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Formic and acetic acids are the most abundant gaseous organic acids and play the key role in the atmospheric chemistry. In iodine-adduct chemical ionization mass spectrometry (CIMS), the low utilization efficiency of methyl iodide and humidity interference are two major issues of the vacuum ultraviolet (VUV) lamp initiated CIMS for on-line gaseous formic and acetic acids analysis. In this work, we present a new CIMS based on VUV lamp, and the ion-molecular reactor is separated into photoionization and chemical ionization zones by a reducer electrode. Acetone was added to the photoionization zone, and the VUV photoionization acetone provided low-energy electrons for methyl iodide to generate I - , and the addition of acetone reduced the amount of methyl iodide by 2/3. In the chemical ionization zone, a headspace vial containing ultrapure water was added for humidity calibration, and the vial changes the sensitivity as a function of humidity from ambiguity to well linear correlation (R 2 > 0.95). With humidity calibration, the CIMS can quantitatively measure formic and acetic acids in the humidity range of 0%-88% RH. In this mode, limits of detection of 10 and 50 pptv are obtained for formic and acetic acids, respectively. And the relative standard deviation (RSD) of quantitation stability for 6 days were less than 10.5%. This CIMS was successfully used to determine the formic and acetic acids in the underground parking and ambient environment of the Shandong University campus (Qingdao, China). In addition, we developed a simple model based formic acid concentration to assess vehicular emissions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

In this study, phenolic compounds using deep eutectic solvents (DES) were extracted from cork dust, and the biogas production potential of DES-treated cork dust samples was determined. The DES treatment was carried out using choline chloride and formic acid (1:2 M ratio) at various temperatures (90, 110 and 130 °C) and treatment times (20, 40 and 60 min) at a solid-to-solvent ratio of 1:10 g mL -1 . The highest total phenolic content (137 mg gallic acid equivalent (GAE) g -1 dry cork dust) was achieved at 110 °C/20 min. The extracts exhibited an antioxidant capacity of up to 56.3 ± 3.1 % 1,1-diphenyl-2-picrylhydazyl (DPPH) inhibition at a dilution rate of 100. DES treatment resulted in minimal sugar solubilization at low temperatures, while approximately 42 % of the xylan fraction in the biomass degraded under severe conditions (e.g., 130 °C/60 min). Catechin, 4-hydroxybenzoic acid and gallic acid were the major phenolics in DES extracts. The biogas yield of DES-treated cork dust increased with treatment severity. The highest biogas yield (115.1mL N g VS -1 ) was observed at 130 °C/60 min, representing an increase of 125 % compared to the untreated sample. SEM images revealed that the surface structure of the samples became smoother after mild pretreatment and rougher after harsh pretreatment. Compositional and FTIR analyses indicated that a higher biogas formation potential was associated with increased cellulose content in the substrate, which could be attributed to hemicellulose solubilization in the hydrolysate. Overall, DES pretreatment effectively enhanced phenol extraction and anaerobic degradability., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In order to obtain the best mass spectrometry identification results for using the most appropriate methods in clinical practice, we explore the optimal pretreatment methods for different species and morphologies of filamentous fungi. 98 fungal strains were treated with formic acid sandwich method, dispersion method, extraction method, and other methods using a medium element mass spectrometer (EXS3000) as a platform. Each strain had three targets, and the identification rates and confidence differences under different pre-treatment methods were compared to evaluate the identification effects of these methods. The mass spectrometry identification rates of 98 filamentous fungi obtained after pre-treatment with formic acid sandwich method, dispersion method, and extraction method were 85.71%, 82.65%, and 75.51%, respectively. The identification rate of the formic acid sandwich method was significantly higher than the other two methods (P < 0 005) has the best identification ability and the obtained confidence is also higher than the other two methods. The use of formic acid sandwich method for mass spectrometry identification of filamentous fungi can achieve ideal identification results, which is suitable for mass spectrometry identification of filamentous fungi in conventional laboratories., (© 2024. The Author(s).)

Methanol poisoning is caused by the toxicity of formate, a by-product of methanol metabolism. Measurement of blood formate concentrations is required for emergency treatment and investigation of the cause of death. In this study, we measured concentrations of formate in the plasma of a patient with methanol poisoning using headspace gas chromatography--mass spectrometry (HS-GC--MS) and a formate assay kit. Results showed a discrepancy as the quantitative values of the kit were higher than those of HS-GC--MS. Metabolic profiling of low-molecular-weight organic compounds in patient plasma samples showed that the concentrations of lactate were correlated with the values obtained using the kit. We observed a progression when lactate and lactate dehydrogenase were added to the kit reaction simultaneously, even in the absence of formate. Moreover, disulfiram, an aldehyde dehydrogenase inhibitor, suppressed the values of patient plasma samples in the formate assay kit, implying that formate production from remaining methanol in patient plasma samples via formaldehyde occurred during the kit reaction. The reactions of the kit with lactate and methanol were undesirable for accurate measurement of formate concentration in the sample. However, considering that elevated concentrations of lactate and remaining methanol both cause acidosis and are dangerous to the body, cross-reactions with lactate and methanol in the formate assay kit may be acceptable for rapid diagnosis in facilities where HS-GC--MS and other physical and chemical equipment are unavailable., (© The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Abstract: Many deaths caused by methanol occur as a result of intentional suicide attempts or accidental ingestion, and several investigators have quantified methanol and formic acid in blood and organs. However, to the best of our knowledge, no reports have described regional differences in the concentration of methanol in the brain. A man in his 50s drank alcohol that had been deliberately contaminated with methanol by his wife, and he died of multiple-organ failure after 4 days of intensive medical treatment including hemodialysis. On medicolegal autopsy, cross sections of the brain showed scattered petechial hemorrhage in the brain stem and microscopic hemorrhage with congestion in the bilateral putamina, which showed pinkish discoloration. The concentrations of methanol, formic acid, and ethanol in autopsy samples were measured by headspace gas chromatography, revealing relatively high concentrations of residual methanol and formic acid in the brain (especially in the basal ganglia), although methanol had been eliminated from the blood. Even after 4 days of medical treatment, postmortem toxicological analysis of the brain tissue indicated methanol ingestion. The accumulation of formic acid and the consequent local metabolic acidosis may cause brain lesions., Competing Interests: The authors report no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Currently, the QuEChERS method represents the most widely used sample preparation protocol worldwide for analyzing pesticide residues in a broad variety of matrices both in official and non-official laboratories. The QuEChERS method using ammonium formate has previously proven to be advantageous compared to the original and the two official versions. On the one hand, the simple addition of 0.5 g of ammonium formate per gram of sample is sufficient to induce phase separation and achieve good analytical performance. On the other hand, ammonium formate reduces the need for maintenance in routine analyses. Here, a modified QuEChERS method using ammonium formate was applied for the simultaneous analysis of organochlorine pesticide (OCP) residues in agricultural soil. Specifically, 10 g of the sample was hydrated with 10 mL of water and then extracted with 10 mL of acetonitrile. Next, phase separation was carried out using 5 g of ammonium formate. After centrifugation, the supernatant was subjected to a dispersive solid-phase extraction clean-up step with anhydrous magnesium sulfate, primary-secondary amine, and octadecylsilane. Gas chromatography-mass spectrometry was used as the analytical technique. The QuEChERS method using ammonium formate is demonstrated as a successful alternative for extracting OCP residues from a soil sample.

