Electrospray Ionization Fourier Transform Ion Research Articles

Structure and composition of dissolved organic matters in sludge by ultrasonic treatment

The leaching of dissolved organic matter (DOM) from the sludge into the liquid phase is induced by ultrasound. However, there is limited investigation into the structure and molecular composition of sludge DOM in this process. The molecular structure and composition of sludge DOM in ultrasonic treatment were comprehensively elucidated in this study. The sludge dissolved organic carbon (DOC) and three-dimensional fluorescence spectroscopy (3D-EEM) image had most significant change at 15-min ultrasonic time and 1.2 W/mL ultrasonic density, respectively. Gas Chromatography-Mass Spectrometry (GC-MS) analysis indicated that ultrasonic treatment of sludge reduced the macromolecules to small molecules in DOM. Then, electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS) analysis revealed that lignin, tannins, and carbohydrates were the main components of sludge DOMs after ultrasound treatment. analysis revealed that lignin, tannins, and carbohydrates were the main components of sludge DOMs after ultrasound treatment. Furthermore, through the Van Krevelen analysis, the major components were CHO (48.50%) and CHOS (23.20%) in the DOM of ultrasonicated sludge. This research provides the basis for the practical application of ultrasonic treatment of sludge and provides basic information for DOM components.

Photolysis of Dissolved Organic Matter over Hematite Nanoplatelets.

Solar photoexcitation of chromophoric groups in dissolved organic matter (DOM), when coupled to photoreduction of ubiquitous Fe(III)-oxide nanoparticles, can significantly accelerate DOM degradation in near-surface terrestrial systems, but the mechanisms of these reactions remain elusive. We examined the photolysis of chromophoric soil DOM coated onto hematite nanoplatelets featuring (001) exposed facets using a combination of molecular spectroscopies and density functional theory (DFT) computations. Reactive oxygen species (ROS) probed by electron paramagnetic resonance (EPR) spectroscopy revealed that both singlet oxygen and superoxide are the predominant ROS responsible for DOM degradation. DFT calculations confirmed that Fe(II) on the hematite (001) surface, created by interfacial electron transfer from photoexcited chromophores in DOM, can reduce dioxygen molecules to superoxide radicals (•O2-) through a one-electron transfer process. 1H nuclear magnetic resonance (NMR) and electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) spectroscopies show that the association of DOM with hematite enhances the cleavage of aromatic groups during photodegradation. The findings point to a pivotal role for organic matter at the interface that guides specific ROS generation and the subsequent photodegradation process, as well as the prospect of using ROS signatures as a forensic tool to help interpret more complicated field-relevant systems.

Mechanistic Insights into the Biodegradation of Carbon Dots by Fungal Laccase.

While carbon dots (CDs) have the potential to support the agricultural revolution, it remains obscure about their environmental fate and bioavailability by plants. Fungal laccase-mediated biotransformation of carbon nanomaterials has received little attention despite its known capacity to eliminate recalcitrant contaminants. Herein, we presented the initial investigation into the transformation of CDs by fungal laccase. The degradation rates of CDs were determined to be first-order in both substrate and enzyme. Computational docking studies showed that CDs preferentially bonded to the pocket of laccase on the basal plane rather than the edge through hydrogen bonds and hydrophobic interactions. Electrospray ionization-Fourier transform-ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS) and other characterizations revealed that the phenolic/amino lignins and tannins portions in CDs are susceptible to laccase transformation, resulting in graphitic structure damage and smaller-sized fragments. By using the 13C stable isotope labeling technique, we quantified the uptake and translocation of 13C-CDs by mung bean plants. 13C-CDs (10 mg L-1) accumulated in the root, stem, and leaf were estimated to be 291, 239, and 152 μg g-1 at day 5. We also evidenced that laccase treatment alters the particle size and surface chemistry of CDs, which could facilitate the uptake of CDs by plants and reduce their nanotoxicity to plants.

