Gas Chromatography-mass Spectrometry Techniques Research Articles

THE USE OF GC-MS AND FTIR SPECTROSCOPY COUPLED WITH MULTIVARIATE ANALYSIS FOR THE DETECTION OF RED GINGER OIL ADULTERATION

The ginger oil traded worldwide could come from various sources. Standard quality is the most critical aspect of ensuring customer safety. This study aims to develop an analytical method for red ginger oil (RGO) authentication. Chemical compositions of red ginger oil were determined by Gas Chromatography-Mass Spectrometry (GC-MS). The Fourier Transform Infrared Spectroscopy (FTIR) coupled with multivariate analysis (discriminant analysis (DA), partial least square (PLS), and principal component regression (PCR) were used to identify and quantify the adulterant. The total terpenoid compounds were 55.72%, with the percentage of monoterpenes at 34.29% and sesquiterpenes at 21.43%. E-Citral (19.01%), Z-Citral (14.82%), Geranyl Acetate (11.90%), Geraniol (9.56%), 1,8-Cineole (5.84%), and camphene (4.92%) were identified as the main constituents. The best PLS model for quantifying the level of palm oil in RGO was at the wavenumber 3100–2700 cm–1, while the region of 3100 – 2700 and 1850 – 650 cm–1 was suitable for detection of soybean adulterants. FTIR spectroscopy coupled with chemometrics produced accurate and fast authentication of red ginger oil without the used solvent. Then, the GC-MS technique could identify the chemical constituents present in the red ginger oil.

Gas Chromatography-Mass Spectrometry Analysis and Antihyperglycemic Property of Lindernia crustacea (L.) F. Muell.

Lindernia crustacea (L.) F. Muell is a small herbaceous plant with several ethnomedicinal values. The present study investigated the phytochemical content and alpha-amylase and alpha-glucosidase inhibitory property of Lindernia crustacea. Methanolic crude extract of plant was obtained following the Soxhlet method. The crude extract was studied for alpha-amylase and alpha-glucosidase inhibitory activity. Phytochemical analysis was carried out using the gas chromatography-mass spectrometry technique. Furthermore, docking study was carried out with the phytocompounds to see the binding affinity with the enzymes. In silico drug-likeness and pharmacological properties were also carried out using Swiss absorption, distribution, metabolism and excretion, and absorption, distribution, metabolism, excretion and toxicity lab tools. The plant extracts showed concentration-dependent inhibition of enzyme activities with half-maximal inhibitory concentration values of 3.11 mg/ml and 548.9 μg/ml for alpha-amylase and alphaglucosidase, respectively. Gas chromatography-mass spectrometry study identified ten phytocompounds with molecular weights ranging from 264.4 to 561 g/mol. Docking study showed 1-(4-Hydroxybenzoyl)- 6,7-dimethoxyisoquinoline as the best binding compound with the enzymes. Phytocompounds identified from Lindernia crustacea were predicted to have substantial drug-likeness and absorption, distribution, metabolism, excretion and toxicity properties. The enzyme inhibition study and binding interactions of phytocompounds suggest promising alpha-amylase and alpha-glucosidase inhibitory activity of Lindernia crustacea. Therefore, the aerial part of Lindernia crustacea may be further investigated to know the exact mode of biological actions.

Reversed-Phase High-Performance Liquid Chromatography Quantification, Gas Chromatography-Mass Spectrometry Study and In Vitro Antioxidant Potential of Clerodendrum serratum Linn. Roots