Analytical methods for the quantification of the new 8-aminoquinoline antimalarial tafenoquine (TQ) in human blood, plasma and urine, and the 5,6-orthoquinone tafenoquine metabolite (5,6-OQTQ) in human plasma and urine have been validated. The procedure involved acetonitrile extraction of samples followed by ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Chromatography was performed using a Waters Atlantis T3 column with a gradient of 0.1% formic acid and acetonitrile at a flow rate of 0.5 mL per minute for blood and plasma. Urine analysis was the same but with methanol containing 0.1% formic acid replacing acetonitrile mobile phase. The calibration range for TQ and 5,6-OQTQ in plasma was 1 to 1200 ng/mL, and in urine was 10 to 1000 ng/mL. Blood calibration range for TQ was 1 to 1200 ng/mL. Blood could not be validated for 5,6-OQTQ due to significant signal suppression. The inter-assay precision (coefficient of variation %) was 9.9% for TQ at 1 ng/mL in blood ( n = 14) and 8.2% for TQ and 7.1% for 5,6-OQTQ at 1 ng/mL in plasma ( n = 14). For urine, the inter-assay precision was 8.2% for TQ and 6.4% for 5,6-OQTQ at 10 ng/mL ( n = 14). TQ and 5,6-OQTQ are stable in blood, plasma and urine for at least three months at both -80 °C and -20 °C. Once validated, the analytical methods were applied to samples collected from healthy volunteers who were experimentally infected with Plasmodium falciparum to evaluate the blood stage antimalarial activity of TQ and to determine the therapeutic dose estimates for TQ, the full details of which will be published elsewhere. In this study, the measurement of TQ and 5,6-OQTQ concentrations in samples from one of the four cohorts of participants is reported. Interestingly, TQ urine concentrations were proportional to parasite recrudescence times post dosing To our knowledge, this is the first description of a fully validated method for the measurement of TQ and 5,6-OQTQ quantification in urine.

Background: Good quality colostrum is characterized by high immunoglobulin concentration and low pathogen load. Some methods of pathogen reduction can decrease immunoglobulin concentration and potentially affect their function. Objectives were to determine the effect of formic acid treatment on colostral bacterial and immunoglobulin (IgG) levels before feeding, and serum immunoglobulin concentration and neutralizing capabilities after feeding. Fifteen female Holstein calf pairs born < 12 h apart from different dams were randomly assigned to receive four liters of either untreated pooled (both dams) colostrum (MC) or colostrum acidified to pH 4.0-4.5 (AC). Colostrum characteristics estimated; pH, bacterial load, IgG concentration, and neutralization of Infectious Bovine Rhinotracheitis (IBRV/BoHV-1), Bovine Viral Diarrhea (BVDV) Types 1 and 2. Blood samples were collected on days 1, 3 and monthly for 6 months and were analyzed for IgG, and both viral plus leptospiral neutralization, and total protein (day 3 only)., Results: Compared to MC (mean 6.7, SD 0.4; median 6.8, range 6.0-7.3), AC pH was significantly reduced (mean 4.3, SD 0.2; median 4.3, range 4.0-4.5; P < 0.001). Total coliform count (cfu/mL) was also reduced (MC mean 149, SD 444; median 1, range 0-1,700; AC mean 8, SD 31; median 0, range 0-120; P = 0.02). Colostrum IgG concentration was not significantly different between MC (mean 93.3, SD 39.7; median 92.8, range 36.7-164.4 g/L) and AC (mean 101.9, SD 36.7; median 108.3, range 33.8-164.4 g/L; P = 0.54). In calves, serum IgG peaked on day 3 (MC mean 26.1, SD 34.9; median 169.2, range 8.3-151.0 g/L; AC mean 30.2, SD 48.7; median 188.8, range 3.1-204.4 g/L; P = 0.77), and apparent efficiency of IgG absorption was not different between groups (MC mean 24.3, SD 11.4, median 25.3, range 8.6-51.3%; AC mean 22.6, SD 21.7, median 21.6, range 4.1-58.9%; P = 0.65). Thereafter, IgG levels declined but did not differ between groups. MC and AC serum neutralizing titers for IBRV, BVDV Types 1 and 2, or Leptospira interrogans serovars Canicola, and Pomona and L. borgpetersenii serovar Hardjo were not different., Conclusions: Colostrum acidification significantly decreased bacterial load fed to newborn calves without affecting colostral IgG concentration or virus neutralization. In addition, acid treatment did not affect serum IgG concentration in calves or its activity against common pathogens., (© 2022. The Author(s).)

The following paper presents the method of determination of the percolation threshold in cement composites with expanded graphite by impedance spectroscopy. Most of the applications of cement composites with conductive additives require exceeding the percolation threshold. The ionic conductivity of cement matrix below the percolation threshold has a major impact on the conductivity of the composite, as a result, it significantly hinders the exploitation of these composites. The electric properties of cement composites with expanded graphite were evaluated by DC measurements and impedance spectroscopy (IS). Based on Nyquist plots, two equivalent circuits were adopted for the composites. Next, the values of capacitance and inductance of cement composites with expanded graphite were calculated from the fitted equivalent circuits. The analysis of the results shows that the percolation threshold occurs when the reactance of the composite changes from captative to inductive. Comparison between the values of percolation threshold obtained from DC measurements and IS shows that the method is effective for cement composites with conductive additives., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Oral diseases (e.g., dental caries, periodontitis) are developed when the healthy oral microbiome is imbalanced allowing the increase of pathobiont strains. Common practice to prevent or treat such diseases is the use of antiseptics, like chlorhexidine. However, the impact of these antiseptics on the composition and metabolic activity of the oral microbiome is poorly addressed. Using two types of oral biofilms-a 14-species community (more controllable) and human tongue microbiota (more representative)-the impact of short-term chlorhexidine exposure was explored in-depth. In both models, oral biofilms treated with chlorhexidine exhibited a pattern of inactivation (>3 log units) and fast regrowth to the initial bacterial concentrations. Moreover, the chlorhexidine treatment induced profound shifts in microbiota composition and metabolic activity. In some cases, disease associated traits were increased (such as higher abundance of pathobiont strains or shift in high lactate production). Our results highlight the need for alternative treatments that selectively target the disease-associated bacteria in the biofilm without targeting the commensal microorganisms.

Exposure to environmental and occupational particulate matter (PM) induces health effects on the cardio-pulmonary system. In addition, associations between exposure to PM and metabolic syndromes like diabetes mellitus or obesity are now emerging in the literature. Collection of exhaled breath condensate (EBC) is an appealing non-invasive technique to sample pulmonary fluids. This hypothesis-generating study aims to (1) validate an ion chromatography method allowing the robust determination of different metabolism-related molecules (lactate, formate, acetate, propionate, butyrate, pyruvate, nitrite, nitrate) in EBC; (2) apply this method to EBC samples collected from workers exposed to quartz (a known inflammatory particle), to soapstone (a less inflammatory particle than quartz), as well as to controls. A multi-compound standard solution was used to determine the linearity range, detection limit, repeatability and bias from spiked EBC. The biological samples were injected without further treatment into an ion chromatograph with a conductivity detector. RTube ® were used for field collection of EBC from 11 controls, 55 workers exposed to soapstone and 12 volunteers exposed to quartz dust. The analytical method used proved to be adequate for quantifying eight anions in EBC samples. Its sub-micromolar detection limits and repeatability, combined with a very simple sample preparation, allowed an easy and fast quantification of different glycolysis or nitrosative stress metabolites. Using multivariate discriminant analysis to maximize differences between groups, we observed a different pattern of anions with a higher formate/acetate ratio in the EBC samples for quartz exposed workers compared to the two other groups. We hypothesize that a modification of the metabolic signature could be induced by exposure to inflammatory particles like quartz and might be observed in the EBC via a change in the formate/acetate ratio.

Cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs) are genotoxic DNA lesions and mainly generated on thymine-thymine (T-T) dinucleotides upon UV irradiation. Regarding the sensitivity, specificity, and accuracy of analytical methods, it is of first choice to develop a reliable assay for simultaneous detection of these DNA lesions using liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, the dilemma is the low detection sensitivity of the phosphate-containing dimeric photoproducts even using most favorable negative-ion mode for LC-MS/MS analysis. Unexpectedly, we observed that the detection sensitivity of T-T CPD and 6-4PP could be significantly improved using formic acid/acetic acid (∼ppm) as an additive of the mobile phase for reversed-phase LC-MS/MS analysis. This is the first demonstration of the enhancement of LC-MS/MS signals by formic acid/acetic acid in negative-ion mode. Of note, these acidic agents are often used for positive-ion mode in LC-MS assays. Benefited from the developed method, we could quantify both T-T CPD and 6-4PP in mouse embryonic stem cells upon UVC irradiation at low dosage. This sensitive method is applicable to the screening and identification of genes involved in formation, signaling, and repair of UV lesion.

Metal-organic frameworks (MOFs) as new classes of proton-conducting materials have been highlighted in recent years. Nevertheless, the exploration of proton-conducting MOFs as formic acid sensors is extremely lacking. Herein, we prepared two highly stable 3D isostructural lanthanide(III) MOFs, {(M(μ 3 -HPhIDC)(μ 2 -C 2 O 4 ) 0.5 (H 2 O))⋅2 H 2 O} n (M=Tb (ZZU-1); Eu (ZZU-2)) (H 3 PhIDC=2-phenyl-1H-imidazole-4,5-dicarboxylic acid), in which the coordinated and uncoordinated water molecules and uncoordinated imidazole N atoms play decisive roles for the high-performance proton conduction and recognition ability for formic acid. Both ZZU-1 and ZZU-2 show temperature- and humidity-dependent proton-conducting characteristics with high conductivities of 8.95×10 -4 and 4.63×10 -4  S cm -1 at 98 % RH and 100 °C, respectively. Importantly, the impedance values of the two MOF-based sensors decrease upon exposure to formic acid vapor generated from formic aqueous solutions at 25 °C with good reproducibility. By comparing the changes of impedance values, we can indirectly determine the concentration of HCOOH in aqueous solution. The results showed that the lowest detectable concentrations of formic acid aqueous solutions are 1.2×10 -2  mol L -1 by ZZU-1 and 2.0×10 -2  mol L -1 by ZZU-2. Furthermore, the two sensors can distinguish formic acid vapor from interfering vapors including MeOH, N-hexane, benzene, toluene, EtOH, acetone, acetic acid and butane. Our research provides a new platform of proton-conductive MOFs-based sensors for detecting formic acid., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A facile approach for the construction of reagent-free electrochemical dehydrogenase-based biosensors is presented. Enzymes and cofactors (NAD + and Fe(CN) 6 3- ) were immobilized by modification of screen-printed carbon electrodes with graphene oxide (GO) and an additional layer of cellulose acetate. The sensor system was exemplarily optimized for an l-lactate electrode in terms of GO concentration, working potential, and pH value. The biosensor exhibited best characteristics at pH 7.5 in 100 mM potassium phosphate buffer at an applied potential of +0.250 V versus an internal pseudo Ag reference electrode. Thereby, sensor performance was characterized by a linear working range from 0.25 to 4 mM and a sensitivity of 0.14 μA mM -1 . The detection principle was additionally evaluated with three other dehydrogenases (d-lactate dehydrogenase, alcohol dehydrogenase, and formate dehydrogenase, respectively). The developed reagentless biosensor array enabled simultaneous and cross-talk free determination of l-lactate, d-lactate, ethanol, and formate.

Jabuticaba peel presents a high content of bioactive compounds such as phenolic acids, flavonoids, and anthocyanins, normally considered as a food residue. Nowadays, there is a great interesting in the recovery of bioactive compounds from food residue due to health benefits of the ingredients produced, environmental issues and economic aspects. For the success of phenolic compounds extraction, the solvent and pH influence recovery of these compounds. However, studies that evaluate the use of different weak acids bioactive compounds recovery are scarce. Thus, the aim of the present work was to evaluate the effect of formic, acetic, and phosphoric acids addition in the extraction solvent, to adjust the pH to 1.0, 2.0 and 3.0, in bioactive compounds recovery and antioxidant capacity of jabuticaba peel. The extracts were analyzed as antioxidant capacity (ORAC, FRAP), total phenols content monomeric anthocyanin's and a qualitative analysis of phenolics by Liquid Chromatography with mass spectrometry (LC-MS). The kind of acid used in the extraction process affected mainly in the extraction of anthocyanins. The acid that presented a better recovery of anthocyanin (3.4 mg/g raw material) and a better antioxidant capacity (ORAC) (841 μmol TE/g raw material) was formic acid in pH 1.0., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Fatty acids play important roles in the maintenance of cell membrane, viability and overall metabolism of wine yeasts (particularly Saccharomyces cerevisiae) during adverse winemaking conditions. We previously showed that linoleic acid supplementation markedly affect aroma compound production of S. cerevisiae wine strains. However, very little is known about how other commonly found fatty acids in grape juice modulate the growth and metabolism of S. cerevisiae. We aimed to determine the individual effect of five fatty acids on fermentation patterns and metabolism of two wine yeast strains (S. cerevisiae EC1118 and X5). Microvinification was performed at 15 °C by supplementing a grape juice (individually) with three different concentrations of saturated (palmitic acid), unsaturated (oleic, linoleic and γ-linolenic acids) and short-chain (hexanoic acid) fatty acids. Metabolite profiles of the resulting wines were determined using Gas-chromatography coupled to Mass-spectrometry (GC-MS). Our data show that the addition of γ-linolenic acid to the juice caused the production of higher amounts of amino and organic acids (except isoleucine and 2-oxoglutaric acid) in wines when fermented by EC1118, while palmitic acid supplementation showed similar trends when fermented by X5. The effect of linoleic acid was independent of yeast strains and we observed a global reduction of amino and organic acids (except pyruvic acid) while increased production of most of the fatty acids other than the supplemented ones. Our data clearly suggest that pre-fermentative supplementation of different fatty acids indeed influenced the growth and metabolism of wine yeasts in a different way. Thus, attention needs to be paid not only to the wine yeast strain used during the winemaking but also to the overall grape juice composition, including fatty acids, to obtain the desired wine characteristics., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The microbial assimilation of one-carbon (C1) gases is a topic of interest, given that products developed using this pathway have the potential to act as promising substrates for the synthesis of valuable chemicals via enzymatic oxidation or C-C bonding. Despite extensive studies on C1 gas assimilation pathways, their key enzymes have yet to be subjected to high-throughput evolution studies on account of the lack of an efficient analytical tool for C1 metabolites. To address this challenging issue, we attempted to establish a fine-tuned single-cell-level biosensor system constituting a combination of transcription factors (TFs) and several C1-converting enzymes that convert target compounds to the ligand of a TF. This enzymatic conversion broadens the detection range of ligands by the genetic biosensor systems. In this study, we presented new genetic enzyme screening systems (GESSs) to detect formate, formaldehyde, and methanol from specific enzyme activities and pathways, named FA-GESS, Frm-GESS, and MeOH-GESS, respectively. All the biosensors displayed linear responses to their respective C1 molecules, namely, formate (1.0-250 mM), formaldehyde (1.0-50 μM), and methanol (5-400 mM), and they did so with high specificity. Consequently, the helper enzymes, including formaldehyde dehydrogenase and methanol dehydrogenase, were successfully combined to constitute new versatile combinations of the C1-biosensors.

