RESUMO
Blends of biodiesel and high-carbon alcohols have the potential to increase the rate of biofuel use in diesel engines, while reducing harmful and toxic compounds such as polycyclic aromatic hydrocarbons (PAHs). Since biodiesel and alcohols do not contain aromatic ingredients in their chemical structures, this study examined biodiesel blends with propanol, n-butanol, and 1-pentanol (5 %, 20 % and 35 % by vol.) and the effects of these aromatic-free fuels on regulated emissions, PAH formation and toxicity as compared to straight diesel fuel in a diesel engine operating at a constant speed and varying engine loads. PAH samples were meticulously processed and extensively analyzed using rigorous analytical chemistry methodology (gas chromatography-mass spectrometry (GC-MS)). Biodiesel and biodiesel-alcohol blends significantly reduced NOx emissions and the level of formation of PAHs and toxicity levels when compared to diesel fuel. Overall, adding 5 % alcohol to biodiesel decreased total PAH emissions. However, with the exception of 20 % propanol, adding 20 % and 35 % alcohol to biodiesel increased total PAH emissions as compared to neat biodiesel. In contrast, all blended fuels resulted in a decrease in the toxicity of PAH compounds (up to 70 %) and the percentage of higher-ring PAHs. Among higher alcohols, propanol blends stood out as reducing PAH formation as compared to n-butanol and pentanol blends. Overall, biodiesel-alcohol blends that emit less carcinogenic pollutants and primarily low-rings PAHs were found to be advantageous for reducing the likelihood of wetstacking in diesel engines under low load or cold operating conditions.
Assuntos
Poluentes Atmosféricos , Poluentes Ambientais , Hidrocarbonetos Policíclicos Aromáticos , 1-Butanol/análise , 1-Propanol/análise , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Biocombustíveis/análise , Butanóis/análise , Carbono/análise , Poluentes Ambientais/análise , Etanol/análise , Gasolina/análise , Pentanóis , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Emissões de Veículos/análiseRESUMO
The present study investigated the chemical constituents from the dry seeds of Hydnocarpus anthelminthica. The compounds were isolated and purified from the dry seeds of H. anthelminthica by various chromatographic techniques including column chromatography over silica gel and Sephadex LH-20 and reversed-phase HPLC. Their structures were identified by spectroscopic analysis. The in vitro cytotoxic activities were determined by MTT assay. Ten compounds were isolated and identified as 2-(4-hydroxy-3,5-dimethoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol(1), threo-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol(2), erythro-1,2-bis-(4-hydroxy-3-methoxyphenyl)-propane-1,3-diol(3), 2-(4-hydroxy-3-methoxyphenyl)-3-(2-hydroxy-5-methoxyphenyl)-3-oxo-1-propanol(4), 3-hydroxy-2-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)-propan-1-one(5), chrysoeriol(6), evofolin B(7), apigenin-3'-methoxy-7-O-rutinoside(8), luteolin(9), and vitexin(10). Compound 1 is a new compound. Compounds 4 and 5 were isolated from this genus for the first time. All compounds showed no significant cytotoxic activity.
Assuntos
1-Propanol , Propano , 1-Propanol/análise , Propano/análise , Sementes/químicaRESUMO
Cyanide is a powerful and rapidly acting poison. In Japan, cyanide poisoning is rare, and regular cyanide testing can be costly and time consuming. In contrast, alcohol analysis is routinely performed in most forensic laboratories. In this study, we attempted to develop a method for the simultaneous quantification of cyanide and alcohols in blood using headspace gas chromatography (HS-GC). As nitrogen-phosphorus detection (NPD) is more sensitive to hydrogen cyanide than mass spectrometry (MS), a Deans switch was used to switch the detectors during a single run. The separation provided by three analytical columns, PoraBOND Q, CP-Sil 5 CB, and HP-INNOWax, was investigated, and PoraBOND Q was selected. The use of HS-GC-MS/NPD with a Deans switch enabled the simple and simultaneous quantification of cyanide, ethanol, and 1-propanol. Eighteen other volatile compounds were detected in the SIM/scan mode of the MS.