The present study was aimed to identify and to quantify the phytoconstituents by gas chromatography-mass spectrometry, reversed-phase high-performance liquid chromatography techniques and further to evaluate their in vitro antioxidant potential. In this study, the roots of Clerodendrum serratum Linn. was subjected to soxhlet extraction using n-hexane, chloroform, ethyl acetate and ethanol solvents and the obtained extracts (CSRH, CSRC, CSREA and CSRA) were analyzed by gas chromatography-mass spectrometry technique. The caffeic acid and beta-sitosterol were quantified from the extracts using reversed-phase high-performance liquid chromatography technique. Total phenolic and flavonoid content were determined using established methods viz. Folin-Ciocalteu and aluminium chloride colorimetric assay. Antioxidant potential was assessed using in vitro methods such as 2,2-diphenyl-1-picrylhydrazyl scavenging activity; ferric reducing ability of plasma assay and total antioxidant activity. The gas chromatography-mass spectrometry analysis revealed the presence of 48 compounds, out of which 41 compounds were identified and among them caffeic acid and beta-sitosterol were quantified using reversed-phase high-performance liquid chromatography technique. The abundance of phenolic and flavonoid content was found in CSREA and CSRA fractions. The half maximal inhibitory concentration values of 2,2-diphenyl-1-picrylhydrazyl assay was found to be 1.24, 3.36, 10.61 μg/ml for the CSRA, CSREA and CSRC fractions respectively and the total antioxidant activity was found to be 960±0.25, 766±0.14 and 816.6±0.28 μg/mg for the CSRC, CSREA and CSRA fractions respectively showing strong antioxidant activity. The ferric reducing ability of plasma assay showed strongest reducing power for CSRA and CSREA fractions. The results showed that the CSRA and CSREA fractions had strong antioxidant potential. It may be concluded from the results that the Clerodendrum serratum Linn. roots possesses significant antioxidant potential may be due to presence of potent phenolic and flavonoid compounds and these finding supports the traditional use of plant to treat the oxidative stress and related disorders.

Using targeted metabolomics to elucidate the indole auxin network in plants.

The plant hormone auxin plays important roles throughout the entire life span of a plant and facilitates its adaptation to a changing environment. Multiple metabolic pathways intersect to control the levels and flux through indole-3-acetic acid (IAA), the primary auxin in most plant species. Measurement of changes in these pathways represents an important objective to understanding core aspects of auxin signal regulation. Such studies have become approachable through the technologies encompassed by targeted metabolomics. By monitoring incorporation of stable isotopes from labeled precursors into proposed intermediates, it is possible to trace pathway utilization and characterize new biosynthetic routes to auxin. Chemical inhibitors that target specific steps or entire pathways related to auxin synthesis aid these techniques. Here we describe methods for obtaining stable isotope labeled pathway intermediates necessary for pathway analysis and quantification of compounds. We describe how to use isotope dilution with methods employing either gas chromatography or high performance liquid chromatography mass spectrometry techniques for sensitive analysis of IAA. Complete biosynthetic pathway analysis in seedlings using multiple stable isotope-labeled precursors and chemical inhibitors coupled with highly sensitive liquid chromatography-mass spectrometry methods are described that allow rapid measurement of isotopic flux into biochemical pools. These methods should prove to be useful to researchers studying aspects of the auxin metabolic network in vivo in a variety of plant tissues and during various environmental conditions.

INFLUENCE OF EXTRACTION METHODS ON THE COMPOSITION OF VARIOUS FATTY ACIDS IN SHEA BUTTER PROCESSED FROM SELECTED SHEA KERNELS

The functional groups and the constituent composition of Shea butter (a mixture of stearic, oleic, linoleic, palmitic and arachidic fatty acids along with bioactive components) are greatly influenced by the climatic conditions of the Shea tree, the processing conditions of the Shea kernel, and the extraction methods of Shea butter. Also, the choice and application of Shea butter (Pharmaceuticals, Cosmetics, Chocolates) are greatly influenced by the composition and functional groups present in butter. In this research, optimally processed Shea kernel (4.3-day Shea fruit picking period, 120 minutes Shea nut boiling duration, 86 oC drying temperature) and locally processed Shea kernel were subjected to a potpourri of Shea butter extraction methods to investigate their influence on the variations of the constituent fatty acids. Fourier Transformation infrared spectroscopy (FTIR) and Gas Chromatography-Mass Spectroscopy (GC-MS) techniques were used to establish the functional groups and the mass composition of the constituent fatty acids. The results show that for all samples, stearic and oleic acids predominate jointly, constituting a minimum of 84%. Also, samples contained alkane, alkene, carbonyl, and ester functional groups. Shea butter obtained from optimally processed Shea kernel and optimum traditional extraction method gave 45.9% and 39.2% mass composition of Stearic and Oleic acid, respectively, and traces of the other acids and the balance bio-actives. Results for other Shea kernel treatment and butter extraction methods are also reported.