People are an important source of pollution indoors, through activities such as cleaning, and also from "natural" emissions from breath and skin. This paper investigates natural emissions in high-occupancy environments. Model simulations are performed for a school classroom during a typical summer in a polluted urban area. The results show that classroom occupants have a significant impact on indoor ozone, which increases from ~9 to ~20 ppb when the pupils leave for lunch and decreases to ~14 ppb when they return. The concentrations of 4-OPA, formic acid, and acetic acid formed as oxidation products following skin emissions attained maximum concentrations of 0.8, 0.5, and 0.1 ppb, respectively, when pupils were present, increasing from near-zero concentrations in their absence. For acetone, methanol, and ethanol from breath emissions, maximum concentrations were ~22.3, 6.6, and 21.5 ppb, respectively, compared to 7.4, 2.1, and 16.9 ppb in their absence. A rate of production analysis showed that occupancy reduced oxidant concentrations, while enhancing formation of nitrated organic compounds, owing to the chemistry that follows from increased aldehyde production. Occupancy also changes the peroxy radical composition, with those formed through isoprene oxidation becoming relatively more important, which also has consequences for subsequent oxidant concentrations., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

A facile and sensitive multi-residue detection approach of pressurized liquid extraction following high-performance liquid chromatography tandem mass spectrometry was established to detect the residues of adrenergic drugs, steroids, sedative, colorant and antioxidant in feed. The conditions employed for pressurized liquid extraction involved acetonitrile/ethyl acetate (1:1, v/v) as the extracting solvent, the temperature 80°C, two cycles and a static time of 10 min. The extraction was followed by a solid-phase extraction clean-up step. The separation of samples was done by C 18 column with the mobile phase of 5 mM ammonium acetate solution and acetonitrile with 0.1% formic acid. The limits of quantification ranged from 0.03 to 1 μg/kg, limits of detection were in a range of 0.01-0.5 μg/kg, and average recoveries were 70.4-98.6%. The pressurized liquid extraction procedure was optimized and overall method was validated in terms of sensitivity, linearity, selectivity, matrix effect, accuracy, recovery and stability of the target drugs in the pressurized liquid extraction extracts solution. The screening method was proved to be fast, selective, accurate and sensitive for screening drugs., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A fatal case of abuse of solvent containing mixture of toluene and methanol is presented. Concentrations of toluene, methanol and formic acid in a femoral venous blood sample were 20.1 mg/L, 210 mg/L and 25.2 mg/L, respectively. From the autopsy findings and toxicological examination, we concluded that the cause of death was poisoning by toluene and methanol.

In this work, we present the development of a method for the determination of acetate and formate in vegetable oils by ion chromatography with conductometric detection following their extraction from samples using a diluted KOH solution. The extraction procedure was optimized using a multivariate approach. The application of a 2 4 full factorial design showed that the mass of sample, extraction time, and KOH concentration presented significant influence on the extraction of both acetate and formate, whereas the temperature presented little influence on the process. As a result, we set the extraction temperature at 22 °C and performed the multivariate optimization of the other variables using a Doehlert design. The optimum conditions were: 4.8 g of sample, 8 mmol L -1 KOH solution and 19 min extraction time. Six samples of vegetable oils (soybean, corn, canola, sunflower and olive) were analyzed and recovery tests provided recovery percentages in the range of 82-118%., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Given that the peculiar redox behavior of ergothioneine involves a rapid regeneration process, the measurement of its precursor and redox metabolite hercynine could be particularly useful in assessing its role in oxidative stress or other biological processes. Thus, a LC-MS/MS method for the determination of hercynine concentrations in whole blood was developed. After lysis of red blood cells by cold water, samples were filtered on micro concentrators at a controlled temperature of 4 °C. The clear filtered fluid was then treated with diethylpyrocarbonate to derivatize hercynine for the analysis by LC-MS/MS. The derivatized analyte was isocratically separated as a carbethoxy derivative on a C18 column with a mobile phase of an aqueous 0.1% v / v formic acid and acetonitrile (95:5). Effluents were monitored by MRM transitions at m / z 270.28→95 and 273.21→95 for hercynine and its deuterated counterpart, respectively. No cross-talk between MRM transitions was observed and a good linearity was found within a range of 35⁻1120 nmol/L. The LOD and LOQ were, respectively, 10.30 and 31.21 nmol/L with an intraday and intermediate precision below 7%. The average hercynine concentration in whole blood from 30 healthy male volunteers (aged 77 ± 12 years) was 178.5 ± 118.1 nmol/L. Overall, the method is easy to perform, allowing a rapid and accurate assessment of whole blood concentrations of hercynine.

A 'missing source' of atmospheric formic acid is consistently observed during model-measurement comparisons, and evidence from multiple environments suggests a near-surface source. Soil emissions are considered to be a small formic acid source, but estimates are based on a single study from a tropical site. Here, we investigate soil emissions of organic acids from two soils - a ponderosa pine forest (Manitou Experimental Forest Observatory), and a managed lawn (Colorado State University) using a laboratory chamber. Both soils are a source of formic and acetic acids. Under ambient conditions, formic acid emissions are 0.11 (pine forest) and 0.15 (lawn) nmol m-2 s-1, and acetic acid emissions are 0.05 (pine forest) and 0.71 (lawn) nmol m-2 s-1. Only acetic acid emissions from the forest site correlate with CO2 fluxes, but all formic and acetic acid emissions increase exponentially with temperature. Increasing soil moisture only enhances acetic acid emissions from the forest. Considering this temperature and moisture dependence, we hypothesize that while equilibrium partitioning may contribute to the forest emissions, organic acid emissions from the lawn are likely driven by microbial activity. Lactic acid was emitted from both soils, but not quantified. The observed formic acid emissions are higher than previous measurements, but still low enough that soils are unlikely the 'missing source' of atmospheric organic acids, although the variability in the soil source is substantial. We contrast observations to previous parameterizations used in models, and present recommendations for modified parameterizations for formic and acetic acid emission.

Background: The preharvest application of Ca-containing foliar fertilizers can reduce the incidence of bitter pit (BP) in apples and improve fruit quality by increasing the Ca content and decreasing both the N content and the N/Ca ratio in fruits. In this study, we aimed to investigate the control efficacy of Ca-containing fertilizers on the incidence of BP and their effects on the Ca and N contents in bagged 'Fuji' apples by spraying foliar fertilizer containing calcium chloride (CaCl 2 ), calcium nitrate [Ca(NO 3 ) 2 ] or calcium formate [Ca(HCOO) 2 ] at an early stage, five days after full bloom (DAFB) and 40 DAFB, and at a late stage, 80 DAFB and 125 DAFB., Results: The incidences of BP were reduced significantly by 43.2-73.0%, and the efficacy of spraying at an early stage was significantly higher than that of spraying at a late stage. The Ca content of bagged apple fruits increased whereas the N content and N/Ca ratio decreased after spraying Ca-containing foliar fertilizers; however, the Ca content, N content and N/Ca ratio of apple leaves were differentially influenced., Conclusion: Foliar fertilizer containing CaCl 2, Ca(NO 3 ) 2 or Ca(HCOO) 2 can be used at an early stage to control BP in apple and improve the quality of bagged apple fruits. © 2018 Society of Chemical Industry., (© 2018 Society of Chemical Industry.)