Molecular insights into the impacts of acid mine drainage on dissolved organic matter dynamics in pit lakes

Pit lakes are artificial hydrological features created by mining operations that typically suffer from acid mine drainage (AMD), which not only endangers water quality but also exacerbates carbon loss. However, the impacts of AMD on the fate and role of dissolved organic matter (DOM) in pit lakes remain unclear. This study employed negative electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) combined with biogeochemical analysis to examine DOM molecular variations and environmental controls across the AMD-induced acidic and metalliferous gradients in five pit lakes. The results demonstrated distinct DOM pools in pit lakes characterized by the prevalence of smaller aliphatic compounds compared to other waterbodies. AMD-induced geochemical gradients promoted DOM heterogeneity among pit lakes, with acidic pit lakes containing more lipid-like compounds. Acidity and metals enhanced DOM photodegradation, reducing the content, chemo-diversity and aromaticity. Organic sulfur was detected in high abundance, potentially from sulfate photo-esterification and mineral flotation agent. Furthermore, microbial involvements in carbon cycling were revealed by DOM-microbe correlation network, but microbial contributions to the DOM pools decreased under acidic and metal stresses. These findings highlight abnormal carbon dynamics caused by AMD pollution and integrate DOM fate into pit lake biogeochemistry, thereby contributing to management and remediation.

Presence of aromatic-rich organic matter and its characterization in grout materials: Implications for radionuclide immobilization

Grout materials are commonly used to immobilize low-level radioactive waste. Organic moieties can be unintentionally present in common ingredients used to make these grout waste forms, which may result in the formation of organo-radionuclide species. These species can positively or negatively affect the immobilization efficiency. However, the presence of organic carbon compounds is rarely considered in models or characterized chemically. Here, we quantify the organic pool of grout formulations with and without slag, as well as the individual dry ingredients used to make the grout samples (ordinary Portland cement (OPC), slag and fly ash), including total organic carbon (TOC) and black carbon, followed by aromaticity evaluation and molecular characterization via Electro Spray Ionization Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (ESI-FTICRMS). All dry grout ingredients contained significant amounts of organic carbon, ranging from 550 mg/kg to 6250 mg/kg for the TOC pool, with an averaged abundance of 2933 ± 2537 mg/kg, of which 60 ± 29% was composed of black carbon. The significant abundance of a black carbon pool implies the presence of the aromatic-like compounds, which was further identified by both phosphate buffer-assisted aromaticity evaluation (e.g., >1000 mg-C/kg as aromatic-like carbon in the OPC) and dichloromethane (DCM) extraction with ESI-FTICRMS analysis. Besides aromatic-like compounds, other organic moieties were also detected in the OPC, such as carboxyl-containing aliphatic molecules. While the organic compound only consists of minor fractions of the grout materials investigated, our observations of the presence of various radionuclide-binding organic moieties suggests the potential formation of organo-radionuclides, such as radioiodine, which might be present at lower molar concentrations than TOC. Evaluating the role of organic carbon complexation in controlling the disposed radionuclides, especially for those radionuclides with strong association with organic carbon, has important implications for the long-term immobilization of radioactive waste in grout systems.

Molecular characterization of humic-like substances (HULIS) in atmospheric particles (PM2.5) in offshore Eastern China Sea (OECS) using solid-phase extraction coupled with ESI FT-ICR MS