Virucidal Activity of Essential Oils From Citrus x aurantium L. Against Influenza A Virus H1N1:Limonene as a Potential Household Disinfectant Against Virus

This work explored the compositions of a crude extract of peels of Citrus x aurantium using a gas chromatography-mass spectrometry (GC-MS) technique. The crude extract of peels of C. × aurantium was analyzed by GC-MS revealing the presence of limonene as the major compound, accounting for 93.7% of the total. Virucidal activity of the oil of C. x aurantium peels against influenza A virus H1N1 was evaluated by the ASTM E1053-20 method. Moreover, the virucidal activity was also investigated of D-limonene, the major terpene in essential oils of C. x aurantium, and its enantiomer L-limonene. The essential oil of the C. x aurantium peels produced a log reduction of 1.9 to 2.0, accounting for 99% reduction of the virus, while D- and L-limonene exhibited virucidal activity with a log reduction of 3.70 to 4.32 at concentrations of 125 and 250.0 µg/mL, thus reducing the virus by 99.99%. Previous work found that D-limonene exhibited antiviral activity against herpes simplex virus, but L-limonene, an enantiomer of D-limonene, has never been reported for antiviral activity. This work demonstrates the antiviral activity of L-limonene for the first time. Moreover, this work suggests that concentrations of 0.0125% to 0.025% of either D- or L-limonene can possibly be used as a disinfectant against viruses, probably in the form of essential oil sprays, which may be useful disinfectants against the airborne transmission of viruses, such as influenza and COVID-19.

PAH EXPOSITION AND CARCINOGENICITY RISK EVALUATION IN SOILS FROM NIGER DELTA, NIGERIA

Environmental pollution has become a cross-cutting issue in recent decades, garnering the attention of governments, governmental agencies, the general public, and scientific communities, and (PAHs) is one of the biggest hazards to public health. PAHs were evaluated in Niger Delta soils using a gas chromatography-mass spectrometry (GC-MS) technique to assess their distribution, exposure, and carcinogenicity risk. The SS1 location in the city had the highest amounts of PAH. The toxic equivalency factor (TEF), incremental lifetime cancer risk (ILCRs) and as well as a global comparison analysis was employed. The results showed that three city sample locations surpassed the clean-up standards for BaP, 0.1 mg/kg, according to the data. Carcinogenic polycyclic aromatic hydrocarbons (PAHs) are those polycyclic aromatic hydrocarbons (PAHs) determined as Group A (known human) and Group B (probable) carcinogens and currently seven PAHs classified probable human carcinogens (Group B2). The majority of the risk associated with PAHs is attributed to benzo (a) pyrene and a few other PAHs. The results further revealed that six out of the seven HMW PAHs are known human carcinogens. The results of this study were found to be within permissible levels recommended. However, the authors strongly advocate a remediation alternative aiming at decontaminating the PAH-polluted soils at SS1, SS3, and SS2.

Characterization of volatile compounds nongrafted and pumpkin-grafted bitter gourd(Momordica charantia L.)

Bitter melon (Momordica charantia L.) is a unique vegetable-fruit possessing several multifarious health benefits. In this study, the plant extraction obtained from grafted bitter gourd onto pumpkin (Cucurbita maxima) and nongrafted bitter gourd cultivated under greenhouse conditions were evaluated for their constituents of volatile compounds. Gas chromatography-mass spectrometry (SPMEGC-MS) techniques were employed to determine these compounds in the leaves (young, middle, and old-age) and fruits (unripe and ripe) of bitter gourd. The volatile compounds in the leaves of pumpkin during the three stages mentioned above were also investigated. Overall, 72 in leaves and 56 in fruits of bitter gourd compounds belonging to eight major chemical groups were identified: acid, alcohol, aldehyde, alkane, ester, ketone, lactone, and terpene. A total of 52 compounds belonging to the eight major groups mentioned above were also identified from pumpkin leaves. Aldehyde, terpene, and ester were reactively the most prevalent groups found in bitter gourd and pumpkin. The grafted bitter gourds developed up to 23 new compounds in leaves and 15 in their fruits. The grafting of bitter gourd onto pumpkin also halted the production of up to 15 different compounds in fruits and seven in their leaves. Based on principal component analysis and cluster analysis results, the dissimilarity between grafted and nongrafted bitter gourd decreased over time from young to old leaves or unripped to ripe fruit. In conclusion, the grafting of bitter gourd onto pumpkin drastically reshaped the composition of volatile compounds in both leaves and fruits of bitter gourd.