Evaluation of the level of contamination of environment by specific components of tobacco smoke (ambient and indoor level of Formic Acid) consider the volume and physico-chemical space parameters of the "passive smokers" location. By method of gasliquid capillary chromatography the content of Formic acid in the air samples of Tobacco Smoke was revealed. Investigations are carried on chromatograph PPE-Millipo-Waters (USA) provided with fireionized detector. Estimation of the corrected volume of holding is conducted with the help of integration Data Module Model 730. Temperature of the environment 18,0°C. The tobacco smoke volume was taked and analyzed from begining of the experiment (after the second enfale in 3 min, 5 min and 10 minuts in the distance of 2, 4 and 6 m. from lighting cigarette. Our data shows that the level Formic Acid in the Tobacco smoke samples taken an 3,0 min after beginning of the experiment (distance 4) was practically the same as a distance 6 m. After 10 min of exposition (same distance) the level of Formic Acid did not exceed tracing values. Due to airdynamic and physiochemical peculiarities Formic Acid has different rate of migration and cover different distance. The obtained data is very important from the point of ecological assessment of the environment and individual sensitivity in the components of ambient and indoor tobacco smoke.

A female in her late teens purposely ingested alcohol fuel containing methanol to commit suicide, which she admitted on social media. She was found in distress by her parents and died at the hospital some hours later. Autopsy revealed swelling of the brain and edematous and congestive lungs. No other trauma or unusual findings were revealed at autopsy. Methanol was detected upon routine screening for alcohols by headspace gas chromatography with flame-ionization detection. To confirm the presence of methanol and its metabolite formic acid, a method with detection by mass spectrometry was used. Methanol and formic acid were quantitated in body fluids and tissues by headspace gas chromatography with flame-ionization detection. Formic acid was converted to isopropyl formate by reaction with isopropanol and concentrated sulfuric acid. Acetonitrile was used as the internal standard. The methanol and formic acid concentrations were analyzed in peripheral blood, heart blood, cerebrospinal fluid, liver, kidney, spleen, pancreas, lung, muscle, and fat. Successful confirmation and quantitation of methanol and formic acid, a methanol metabolite, in postmortem specimens was achieved on an uncommon case of suicide by methanol ingestion., (Copyright © 2018. Published by Elsevier B.V.)

A simple and effective sample preparation process based on miniaturized matrix solid-phase dispersion was developed for simultaneous determination of phenolic acids (gallic acid, chlorogenic acid, ferulic acid, 3,5-dicaffeoylqunic acid, 1,5-dicaffeoylqunic acid, rosmarinic acid, lithospermic acid, and salvianolic acid B), flavonoids (kaempferol-3-O-rutinoside, calycosin, and formononetin), lactones (ligustilide and butyllidephthalide), monoterpenoids (paeoniflorin), phenanthraquinones (cryptotanshinone), and furans (5-hydroxymethylfurfural) in Naoxintong capsule by ultra high-performance liquid chromatography. The optimized condition was that 25 mg Naoxintong powder was blended homogeneously with 100 mg Florisil PR for 4 min. One milliliter of methanol/water (75:25, v/v) acidified by 0.05% formic acid was selected to elute all components. It was found that the recoveries of the six types of components ranged from 61.36 to 96.94%. The proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography was successfully applied to simultaneous determination of the six types of components in Naoxintong capsules. The results demonstrated that the proposed miniaturized matrix solid-phase dispersion coupled with ultra high-performance liquid chromatography could be used as an environmentally friendly tool for the extraction and determination of multiple bioactive components in natural products., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Formic acid is corrosive, and a sensitive and selective sensor could be useful in industrial, medical, and environmental settings. We present a chemiresistor for detection of formic acid composed of single-walled carbon nanotubes (CNTs) and nickel bis( ortho-diiminosemiquinonate) (1), a planar metal complex that can act as a ditopic hydrogen-bonding selector. Formic acid is detected in concentrations as low as 83 ppb. The resistance of the material decreases on exposure to formic acid, but slightly increases on exposure to acetic acid. We propose that 1 assists in partial protonation of the CNT by formic acid, but the response toward acetic acid is dominated by inter-CNT swelling. This technology establishes CNT-based chemiresistive discrimination between formic and acetic acid vapors.

Considering the side effects of current anti-inflammatory drugs, novel therapeutic agents are desired. We have succeeded in separating flavonoid-rich fractions with anti-inflammatory effect from fenugreek seeds (Trigonella foenum-graecum L.). In this work, we aimed to carry out further fractionation to find active anti-inflammatory subfractions. Trigonelline content of the plant was determined by spectrophotometric method. Fenugreek seeds were extracted consecutively with petroleum ether, acidified chloroform (ACC), alkaline chloroform (AKC), methanol, and water. ACC fraction, which had exhibited the highest anti-inflammatory effect, was further fractionated using column chromatography. Obtained subfractions were evaluated using carrageenan-induced paw edema (CIPE) method. Animals were pretreated by test compounds, and after 30 minutes edema was induced by subcutaneous injection of 100 µl of 1% w/v carrageenan into the right paw of animals. Volume difference of both paws was measured at different times after carrageenan injection. The concentration of trigonelline was determined as 16.2%. ACC fraction inhibited paw edema significantly in comparison to control (p < .05). Four subfractions (dry weight percentage basis) were selected for pharmacological study. F3 subfraction exhibited the greatest inhibition at 15 mg/kg (p < .001). ACC fraction and F4 significantly inhibited paw edema at doses of 5, 10, and 15 mg/kg (p < .001). Phytochemical studies indicated the presence of flavonoids in ACC and active subfractions. Further separation can lead to finding active components from active subfractions, which probably belong to flavonoid phytochemicals. Considering the gastroprotective effect of fenugreek, we hope the separated fractions also would be free of gastrointestinal side effects.

A technique for quantitative determination of low molecular weight organic acids in saliva by the method of capillary electrophoresis has been developed. The method was tested on volunteers, divided into 3 groups: the main one (breast cancer, n=21), the comparison group (fibroadenomas, n=29) and the control group (conditionally healthy, n=26). It is shown that the concentration of lactic, acetic and propionic acids increases uniformly when passing from the control group to the comparison group, and then to the main group. Against the background of breast cancer, the concentration of oxalic and formic acids decreases in comparison with the control, whereas in fibroadenomas the concentration of oxalic acid decreases, and the formic acid grows. In general, the proposed method can be a valuable tool in the study of metabolic changes associated with cancer., Competing Interests: The authors declare no conflict of interest.

