbial betadiversity shifts were observed that correlated strongly with aromatic/condensed relative abundance and incubation time. Proteobacteria, specifically from the genera Marinomonas and Perlucidibaca experienced −22 and +24 log2-fold changes in ISB+OP40 vs. seawater, respectively. These findings provide an important opportunity to advance our understanding of chemical herders and ISB in the high latitude marine environment.

Analysis of Five Mushroom Toxins in Blood by UPLC-HRMS.

To develop a method for the simultaneous and rapid detection of five mushroom toxins (α-amanitin, phallacidin, muscimol, muscarine and psilocin) in blood by ultra-high performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). The blood samples were precipitated with acetonitrile-water solution(Vacetonitril∶Vwater=3∶1) and PAX powder, then separated on ACQUITY Premier C18 column, eluted gradient. Five kinds of mushroom toxins were monitored by FullMS-ddMS2/positive ion scanning mode, and qualitative and quantitative analysis was conducted according to the accurate mass numbers of primary and secondary fragment ions. All the five mushroom toxins had good linearity in their linear range, with a determination coefficient (R2)≥0.99. The detection limit was 0.2-20 ng/mL. The ration limit was 0.5-50 ng/mL. The recoveries of low, medium and high additive levels were 89.6%-101.4%, the relative standard deviation was 1.7%-6.7%, the accuracy was 90.4%-101.3%, the intra-day precision was 0.6%-9.0%, the daytime precision was 1.7%-6.3%, and the matrix effect was 42.2%-129.8%. The method is simple, rapid, high recovery rate, and could be used for rapid and accurate qualitative screening and quantitative analysis of various mushroom toxins in biological samples at the same time, so as to provide basis for the identification of mushroom poisoning events.

Molecular characterization of the composition and transformation of dissolved organic matter during the semi-permeable membrane covered hyperthermophilic composting

Current knowledge of dissolved organic matter (DOM) in semi-permeable membrane-covered thermophilic compost (smHTC) is limited. Therefore, this study provided a comprehensive characterization of composition and transformation of DOM in smHTC using multiple spectroscopic methods and ultrahigh resolution mass spectrometry. The results showed that the values of SUVA280, SUVA254, A240‐400 (0.042, 0.048, 34.193) in smHTC were higher than those of conventional thermophilic composting (cTC) (0.030, 0.037, 18.348), and the increment of PV,n in smHTC were 2.4 times higher than that of cTC. These results suggested that smHTC accelerated the humification process by promoting the degradation of labile DOM and the production of humus-like substances. Mass spectrometry further confirmed that the DOM of smHTC possessed higher degree of aromatization and humification, based on the lower H/C (1.14), higher aromaticity index (0.34) and double bond equivalence (10.36). Additionally, smHTC increased the proportion of carboxyl-rich, unsaturated and aromatic compounds, and simultaneously improved the degradation of aliphatic/proteins, lipids, carbohydrates, along with even some refractory substances such as CHO subcategory (24.1%), especially lignin-like structures (14.8%). This investigation provided molecular insights into the composition and transformations of DOM in smHTC, and extended the current molecular mechanisms of humification in composting.