ANALYTICAL METHOD DEVELOPMENT AND VALIDATION OF GENOTOXIC IMPURITY p-ANISALDEHYDE IN TENELIGLIPTIN USING GC-MS

This research aimed to develop a sensitive GC–MS (Gas Chromatography-Mass Spectrometry) technique for the estimation of genotoxic impurity p-anisaldehyde in Teneligliptin drug to meet the current regulatory requirements. A simple and specific method was developed and validated according to ICH (International Council for Harmonization) guidelines. The LOQ (limit of quantitation) and LOD (limit of detection) values were determined as 0.38 and 0.12 ppm, respectively. The approach was linear in the range of 0.38–56 ppm with a correlation coefficient of 0.9997. The average recovery of Teneligliptin was 93%. The validation parameters strongly support that the developed technique is suitable to determine the p-anisaldehyde in Teneligliptin hydrobromide hydrate.

Host seed type and volatile compound abundance level mould host location and preference behaviours in Callosobruchus maculatus (Fabricius, 1775) (Coleoptera: Chrysomelidae)

Dry seeds of cowpea, an important food, and cash crop to farmers, are heavily infested by Callosobruchus maculatus (Fabricius, 1775) during storage, causing huge economic loss. As a result, farmers spray pesticides on their harvest to control the pest attack with little consideration for the consequences of their actions. Due to health and environmental concerns associated with pesticide applications, farmers, marketers, and end-users are seeking alternative safer routes to handling this infestation problem. Thus, this study investigated the response of mated female C. maculatus to odour cues from different bean types using two-arm and four-arm olfactometers. The volatile organic compounds from the preferred beans (Borno brown and black-eyed beans-cultivars of Vigna unguiculata Walper, 1843 and adzuki bean – Vigna angularis (Willdenow) Ohwi & Ohashi, 1969), were analysed using gas chromatography-mass spectrometry (GCMS) techniques and headspace volatile organic compounds were tested in 2-arm olfactometer with the view to identifying possible attractants or deterrents that could be used in effective control of storage pest. The results indicated that (a) the female C. maculatus responded discriminatorily to odour stimuli from the bean types tested, (b) eighteen volatile compounds were present in the bean types tested and (c) the volatile compounds identified varied in abundance profile. These suggest that host location and selection behaviours by female C. maculatus are moulded by the types and concentrations of the volatile compounds present in the beans.

Liquid Chromatography-Electron Capture Negative Ionization-Tandem Mass Spectrometry Detection of Pesticides in a Commercial Formulation.

Negative chemical ionization (NCI) and electron-capture negative ionization (ECNI) are gas chromatography–mass spectrometry (GC–MS) techniques that generate negative ions in the gas phase for compounds containing electronegative atoms or functional groups. In ECNI, gas-phase thermal electrons can be transferred to electrophilic substances to produce M–• ions and scarce fragmentation. As a result of the electrophilicity requirements, ECNI is characterized by high-specificity and low background noise, generally lower than EI, offering lower detection limits. The aim of this work is to explore the possibility of extending typical advantages of ECNI to liquid chromatography–mass spectrometry (LC–MS). The LC is combined with the novel liquid-EI (LEI) LC–EIMS interface, the eluent is vaporized and transferred inside a CI source, where it is mixed with methane as a buffer gas. As proof of concept, dicamba and tefluthrin, agrochemicals with herbicidal and insecticidal activity, respectively, were chosen as model compounds and detected together in a commercial formulation. The pesticides have different chemical properties, but both are suitable analytes for ECNI due to the presence of electronegative atoms in the molecules. The influence of the mobile phase and other LC- and MS-operative parameters were methodically evaluated. Part-per-trillion (ppt) detection limits were obtained. Ion abundances were found to be stable with quantitative linear detection, reliable, and reproducible, with no influence from coeluting interfering compounds from the sample matrix.

LABORATORY EVALUATION OF THE ROOT EXUDATES OF THE CLERODENDRON INERME IN CONTROLLING ON APHIS CRACCIVORA KOCH.