Drug-induced off-target cardiotoxicity, particularly following anti-cancer therapy, is a major concern in new drug discovery and development. To ensure patient safety and efficient pharmaceutical drug development, there is an urgent need to develop more predictive cell model systems and distinct toxicity signatures. In this study, we applied our previously proposed repeated exposure toxicity methodology and performed 1 H NMR spectroscopy-based extracellular metabolic profiling in culture medium of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) exposed to doxorubicin (DOX), an anti-cancer agent. Single exposure to DOX did not show alteration in the basal level of extracellular metabolites while repeated exposure to DOX caused reduction in the utilization of pyruvate and acetate, and accumulation of formate compared to control culture medium. During drug washout, only pyruvate showed reversible effect and restored its utilization by hiPSC-CMs. On the other hand, formate and acetate showed irreversible effect in response to DOX exposure. DOX repeated exposure increased release of lactate dehydrogenase (LDH) in culture medium suggesting cytotoxicity events, while declined ATP levels in hiPSC-CMs. Our data suggests DOX perturbed mitochondrial metabolism in hiPSC-CMs. Pyruvate, acetate and formate can be used as metabolite signatures of DOX induced cardiotoxicity. Moreover, the hiPSC-CMs model system coupled with metabolomics technology offers a novel and powerful approach to strengthen cardiac safety assessment during new drug discovery and development.

Lettuce is an important part of the diet in Europe. The permitted levels of pesticides in lettuce are strictly regulated and there is growing urge among food safety authorities to analyse pesticide metabolites as well. Azoxystrobin is one of pesticides that is frequently detected in lettuce. Although there are several analytical methods for the determination of azoxystrobin in lettuce, a sensitive method for the determination of its metabolites in lettuce is lacking. This study aimed at developing an extraction and LC-MS/MS method for the simultaneous determination of azoxystrobin, and its metabolites azoxystrobin free acid and 2-hydroxybenzonitrile in lettuce. Accelerated solvent extraction, QuEChERS extraction, and shaking extraction were compared using various solvents. The final method consisted of shaking freeze-dried sample in 0.1% formic acid in 80% aqueous acetonitrile. The selected method was validated by spiking each analyte at 125 ng/g and 500 ng/g. The method resulted in acceptable recovery for 2-hydroxybenzonitrile, azoxystrobin free acid, and azoxystrobin, with a RSD of <10%. The matrix-matched calibration curve for each analyte was linear over the range of quantification, with a correlation coefficient ≥0.98. The method was sensitive for the determination of 2-hydroxybenzonitrile, azoxystrobin free acid, and azoxystrobin, with limits of quantification of 0.36, 0.48, and 0.68 ng/g dry weight, respectively. The method was successfully applied to quantify 2-hydroxybenzonitrile, azoxystrobin free acid, and azoxystrobin in greenhouse-grown lettuce.

A novel method based on liquid-liquid extraction with subsequent gas chromatography separation and mass spectrometric detection (GC-MS) for the quantification of organic carbonates in cell culture materials is presented. Method parameters including the choice of extraction solvent, of extraction method and of extraction time were optimised and the method was validated. The setup allowed for determination within a linear range of more than two orders of magnitude. The limits of detection (LODs) were between 0.0002 and 0.002 mmol/L and the repeatability precisions were in the range of 1.5-12.9%. It could be shown that no matrix effects were present and recovery rates between 98 and 104% were achieved. The methodology was applied to cell culture models incubated with commercial lithium ion battery (LIB) electrolytes to gain more insight into the potential toxic effects of these compounds. The stability of the organic carbonates in cell culture medium after incubation was studied. In a porcine model of the blood-cerebrospinal fluid (CSF) barrier, it could be shown that a transfer of organic carbonates into the brain facing compartment took place. Graphical abstract Schematic setup for the investigation of toxicity of lithium ion battery electrolytes.

Spatial trends of acetate (Ac - ) and formate (Fo - ) were determined in surface snow samples along a coastal-inland transect (180km) in the ice cap region at Princess Elizabeth Land and along a coastal transect in the Amery Ice Shelf (130km), East Antarctica. Variations in both Ac - and Fo - seem to be unrelated to the acidity of snow. Ionic balance determined for the snow samples indicate the availability of HNO 3 that could undergo photolysis to produce hydroxyl radical (OH), one of the major reactants involved in oxidation reactions with organic matter. The strong positive correlations between Ac - and NO 3 - in snow from both regions indicate that NO 3 - mediated OH-oxidation of organic compounds in snow could be an important source of Ac - within the snowpack. On the other hand, negative correlation between Fo - and NO 3 - might indicate that sources other than OH-oxidation of organic matter may be dominant in the case of Fo - . Higher Ac - concentrations in the ice cap compared to the ice shelf correspond with long-range transport of biomass burning emissions to the ice cap region. Interaction of Ac - and Fo - with alkaline minerals could lead to their stability in the snowpack and minimize their loss from the snow surface. Resident microbial communities could also influence the budget of the carboxylic acids in snow., (Copyright © 2017. Published by Elsevier B.V.)

Chemical cues that elicit orientation by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), are of interest because it is the primary vector of the causal pathogen of citrus greening disease. Non-pesticidal control methods for D. citri remain a high priority for the citrus industry. While searching for semiochemicals that may be involved in orientation to host plants, we previously identified a blend of formic and acetic acids that stimulated substrate probing by D. citri. Here, we applied geometric mixture designs and response surface modeling to identify and optimize a 3-component blend that further increased the number of salivary sheaths produced by D. citri on a wax substrate containing a 3.5:1.6:1 blend of formic acid, acetic acid, and p-cymene, respectively. No evidence was found for remote orientation by D. citri adults through olfaction to the phagostimulant blends. Increased probing in response to the presence of phagostimulants in the wax matrix occurred after contact with the substrate. Yellow wax beads always attracted more D. citri adults and received more probes compared with white wax beads. Yellow beads containing the 3-component blend of phagostimulants were probed by D. citri 2 to 3 times more often compared with yellow beads alone. The phagostimulant effect also was tested by covering wax beads containing the 3-component blend with a plastic film to minimize olfaction or contact chemoreception by antennation. The plastic film did not affect the probing response, thus suggesting that chemosensation was associated with mouthparts and not olfactory receptors. Salivary sheaths produced in wax beads containing the phagostimulant blend were 4.5 times longer than sheaths produced in beads without tastants. This phenomenon might be used to improve a trap, design an attract-and-kill product, or enhance other means of managing D. citri and citrus greening disease.