Humic-like substances (HULIS) are organic macromolecular compounds (water-soluble brown carbon) that have an important effect on climate change due to their strong light absorption. However, the molecular composition of HULIS in atmospheric particles in the offshore Eastern China Sea (OECS) has scarcely been investigated. In this study, solid-phase extraction (SPE) was performed to collect HULIS from water extracts. The molecular compositions of samples were characterized by negative-ion electrospray ionization (ESI) Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). A total of 1197–1828 molecular formulas of HULIS were identified in collected samples, and three of them with higher intensities near Shanghai city, Zhejiang province, and Fujian province were discussed in detail. The identified molecular formulas were classified into four major subgroups, including CHO, CHNO, CHOS, and CHNOS compounds. S-containing formulas (CHOS and CHNOS) represented the dominant components (21.0–76.7% relative abundance), followed by CHO (16.5–64.3%), while CHNO compounds constituted 6.1–18.1% of the identified formulas. High fractions of CHO formulas were found in the list of α-pinene ozonolysis yields and S-containing formulas with olefinic structures were abundant in atmospheric particles, suggesting enhanced SOA formation. The samples had a relative abundance-weighted average O/C of 0.25–0.67 and a double bond equivalent of 3.49–4.96. Most identified formulas (>89%) were assigned to aliphatic and olefinic species. The CHNO and S-containing formulas identified in the samples were primarily contributed by –ONO2 functional groups and organosulfates. Biogenic volatile organic compounds (α-pinene or monoterpene) were the dominant precursors of HULIS in the samples. Lignin-like species (41–46%) and protein/amino sugars (28–30%) were the major species among substance classes. The results provide an improved understanding of the molecular composition of HULIS in the Eastern China Sea.

Characterization of Sequentially Extracted Soil Organic Matter by Electrospray Ionization and Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Characterization of Sequentially Extracted Soil Organic Matter by Electrospray Ionization and Atmospheric Pressure Photoionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Comparison of Sample Preparation Techniques for the (−)ESI-FT-ICR-MS Analysis of Humic and Fulvic Acids

Soil organic matter (SOM) plays a key role in the global carbon and nitrogen cycles. Soil biogeochemistry is regularly studied by extracting the base-soluble fractions of SOM: acid-insoluble humic acid (HA) and acid-soluble fulvic acid (FA). Electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry (ESI-FT-ICR-MS) is commonly utilized for molecularly characterizing these fractions. Different sample preparation techniques exist for the analysis of HA and FA though questions remain regarding data comparability following different preparations. Comparisons of different sample preparation techniques here revealed that the negative-mode ESI-FT-ICR-MS analytical window can be skewed to detect different groups of molecules, with primary differences in oxygenation, aromaticity, and molecular weight. It was also observed that HA and FA from soils versus an aquatic matrix behaved very differently. Thus, we conclude that sample preparation techniques determined to be "most optimal" in our study are in no way universal. We recommend that future studies of HA and FA involve similar comparative studies for determining the most suitable sample preparation technique for their particular type of HA or FA matrices. This will enhance data comparability among different studies and environmental systems and ultimately allow us to better understand the complex composition of environmental matrices.

Lycorine Alkaloid and Crinum americanum L. (Amaryllidaceae) Extracts Display Antifungal Activity on Clinically Relevant Candida Species

Candida species are the main fungal agents causing infectious conditions in hospital patients. The development of new drugs with antifungal potential, increased efficacy, and reduced toxicity is essential to face the challenge of fungal resistance to standard treatments. The aim of this study is to evaluate the in vitro antifungal effects of two crude extracts of Crinum americanum L., a rich alkaloid fraction and lycorine alkaloid, on the Candida species. As such, we used a disk diffusion susceptibility test, determined the minimum inhibitory concentration (MIC), and characterized the components of the extracts using Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR MS). The extracts were found to have antifungal activity against various Candida species. The chemical characterization of the extracts indicated the presence of alkaloids such as lycorine and crinine. The Amaryllidaceae family has a promising antifungal potential. Furthermore, it was found that the alkaloid lycorine directly contributes to the effects that were observed for the extracts and fraction of C. americanum.

Unsupervised Structural Classification of Dissolved Organic Matter Based on Fragmentation Pathways.