ABSTRACT This study was conducted to check for the biological efficacy of root exudates of Clerodendron inerme on some biological aspects of Aphis craccivora. Also, the study included the detection of the compounds in root exudates of C. inerme by using the gas chromatography-mass spectrometry technique. Results showed that the high concentration of root exudates recorded high cumulative mortality of the adult insects after exposure time 1, 2, and 3 days from treatments 28.5, 33.8, and 40.3% respectively compared with 32.4, 39.3 and 48.5% respectively of nymphs insects. The developmental period of the immature stages has increased from 6.5days in the control treatment compared with 9.3 days at high concentration while the fecundity of adult females reduced to reach 18.00 nymph at high concentration compared with 26.66 nymphs in the control treatment. GC-MS analysis of root exudates of C. inerme showed the presence of many compounds such as2-Propenoic acid, ethenyl ester, 2-Phenanthrenol. Keywords: Aphis craccivora, Clerodendron inerme, GC-MS Analysis

An experimental and kinetic modeling study of benzene pyrolysis with C2−C3 unsaturated hydrocarbons

A combined experimental and kinetic modeling study is carried out to explore the influences of added acetylene, ethylene, propylene, and propyne on the reaction schemes of benzene pyrolysis. Pyrolysis of benzene with and without the presence of the C2- or C3- unsaturated hydrocarbons (HCs) is conducted in a single pulse shock tube coupled to gas chromatography-mass spectrometry technique. A minimum of 30 species is detected in each reaction system, and their mole fraction profiles are obtained over the temperature range 1030–1800 K at a nominal pressure of 20 bar and a nominal reaction time of 4 ms. With updates based on recent theoretical studies, our ongoing detailed kinetic model with 552 species and 4958 reactions can successfully reproduce the decomposition reactivity of the fuels, formation of decomposition products, and the growth of aromatics in the pyrolysis of different fuel mixtures. Various considerations apply to all studied binary mixtures. The addition of C2- and C3- HCs to the reaction system leads to C2H2 formation, and consequently promotes the HACA mechanism starting from phenyl radical (C6H5) at relatively low temperatures. The resulted phenylacetylene, formed through C6H5+C2H2 reaction, promotes the addition-elimination reaction C6H5C2H + C6H5 leading to the enhanced and early formation of all C14H10 PAH isomers including ethynyl biphenyl, methylene-fluorene, diphenylacetylene, phenanthrene, and anthracene. It is also noteworthy that the existence of C2H2 as fuel or its production from C2H4, C3H6, and C3H4-P decomposition results in numerous compounds with ethynyl branches such as ethynyl biphenyl, diethynyl naphthalene, and ethynyl acenaphthylene. Considering the specific features of the different fuel mixtures, the addition of acetylene intensifies the HACA route leading to greater acenaphthylene formation, while naphthalene formation remains similar to the pure benzene case due to the limited H-atoms. Differently, in benzene-C2H4 co-pyrolysis, naphthalene and acenaphthylene are mainly formed through reactions between PAH radicals (phenylacetylene radical and naphthyl radical, respectively) and ethylene. Concerning benzene-C3 co-pyrolysis, indene is the major C9 species resulting from the reaction of benzene/phenyl with C3 fuels. This is an important theoretical pathway to indene which is experimentally probed here for the first time. The high concentration of indene leads to the enhanced formation of naphthalene and acenaphthylene through the reactions of indenyl radical with methyl and propargyl (C3H3) radicals, respectively. Afterwards, the naphthyl radicals participate in the formation of several larger C11–13 PAHs such as methylnaphthalene, ethynylnaphthalene and fluorene through their reactions with CH3, C2H2 and C3H4-P/C3H3, respectively.

Determination of ethyl carbamate in wine by matrix modification-assisted headspace single-drop microextraction and gas chromatography–mass spectrometry technique

A novel method for the analysis of ethyl carbamate in wine has been developed by coupling matrix modification-assisted headspace single-drop microextraction and gas chromatography-mass spectrometry (GC–MS) techniques. The method was developed by optimizing the matrix modifier and extraction parameters. The calibration method was followed by quantifying the internal isotope standard. The results suggested that the method was linear in the concentration range of 2–1000 ng/mL (R2 = 0.9996). The method presents a detection limit of 1.5 ng/mL, and the quantification limit is 5 ng/mL. The accuracy ranged between 94.9 and 99.9%, and the precision of the method was less than 5%. The method was applied for the detection of wine samples, and the results exhibited no significant difference when compared to the solid phase extraction method.

Application of Artificial Neural Network Based on Traditional Detection and GC-MS in Prediction of Free Radicals in Thermal Oxidation of Vegetable Oil.