In the present work, NAD(+)-dependent formate dehydrogenase (FDH), encoded by fdh gene from Candida boidinii was successfully displayed on Escherichia coli cell surface using ice nucleation protein (INP) from Pseudomonas borealis DL7 as an anchoring protein. Localization of matlose binding protein (MBP)-INP-FDH fusion protein on the E. coli cell surface was characterized by SDS-PAGE and enzymatic activity assay. FDH activity was monitored through the oxidation of formate catalyzed by cell-surface-displayed FDH with its cofactor NAD(+), and the production of NADH can be detected spectrometrically at 340nm. After induction for 24h in Luria-Bertani medium containing isopropyl-β-d-thiogalactopyranoside, over 80% of MBP-INP-FDH fusion protein present on the surface of E. coli cells. The cell-surface-displayed FDH showed optimal temperature of 50°C and optimal pH of 9.0. Additionally, the cell-surface-displayed FDH retained its original enzymatic activity after incubation at 4°C for one month with the half-life of 17days at 40°C and 38h at 50°C. The FDH activity could be inhibited to different extents by some transition metal ions and anions. Moreover, the E. coli cells expressing FDH showed different tolerance to solvents. The recombinant whole cell exhibited high formate specificity. Finally, the E. coli cell expressing FDH was used to assay formate with a wide linear range of 5-700μM and a low limit of detection of 2μM. It is anticipated that the genetically engineered cells may have a broad application in biosensors, biofuels and cofactor regeneration system., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Hexamethylene triperoxide diamine (HMTD) is an easily synthesized and highly sensitive organic peroxide frequently used as a primary explosive. The vapor pressure of HMTD is very low, impeding vapor detection, especially when compared to other peroxide explosives, such as triacetone triperoxide (TATP) or diacetone diperoxide (DADP). Despite this fact, HMTD has a perceptible odor that could be utilized in the indirect detection of HMTD vapor. Headspace measurements above solid HMTD samples confirm that HMTD readily decomposes under ambient conditions to form highly volatile products that include formic acid, ammonia, trimethylamine and formamides. The presence and quantity of these compounds are affected by storage condition, time, and synthetic method, with synthetic method having the most significant effect on the content of the headspace. A kinetic study of HMTD decomposition in solution indicated a correlation between degradation rate and the presence of decomposition species identified in the headspace, and provided further insight into the mechanism of decomposition. The study provided evidence for a proton assisted decomposition reaction with water, as well as an intramolecular decomposition process facilitated by the presence of water., (Published by Elsevier B.V.)

Herein, we present a rare case of suicidal intoxication with carbon monoxide produced via reaction of formic and sulphuric acid with additional toxic effect of formic acid. The deceased was a 22-year-old men found dead in the bathroom locked from the inside. A bucket filled with liquid was found next to him, together with an almost empty canister labeled "formic acid" and another empty unlabeled canister. The postmortem examination revealed corrosive burns of the face, neck and chest, cherry-pink livor mortis, corrosive injury to the oropharyngeal area and trachea, subpleural petechiae, 100 mL of blood in stomach and superficial erosions of stomach mucosa. Toxicology analysis revealed 30% of carboxyhemoglobin in the femoral blood and the presence of the formic acid in various samples. Quantitative analysis of formic acid was performed by measuring methyl ester derivative of formic acid by using headspace gas chromatography with flame ionization detection. The highest concentration of formic acid was measured in the lungs (0.55 g/kg), gastric content (0.39 g/L), and blood (0.28 g/L). In addition, it was established that content of the unlabeled canister had a pH value of 0.79 and contained sulphuric ions. Morphological and toxicology findings suggested that the main route of exposure to formic acid was inhalation of vapors with a possible ingestion of only small amount of liquid acid. The cause of death was determined to be combined intoxication with carbon monoxide and formic acid.

To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

Purpose: The aim of this study was to assess the effect of perioperative oral administration of synbiotics on the surgical outcome in patients undergoing laparoscopic colorectal resection., Methods: In this single-center randomized, controlled trial, patients scheduled to undergo elective laparoscopic colorectal surgery were eligible to participate and randomly assigned to a synbiotics group or a control group. The primary study outcome was the development of infectious complications, particularly surgical site infection (SSI), within 30 days of surgery., Results: In this study, 379 patients were enrolled and randomly assigned (173 to the synbiotics group and 206 to the control group), of whom 362 patients (168 to the synbiotics group and 194 to the control group) were eligible for this study. SSI occurred in 29 (17.3%) patients in the synbiotics group and 44 (22.7%) patients in the control group (OR: 0.761, 95% CI 0.50-1.16; p = 0.20). Overall, the rate of postoperative complications, including anastomotic leakage, did not differ significantly between the two groups. Synbiotics treatment reversed the changes in fecal bacteria and organic acids after surgery and suppressed the increases in potentially pathogenic species, such as Clostridium difficile., Conclusion: The efficacy of perioperative administration of synbiotics was not validated as a treatment for reducing the incidence of infectious complications after laparoscopic colorectal resection. However, the microbial imbalance, in addition to the reduction in organic acids, could be improved by perioperative synbiotics treatment.

Objectives: To investigate the salivary anionic changes of patients with nasopharyngeal carcinoma (NPC) treated by radiotherapy., Material and Methods: Thirty-eight patients with T1-4, N0-2, M0 NPC received conventional radiotherapy. Stimulated whole saliva was collected at baseline and 2, 6 and 12 months after radiotherapy. Salivary anions levels were measured using ion chromatography., Results: A reduction in stimulated saliva flow and salivary pH was accompanied by sustained changes in anionic composition. At 2 months following radiotherapy, there was a significant increase in chloride, sulphate, lactate and formate levels while significant reductions in nitrate and thiocyanate levels were found. No further changes in these anion levels were observed at 6 and 12 months. No significant changes were found in phosphate, acetate, or propionate levels throughout the study period., Conclusions: Conventional radiotherapy has a significant and prolonged impact on certain anionic species, likely contributing to increased cariogenic properties and reduced antimicrobial capacities of saliva in NPC patients post-radiotherapy.

Pool sizes of short-chain fatty acids (formate, acetate, propionate, and butyrate), hydrogen, and carbon monoxide were assayed in digesting sludge from four different methanogenic reactors degrading either sewage sludge or agricultural products and wastes at pH 8.0 and 40 or 47 °C. Free reaction energies were calculated for the respective degradation reactions involved, indicating that acetate, propionate, and butyrate degradation all supplied sufficient energy (-10 to -30 kJ per mol reaction) to sustain the microbial communities involved in the respective processes. Pools of formate and hydrogen were energetically equivalent as electron carriers. In the sewage sludge reactor, homoacetogenic acetate formation from H2 and CO2 was energetically feasible whereas syntrophic acetate oxidation appeared to be possible in two biogas reactors, one operating at enhanced ammonia content (4.5 g NH4 (+)-N per l) and the other one at enhanced temperature (47 °C). Maximum capacities for production of methanogenic substrates did not exceed the consumption capacities by hydrogenotrophic and aceticlastic methanogens. Nonetheless, the capacity for acetate degradation appeared to be a limiting factor especially in the reactor operating at enhanced ammonia concentration.

The present study aims to identify the renewable resources available in Brazil such as açai seed, coconut husks, coffee husks, rice husks, eucalyptus sawdust, grass, soy peel, bamboo, banana stems and banana stalks. To identify such renewable energy sources, samples were examined for their physical and chemical characteristics using X-ray diffraction (XRD), proximate and ultimate analyses, thermogravimetric analysis (TGA), calorific value determination, near-infrared (NIR) spectroscopy, UV spectroscopy, high-pH anion-exchange chromatography (HPAEC-PAD) and accelerated solvent extraction (ASE). Among the biomasses, açai and coffee exhibited higher total sugar content, 67.70% and 62.55%, respectively. Sawdust exhibited low ash, along with the highest calorific value and lignin content. The highest glucose contents were observed in bamboo (44.65%) and sawdust (38.80%). The maximum yield for the bioproducts levulinic acid (LA), formic acid (FA) and furfural were estimated; açai exhibited the highest yield of LA and FA, while coffee exhibited the best furfural yield. All of these properties indicate that the residues are potential candidates for bioenergy production., (Copyright © 2015 Elsevier B.V. All rights reserved.)