Dissolved organic matter (DOM) is considered an essential component of the Earth's ecological and biogeochemical processes. Structural information of DOM components at the molecular level remains one of the most extraordinary analytical challenges. Advances in determination of chemical formulas from the molecular studies of DOM have provided limited indications on structural signatures and potential reaction pathways. In this work, we extend the structural characterization of a wetland DOM sample using precursor and fragment molecular ions obtained by a sequential electrospray ionization-Fourier transform-ion cyclotron resonance tandem mass spectrometry (ESI-FT-ICR CASI-CID MS/MS) approach. The DOM chemical complexity resulted in near 900 precursors (P) and 24 000 fragment (F) molecular ions over a small m/z 261-477 range. The DOM structural content was dissected into families of structurally connected precursors based on neutral mass loss patterns (Pn-1 + F1:n + C) across the two-dimensional (2D) MS/MS space. This workflow identified over 1900 structural families of DOM compounds based on a precursor and neutral loss (H2O, CH4O, and CO2). The inspection of structural families showed a high degree of isomeric content (numerous identical fragmentation pathways), not discriminable with sole precursor ion analysis. The connectivity map of structural families allows for the visualization of potential biogeochemical processes that DOM undergoes throughout its lifetime. This study illustrates that integrating effective computational tools on a comprehensive high-resolution mass fragmentation strategy further enables the DOM structural characterization.

Molecular Characterization of NSO Compounds and Paleoenvironment Implication for Saline Lacustrine Oil Sands by Positive-Ion Mass Spectrometry Coupled with Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry.

NSO compounds mainly exist in geological bodies in the form of nonhydrocarbons and asphaltenes with abundant geological and geochemical information. Combined with the gas chromatography mass spectrometry (GC–MS) technology, positive-ion electrospray ionization Fourier-transform ion cyclotron resonance MS (FT-ICR MS) was used to understand the composition and distribution characteristics of NSO compounds in the oil sands of the Dongpu Depression and to explore their paleoenvironmental significance. The results show that n-alkanes are characterized by an even carbon number and phytane dominance, suggesting a saline lacustrine environment. Certain abundance of nC37 and β-carotane, high gammacerane content, and low diasterane content are detected in the analyzed samples, reflecting the saline-reducing paleoenvironment for the organic matter. Nine types of heteroatom compounds are detected: N1, N1O1, N1S1, O1, O1S1, O2, O2S1, S1, and S2. The main compounds are S1 and N1 compounds, followed by O1S1 compounds. The double-bond equivalent (DBE) value of S1 compounds is mainly distributed between 3 and 12, and the carbon number is mainly distributed between 18 and 35. The DBE value of N1 compounds is mainly distributed between 4 and 14, and the carbon number is mainly distributed in the range 15–35. Among the S1 compounds, DBE3 compounds (thiophenes) have relatively more sulfur-containing carotenoids (C40). The abundance of C40 S1 and the ratio of pyridine and its homologue DBE4–8/DBE9–12 N1 compounds show a good contrast with the paleoenvironment indicators of gammacerane/C30 hopane and diasterane/regular sterane. They can be used as a reference for the paleoenvironment index. Maturity is another factor affecting the distribution of NSO heteroatoms in the oil sands. NSO compounds are enriched in the DBE area with higher condensation, and the main peak carbon shifts forward. As the maturity increases, the relative abundance of N1 compounds increases, the aromatization intensifies, and carbon is broken into short chains. The research results shed light on the potential application of NSO compounds in petroleum exploration based on FT-ICR MS.