In this study, electron paramagnetic resonance (EPR) and gas chromatography-mass spectrometry (GC-MS) techniques were applied to reveal the variation of lipid free radicals and oxidized volatile products of four oils in the thermal process. The EPR results showed the signal intensities of linseed oil (LO) were the highest, followed by sunflower oil (SO), rapeseed oil (RO), and palm oil (PO). Moreover, the signal intensities of the four oils increased with heating time. GC-MS results showed that (E)-2-decenal, (E,E)-2,4-decadienal, and 2-undecenal were the main volatile compounds of oxidized oil. Besides, the oxidized PO and LO contained the highest and lowest contents of volatiles, respectively. According to the oil characteristics, an artificial neural network (ANN) intelligent evaluation model of free radicals was established. The coefficients of determination (R2) of ANN models were more than 0.97, and the difference between the true and predicted values was small, which indicated that oil profiles combined with chemometrics can accurately predict the free radical of thermal oxidized oil.

Chemical Profiles of Terminalia catappa LINN Nut and Terminalia subspathulata KING Fruit

Terminalia catappa and Terminalia subspathulata are two species of the Combretaceae family of medium to large forest trees. The fruits of T. catappa are known for the edible nuts commonly known as tropical almonds due to their similarity in taste with almonds of commerce. Therefore, the chemical profiles of the fruits of the two Terminalia species were examined to ascertain their potential value for food or health uses. Gas chromatography-mass spectrometry (GCMS) and ultrahigh-pressure liquid chromatography-electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS) techniques were employed to profile the extracts to ensure good coverage of the classes of metabolites of the fruit extracts. The GCMS results revealed that T. catappa nuts were rich in palmitic acid (33.2%), linoleoyl chloride (29.1%), and oxacyclohexadecan-2-one commonly known as pentadecanolide (16.2%). In comparison, the major constituents of T. subspathulata fruits were palmitic acid (18.1%) and its methyl ester, methyl palmitate (9.3%). Furthermore, a total of 38 compounds were putatively identified in the 70% aqueous methanolic extracts of both species via UHPLC-ESI-MS/MS analysis, comprising three organic acids, sixteen hydrolysable tannins, ten phenolic acids, eight flavonoids, and a diarylheptanoid. The GCMS- and liquid chromatography-mass spectrometry- (LCMS-) LCMS-based metabolite profiles obtained in the present study have revealed the diversity of chemical constituents in the T. catappa nuts and T. subspathulata fruits, potentially valorised as functional foods nutraceutical ingredients for plant-based health products.

Extraction and identification of the components of Thymbra spicata L. and Satureja khuzestanica Jamzad Oils native to Ilam province by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS)

Satureja khuzistanica Jamzad (Lamiaceae) and Thymbra spicata L. (Lamiaceae) are medicinal plants belonging to the genera of Satureja and Thymbra, having many uses in traditional Iranian medicine. S. khuzistanica is used to treat different diseases such as cramps, nausea, and infectious diseases. Medicinal plants, extracts and essential oils are of special importance for pharmacy, health and food industries. S. khuzistanica and T. spicata plants were collected from Dehloran located in south of Ilam province in western Iran. Then, they were dried and powdered. Headspace-solid phase microextraction (HS-SPME) and Gas Chromatography-mass Spectrometry (GC-MS) techniques were used to obtain extracts of mentioned plants and identify their active compounds. Essential oil from T. spicata contained 45 chemical compounds, whose main ones were isothymol (36.24%), gamma-terpinene (17.94%), O-cymene (10.92%), trans-caryophyllene (7.81%), alpha-pinene (7.24%), and camphene (3.61%). Also, essential oil from S. khuzestanica contained 43 chemical compounds which main ones were carvacrol (71.99%), camphene (2.84%), alpha-pinene (1.63%), 1,8-Cineole (1.51%). carvone (1.44%) and beta-pinene (1.42). Results from present study indicated that antioxidative and antimicrobial compounds such as carvacrol were found in both plants (S. khuzestanica and T. spicata) from the Laminaceae family. Therefore, essential oils of these plants can find applications as antioxidant, antimicrobial and antiseptic compounds for medicinal and health purposes.