The analysis of amino acids has become a central task in many aspects. While amino acid analysis has traditionally mainly been carried out using either gas chromatography (GC) in combination with flame ionization detection or liquid chromatography (LC) with either post-column derivatization using ninhydrin or pre-column derivatization using o-phthalaldehyde, many of today's analysis platforms are based on chromatography in combination with mass spectrometry (MS). While derivatization is mandatory for the GC-based analysis of amino acids, several LC platforms have emerged, particularly in the dawn of targeted metabolite profiling using hydrophilic interaction liquid chromatography (HILIC) coupled to MS, allowing the analysis of underivatized amino acids. Among the numerous analytical platforms available for amino acid analysis today, we here compare three prominent approaches, being GC-MS and LC-MS after amino acid derivatization using chloroformate and HILIC-MS of underivatized amino acids. We compare and discuss practical issues as well as performance characteristics, e.g., the use of (13)C-labeled internal standards, of the different platforms and present data on their practical implementation in our laboratory. Finally, we compare the real-life applicability of all three platforms for a complex biological sample. While all three platforms are very-well suited for the analysis of complex biological samples they all show advantages and disadvantages for some analytes as discussed in detail in this manuscript., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Streptococcus thermophilus is a lactic acid bacterium and used as starter culture in the dairy industry, mainly in the manufacture of yoghurt, with Lactobacillus delbrueckii subsp. bulgaricus. It produces lactic acid as a major fermentation end product and some carbonyl compounds through sugar metabolism. The level of metabolites could be improved using molecular biotechnology. The genes of als, encoding α-acetolactate synthase (Als), the pflA, encoding pyruvate-formate lyase activating enzyme (PflA), and the adhB which encodes alcohol dehydrogenase (AdhB) of S. thermophilus NCFB2393 strain were amplified by polymerase chain reaction and separately cloned into the overexpression vector pNZ276 under the control of the lacA promoter. The strains were transformed individually with the constructed plasmids. Their abilities to generate important metabolites such as pyruvate, lactate, formate, acetaldehyde, acetoin, ethanol, and 2,3-butanediol in LM17 medium were analyzed using high-performance liquid chromatography. High level of 2,3-butanediol was obtained by overexpressing the als gene. The level of formate increased slightly by overexpressing the pflA gene. The overexpression of the adhB gene, on the other hand, resulted in a significant increase in the ethanol level.

One of the major problems of airport operation is the impact of pollution caused by runoff waters. Runoff waters at an airport may contain high concentrations of different contaminants resulting from various activities of its operation. High quantities of aircraft de-icing/anti-icing fluids are used annually at airports worldwide. Aircraft de-icers and anti-icers may have negative environmental impacts, but their effects on aquatic organisms are virtually unknown. In order to address this issue, aircraft de-icers, pavement de-icers and wastewater samples were obtained from a regional airport. To evaluate the toxicity of wastewater samples and aircraft de-icing/anti-icing fluids (ADAFs), two bio-tests were performed: the Lemna growth inhibition test according to OECD guideline 221 and the luminescent bacteria test according to ISO guideline 11348-2. In the Lemna growth inhibition test, phytotoxicity was assessed using the endpoints frond number and frond area. The luminescent bacteria test involved the marine bacterium Vibrio fischeri. The estimates of effective concentrations (EC50) values were determined using the free software R and the "drc" library. Aquatic plants and marine bacteria showed a higher sensitivity towards ADAFs than to wastewater samples. Experiments showed that aircraft de-icing/anti-icing fluids and wastewater samples were relatively more toxic towards Lemna gibba L. in comparison to V. fischeri.

Introduction: Illegal alcohol production remains as a common issue worldwide. Methanol poisoning mostly occurs because of the methanol used in production of counterfeit alcohol instead of ethyl alcohol due to its low price or by drinking the liquids containing methyl alcohol. Pectolytic enzymes results in an increase of methanol levels in many fermentation products such as ciders or wines. Methanol poisonings are infrequently encountered in forensic medicine practice. However, sporadic cases due to methanol intoxication as well as epidemic cases have been reported. In this study, we aimed to identify existence of methanol and its metabolites in illegally produced alcoholic beverages used in Antakya region., Material and Methods: Twelve legally produced alcohol samples and Fifty-six different illegally produced alcohol samples were collected from the markets and local producers. Existence of methanol, formic acid, methyl amine, methyl formate and trioxan were determined using GC-MS method in these samples., Results: Fifty-six different illegal alcohol samples were analyzed in this study and methanol was detected in 39 (75%) of samples. Formic acid was detected in 3, formamide in 1, methyl amine in 6, methyl formate in 10 and trioxan in 2 samples., Conclusion: Overwhelming majority of illegal alcoholic beverages was detected to contain methanol. Interestingly this study also revealed the presence of trioxane, which has not previously reported among toxic agents in illegal alcohol samples., (Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.)

A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45-0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = -0.95 to -0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate.

Degradation of aqueous 3,4-dichloroaniline (3,4-DCA) was conducted in a novel dielectric barrier discharge (DBD) plasma reactor. The factors affecting the degradation efficiency of 3,4-DCA and the degradation mechanism of 3,4-DCA were investigated. The experimental results indicated that the degradation efficiency of 3,4-DCA increased with increasing input power intensity, and the degradation of 3,4-DCA by the novel DBD plasma reactor fitted pseudo-first-order kinetics. Higher degradation efficiency of 3,4-DCA was observed in acidic conditions. The degradation efficiency of 3,4-DCA, the removal rate of total organic carbon (TOC), and the detected Cl(-) increased dramatically with adding Fe(2+) or Fe(3+). Degradation of 3,4-DCA could be accelerated or inhibited in the presence of H2O2 depending on the dosage. Several degradation intermediates of 3,4-DCA such as 1,2-dichlorobenzene, 2-chloro-1,4-benzoquinone, 3,4-dichlorophenyl isocyanate, 2-chlorohydroquinone, 3,4-dichloronitrobenzene, and 3,4-dichlorophenol were identified by gas chromatography mass spectrometry (GC-MS) analysis. Based on the identification of aromatic intermediates, acetic acid, formic acid, oxalic acid, and Cl(-) released, a possible mineralization pathway of 3,4-DCA was proposed.

Objectives: Indoor air quality (IAQ) is a major concern, because people on average spend the vast majority of their time indoors and they are repeatedly exposed to indoor air pollutants. In this study, to assess indoor air quality in Chiba City, gaseous chemical compounds were surveyed using four types of diffusive sampler., Methods: Gaseous chemical compounds such as carbonyls, volatile organic compounds (VOC), acid gases, basic gases, and ozone were measured in indoor and outdoor air of 50 houses throughout Chiba City in winter and summer. Four types of diffusive sampler were used in this study: DSD-BPE/DNPH packed with 2,4-dinitrophenyl hydrazine and trans-1,2-bis(2-pyridyl)ethylene-coated silica for ozone and carbonyls; VOC-SD packed with Carboxen 564 particles for volatile organic compounds; DSD-TEA packed with triethanolamine-impregnated silica for acid gases; and DSD-NH3 packed with phosphoric acid-impregnated silica for basic gases., Results: Almost all compounds in indoor air were detected at higher concentrations in summer than in winter. However, the nitrogen dioxide concentration in indoor air particularly increased only in winter, which well correlated with the formic acid concentration (correlation coefficient=0.974). The compound with the highest concentrations in indoor air was p-dichlorobenzene, with recorded levels of 13,000 μg m(-3) in summer and 1,100 μg m(-3) in winter in indoor air., Conclusions: p-Dichlorobenzene in summer and nitrogen dioxide in winter are detected at markedly high concentrations. Pollution control and continuous monitoring of IAQ are indispensable for human health.