Molecular Level Characterization of Diatom and Coccolithophore-Associated Biopolymers That Are Binding 210Pb and 210Po in Seawater

Through a combination of selective extractions and molecular characterization techniques including Isoelectric Focusing Chromatography and Electrospray Ionization Fourier-Transform Ion Cyclotron Resonance Mass spectrometry, molecular structures of diatom (Phaeodactylum tricornutum) and coccolithophore (Emiliania huxleyi)-associated biopolymers that are responsible for the distinct partitioning behavior between 210Pb and 210Po were determined. Our results show that diatom-derived biopolymers have distinctive elemental grouping distributions as compared to those excreted by the coccolithophore, with the former consisting of more heterogeneous elements (i.e., nitrogen, sulfur and phosphorus-containing organic compounds). For the coccolithophore culture, two 210Pb-enriched biopolymers (non-attached exopolymeric substances and coccosphere shell-associated biopolymers) have a higher abundance of CHO-type compounds, suggesting CHO-only-type compounds as the main binding moieties for 210Pb. In contrast, such association was not evident in the diatom culture. Different with 210Pb, 210Po enrichment in coccolithophore-derived attached exopolymeric substances and Fe-Mn-associated metabolites coincided with the higher abundance of nitrogen/sulfur-containing organic compounds in these two biopolymer fractions, suggesting the strong parallel of Po with the production of nitrogen-rich organic matter as well as sulfur-containing amino acids. These different associations between 210Pb/210Po and organic functional groups were further explored by separating 210Pb or 210Po-labeled coccolithophore-derived biopolymers via isoelectric focusing. This technique suggests that phosphate group-containing molecules but not the other molecules that contain heterogeneous elements (e.g., CHONS, CHON, and CHOS) as the strongest binding agents for 210Pb, while the more hydrophobic (high protein to carbohydrate ratio) nitrogen/sulfur-enriched organic moieties acted as the main 210Po-binding ligands. It is concluded that the deficiency of 210Po with respect to 210Pb can be influenced by the relative abundance of nitrogen/sulfur-enriched organic moieties to the nitrogen/sulfur-depleted organic compounds in the water column. This behavior constrains the application of 210Po-210Pb approach to quantify the particulate organic carbon (POC) export flux in the ocean. It also explains that differences in chemical binding of the 210Po as compared to those of other radionuclides (e.g., thorium-234) as the main factor. That suggests that differences in decay half-lives or physical factors are less important when these nuclides are applied to estimate the POC flux in the ocean.

Bioprospecting of Natural Compounds from Brazilian Cerrado Biome Plants in Human Cervical Cancer Cell Lines.

Cervical cancer is the third most common in Brazilian women. The chemotherapy used for the treatment of this disease can cause many side effects; then, to overcome this problem, new treatment options are necessary. Natural compounds represent one of the most promising sources for the development of new drugs. In this study, 13 different species of 6 families from the Brazilian Cerrado vegetation biome were screened against human cervical cancer cell lines (CCC). Some of these species were also evaluated in one normal keratinocyte cell line (HaCaT). The effect of crude extracts on cell viability was evaluated by a colorimetric method (MTS assay). Extracts from Annona crassiflora, Miconia albicans, Miconia chamissois, Stryphnodendron adstringens, Tapirira guianensis, Xylopia aromatica, and Achyrocline alata showed half-maximal inhibitory concentration (IC50) values < 30 μg/mL for at least one CCC. A. crassiflora and S. adstringens extracts were selective for CCC. Mass spectrometry (Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (ESI FT-ICR MS)) of A. crassiflora identified fatty acids and flavonols as secondary compounds. One of the A. crassiflora fractions, 7C24 (from chloroform partition), increased H2AX phosphorylation (suggesting DNA damage), PARP cleavage, and cell cycle arrest in CCC. Kaempferol-3-O-rhamnoside and oleic acid were bioactive molecules identified in 7C24 fraction. These findings emphasize the importance of investigating bioactive molecules from natural sources for developing new anti-cancer drugs.