A new approach in deep desulfurization of model fuel through integration of electrochemical oxidation and liquid-liquid extraction in a biphasic system

An extraction-electrooxidation (E-EODS) system is introduced for the removal of dibenzothiophene (DBT) from model fuel (DBT in n-hexane). The process is run in an electrochemical cell as a batch reactor, where, the model fuel is in contact with an appropriate immiscible polar solvent composed of acetonitrile and water (MeCN-water, 90:10% v/v) that serves as both the extraction solvent and electrochemical medium. The electrochemical oxidation of DBT, which is extracted into the MeCN-water phase, enhances the continuous removal of DBT from the model fuel phase. The effects of the composition of the extraction solvent, applied potential and the process time on DBT removal efficiency are assessed. The results indicate that with the selection of the MeCN-water, 90:10 v/v in a 1:1 ratio respect to the model fuel, this extraction method yields about 100% extraction efficiency within 5 h, at 25 °C at 2.9 V and atmospheric pressure as determined by HPLC technique. Cyclic voltammetry (CV), Fourier transform infrared (FT-IR) spectroscopy, and gas chromatography-mass spectrometry (GC–MS) techniques are applied to identify the electrochemical oxidation products of DBT. The electrochemical oxidation-derived extraction process through this method is innovative and feasible for deep desulfurization of liquid fossil fuels.

Targeted and Nontargeted Detection and Characterization of Trace Organic Chemicals in Human Serum and Plasma Using QuEChERS Extraction.

Humans are exposed to a broad range of organic chemicals. Although targeted gas chromatography mass spectrometry techniques are used to quantify a limited number of persistent organic pollutants and trace organic contaminants in biological samples, nontargeted, high-resolution mass spectrometry (HRMS) methods assess the human exposome more extensively. We present a QuEChERS extraction for targeted and nontargeted analysis of trace organic contaminants using HRMS and compare this method to a traditional, cartridge-based solid-phase extraction (SPE). Following validation using reference and spiked serum samples, the method was applied to plasma samples (n = 75) from the Prospective investigation of Obesity, Energy, and Metabolism (POEM) study. We quantified 44 analytes using targeted analysis and 6247 peaks were detected using the nontargeted approach. Over 90% of targeted analytes were at least 90% recovered using the QuEChERS method in spiked serum samples. In nontargeted analysis, 84% of the peaks were above the method detection limit with area counts up to 3.0 × 105 times greater using the QuEChERS method. Of the targeted compounds, 88% were also identified in the nontargeted analysis. We categorized the 4212 chemicals assigned an identity in using EPA's CompTox Dashboard and 1076 chemicals were found in at least one list. The category with the highest number of chemicals was "androgen or estrogen receptor activity." The findings demonstrate that a QuEChERS technique is suitable for both targeted and nontargeted analysis of trace organic contaminants in biological samples.

Assessment of lipid profile in fat body and eggs of Rhipicephalus microplus engorged females exposed to (E)-cinnamaldehyde and α-bisabolol, potential acaricide compounds

In the present study, the lipid profile from the fat body and eggs of Rhipicephalus microplus was evaluated after exposure of engorged females to (E)-cinnamaldehyde and α-bisabolol, substances which have acaricide potential according to the literature. Engorged females collected from artificially infested cattle were immersed in a concentration of 10.0 mg/mL of each substance. Dissection of the female fat bodies was performed at different times (72 h and 120 h), for subsequent lipid extraction. In addition, on the fifth day of oviposition, were collected 50.0 ml50.0 mL aliquots of the egg mass of each treatment to perform the same lipid extraction procedure. To assess the lipid profiles, the samples were submitted to the thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GCMS) analysis. Furthermore, an in silico analysis was performed using PASS online® software to predict the possible molecular targets of (E)-cinnamaldehyde and α-bisabolol. As result, the main lipids identified from the fat body were triacylglycerides, fatty acids, and cholesterol, whereas, triacylglycerides (TAG), fatty acids (FA), and cholesterol (CHO) and cholesterol esters (CHOE), were identified in the eggs. The results also showed a significant increase (p < 0.05) of CHO in the fat body in the group exposed to (E)-cinnamaldehyde at 72 h (0.12 μg/fat body) and 120 h (0.46 μg/fat body), in the eggs from females treated with this same substance, there was a significant reduction (p < 0.05) in the amount of CHO (0.21 μg), compared to the water control group (0.45 μg). In the GCMS technique, 5 chemical classes were found, and variations were observed between these substances, mainly hydrocarbons and steroids, in the different groups, and (E)-cinnamaldehyde promoted the greatest changes. From the predictions of the in silico study, 38 and 20 targets were selected, respectively, which are mainly related to alterations in lipid metabolism, immune system and nervous system. This study provides the first report of changes in lipid metabolism of R. microplus exposed to (E)-cinnamaldehyde and α-bisabolol, as well as presenting possible activity on the molecular targets of these substances, expanding knowledge for the potential use of these compounds in the development of botanical acaricides.