Dissolved Organic Matter in Continental Hydro-Geothermal Systems: Insights from Two Hot Springs of the East African Rift Valley

Little is known about the quantity and quality of dissolved organic matter (DOM) in waters from continental geothermal systems, with only a few reports available from the Yellowstone US National Park. In this study, we explored the chemodiversity of DOM in water samples collected from two geothermal hot springs from the Kenyan East African Rift Valley, a region extremely rich in fumaroles, geysers, and spouting springs, located in close proximity to volcanic lakes. The DOM characterization included in-depth assessments performed by negative electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Reduced, saturated and little aromatic DOM compounds were dominant in the hot spring waters collected from either the Ol Njorowa gorge (ON) or the south shore of the soda-saline Lake Elementaita (ELM). Oxygen-poor and sulfur-bearing DOM molecules prevailed in ON, probably reflecting abiotic sulfurization from sulfide-rich geofluids. Nitrogen-bearing aliphatic and protein-like molecules were abundant in ELM, possibly perfusing through the organic-rich sediments of the adjacent Lake Elementaita. Notably, the heat-altered DOM of ancient autochthonous derivation could represent an overlooked source of aliphatic organic carbon for connected lentic environments, with a potential direct impact on nutrient cycling in lakes that receive geothermal water inputs.

Compositional Differences in Dissolved Organic Matter Between Arctic Cold Seeps Versus Non-Seep Sites at the Svalbard Continental Margin and the Barents Sea

Dissociating gas hydrates, submerged permafrost, and gas bearing sediments release methane to the water column from a multitude of seeps in the Arctic Ocean. The seeping methane dissolves and supports the growth of aerobic methane oxidizing bacteria (MOB), but the effect of seepage and seep related biogeochemical processes on water column dissolved organic matter (DOM) dynamics is not well constrained. We compared dissolved methane, nutrients, chlorophyll, and particulate matter concentrations and methane oxidation (MOx) rates from previously characterized seep and non-seep areas at the continental margin of Svalbard and the Barents Sea in May and June 2017. DOM molecular composition was determined by Electrospray Ionization Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We found that the chemical diversity of DOM was 3 to 5% higher and constituted more protein- and lipid-like composition near methane seeps when compared to non-seep areas. Distributions of nutrients, chlorophyll, and particulate matter however, were essentially governed by the water column hydrography and primary production. We surmise that the organic intermediates directly derived from seepage or indirectly from seep-related biogeochemical processes, e.g., MOx, modifies the composition of DOM leading to distinct DOM molecular-level signatures in the water column at cold seeps.

Ion Suppression of Basic Nitrogen Compounds in Vacuum Gas Oil Studied by Positive Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Ion suppression or matrix effect has been widely concerned because of its influence on the characterization of electrospray ionization mass spectrometry. A clear understanding about the ion suppres...

Pyrolysis Temperature Effect on Compositions of Neutral Nitrogen and Acidic Species in Shale Oil Using Negative-Ion ESI FT-ICR MS.

Negative-ion electrospray ionization (ESI) Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to study the effect of the pyrolysis temperature (400, 430, 460, 490, and 520 °C) on acidic and neutral nitrogen species in Huadian shale oil. To more accurately analyze the influence, shale oils produced during the heat-up stage were abandoned. The results show that because of the influence of polymerization and cracking reactions, the increase in temperature increases the content of pyrrole, thiophene, furan, phenol, and aromatic ring cores and decreases the content of carboxylic acid, respectively. Among all the heteroatom compounds identified from negative-ion ESI FT-ICR MS, the relative abundance of N1O1, N1O2, N1O3, N2, N2O1, O1, O3, O1S1, and N1S1 species increases, whereas that of O2 and O4 species decreases as the pyrolysis temperature increases. The decrease in the O2 species can be attributed to carboxylic acid with a double-bond equivalence (DBE) value of 1, whereas the increase in the O2 species with DBE values of 7 and 9 can be attributed to the formation of furan, phenol, and aromatic ring by the polymerization reaction at higher pyrolysis temperatures. Although the effect of the reaction temperature on the molecular composition of acidic and neutral nitrogen species is complex, still characteristic rules are found in this study.

Molecular Absorption and Evolution Mechanisms of PM2.5Brown Carbon Revealed by Electrospray Ionization Fourier Transform–Ion Cyclotron Resonance Mass Spectrometry During a Severe Winter Pollution Episode in Xi'an, China

AbstractKnowledge of the molecular‐level chemistry of brown carbon (BrC) is important in reducing the uncertainties in aerosol radiative forcing. Time‐resolved ambient PM2.5samples were collected during a severe pollution episode in January 2017 over Xi'an, China for a comprehensive nontarget and full scanning of BrC molecules and their absorption properties using electrospray ionization Fourier transform–ion cyclotron resonance mass spectrometry combined with partial least squares regression analysis, which apportioned the overall ultraviolet absorption to individual molecules. The estimated absorption of CHNO and CHNOS molecules exhibited nighttime prevalence, whereas CHOS, CHNS, CHN, CHO, CHS, and CH molecules presented a dynamic trend. Carbon conjugation was positively correlated with estimated absorption by CHO and CHNO molecules, while exhibiting a mixed relationship with CHNOS. Higher nitrogen content was associated with enhanced light‐absorption properties of BrC molecules, while higher oxygen and sulfur content appeared to be associated with photobleaching during secondary transformation.

Metabolic profiling of different wild and cultivated Allium species based on high-resolution mass spectrometry, high-performance liquid chromatography-photodiode array detector, and color analysis.

Many plants of the genus Allium are widely cultivated and consumed for their nutraceutical and health-enhancing bioactive components effective in many metabolic and infectious diseases. In particular, Allium sativum L. (garlic), the most economically important Allium species, is known to present volatile, comparatively polar sulfur-containing compounds responsible for both the typical garlic aroma and antimicrobial property. More recently, the (moderately) polar portion of garlic metabolome, rich of polyphenols and amino acids, is gaining increasing interest as a source of antioxidants and primary nutrients. In this study, we have explored the chemical diversity of eight different hydroalcoholic extracts obtained by microwave-assisted extraction of white and red crop A. sativum and wild Allium triquetrum, Allium roseum, and Allium ampeloprasum, all originating from the Mediterranean Basin. The aim is to appraise their potential dietetic and healing value through an in-depth chemical characterization and contribute to preserve and exploit natural resources. The multimethodological method applied here is based on an untargeted metabolic profiling by means of high-resolution electrospray ionization Fourier-transform ion cyclotron resonance (ESI FT-ICR) mass spectrometry. More than 850 by ESI(+) and 450 by ESI(-) putative metabolites have been annotated covering all main classes of primary and secondary metabolites, including amino acids, alkaloids, organic and fatty acids, nucleotides, vitamins, organosulfur compounds, and flavonoids. The pigment and polyphenol components have been separated and quantified by a targeted chromatographic high-performance liquid chromatography-photodiode array detector (HPLC-PDA) and CIEL*a*b* colorimetric assay, showing characteristic yellow and red components in each extract, related to a different milieu of anthocyanins and flavonoids as assigned by high-resolution mass spectrometry (MS).

Production of bio-fuel from plant oil asphalt via pyrolysis

In order to treat waste during oleic acid production, pyrolysis method was used to investigate the plant oil asphalt (POA) to obtain bio-fuel. It was found that the compounds contained alkane, alkene, fatty acid, plant sterol derivatives, alcohol and etc. in pyrolysis products of POA by Pyrolysis-Gas Chromatography-Mass Spectrometer (Py-GC-MS). The Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (ESI FT-ICR-MS) results showed that dehydrogenation and polymerization reactions took place during the pyrolysis process, but the main reaction was decarboxylation. According to van Krevelen diagram the nature of the bio-fuel can be evaluated. The acid value and viscosity of the resulting bio-fuel produced were higher than that of diesel fuel and reference bio-fuel. The calorific value showed a slight lower value than that of diesel oil. These studies nominated POA as a potential renewable feedstock for bio-fuel production the simple pyrolysis method.