Assuntos
1-Propanol , Cianetos , Humanos , 1-Propanol/análise , Etanol/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Nitrogênio , FósforoRESUMO
A quite intriguing subject being intensively researched in the forensic toxicology field is the source of postmortem determined blood ethanol concentration: antemortem ingestion or postmortem microbial production. Our previous research on microbial ethanol production has reported a quantitative relationship between the ethanol and the higher alcohols and 1-butanol produced by Escherichia coli, Clostridium perfrigens, and Clostridium sporogenes. In this contribution, we continue our research reporting on the following: (i) the patterns of ethanol, higher alcohols, and 1-butanol production by the microbes Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecalis (all being aerobic/facultative anaerobic species, common corpse's colonizers, and ethanol producers), under controlled laboratory conditions, (ii) the mathematical modeling, with simple mathematical equations, of the correlation between ethanol concentration and the other studied alcohols' concentrations, by performing multiple linear regression analysis of the results, and (iii) the applicability of the constructed models in microbial cultures developed under different temperature than that used to build the models, in denatured blood cultures and in real postmortem cases. The aforementioned alcohols were proved to be all indicators of ethanol production, both in qualitative and quantitative terms. 1-Propanol was the most significant alcohol in modeling microbial ethanol production, followed by methyl-butanol. The K. pneumoniae's models achieved the best scoring in applicability (E < 40%) compared to the S. aureus and E. faecalis models, both at laboratory microbial cultures at 37 °C and real postmortem cases. Overall, a noteworthy accuracy in estimating the microbial ethanol in cultures and autopsy blood is achieved by the employed simple linear models.
Assuntos
Sangue/microbiologia , Enterococcus faecalis/química , Etanol/análise , Klebsiella pneumoniae/química , Staphylococcus aureus/química , 1-Butanol/análise , 1-Propanol/análise , Aerobiose , Anaerobiose , Autopsia , Concentração Alcoólica no Sangue , Butanóis/análise , Humanos , Modelos Teóricos , Pentanóis/análiseRESUMO
BACKGROUND: Real-time photoacoustic gas monitoring is used for personnel exposure and environmental monitoring, but its accuracy varies when organic solvents such as alcohol contaminate measurements. This is problematic for anesthetic gas measurements in hospitals, because most disinfectants contain alcohol, which could lead to false-high gas concentrations. We investigated the cross-sensitivities of the photoacoustic gas monitor Innova 1412 (AirTech Instruments, LumaSense, Denmark) against alcohols and alcoholic disinfectants while measuring sevoflurane, desflurane and isoflurane in a laboratory and in hospital during surgery. METHODS: 25 mL ethyl alcohol was distributed on a hotplate. An optical filter for isoflurane was used and the gas monitor measured the 'isoflurane' concentration for five minutes with the measuring probe fixed 30 cm above the hotplate. Then, 5 mL isoflurane was added vaporized via an Anesthetic Conserving Device (Sedana Medical, Uppsala, Sweden). After one-hour measurement, 25 mL isopropyl alcohol, N-propanol, and two alcoholic disinfectants were subsequently added, each in combination with 5 mL isoflurane. The same experiment was in turn performed for sevoflurane and desflurane. The practical impact of the cross-sensitivity was investigated on abdominal surgeons who were exposed intraoperatively to sevoflurane. A new approach to overcome the gas monitor's cross-sensitivity is presented. RESULTS: Cross-sensitivity was observed for all alcohols and its strength characteristic for the tested agent. Simultaneous uses of anesthetic gases and alcohols increased the concentrations and the recovery times significantly, especially while sevoflurane was utilized. Intraoperative measurements revealed mean and maximum sevoflurane concentrations of 0.61 ± 0.26 ppm and 15.27 ± 14.62 ppm. We replaced the cross-sensitivity peaks with the 10th percentile baseline of the anesthetic gas concentration. This reduced mean and maximum concentrations significantly by 37% (p < 0.001) and 86% (p < 0.001), respectively. CONCLUSION: Photoacoustic gas monitoring is useful to detect lowest anesthetic gases concentrations, but cross-sensitivity caused one third falsely high measured mean gas concentration. One possibility to eliminate these peaks is the recovery time-based baseline approach. Caution should be taken while measuring sevoflurane, since marked cross-sensitivity peaks are to be expected.
Assuntos
Poluentes Ocupacionais do Ar/análise , Anestésicos Inalatórios/análise , Desinfetantes/análise , Monitoramento Ambiental , Exposição Ocupacional/análise , Técnicas Fotoacústicas , 1-Propanol/análise , 2-Propanol/análise , Desflurano/análise , Etanol/análise , Humanos , Isoflurano/análise , Salas Cirúrgicas , Sevoflurano/análiseRESUMO
1-propanol is a primary alcohol extensively used in the pharmaceutical, chemical, and food industries. It has been also found as a contaminant in the atmosphere and is considered a model compound to mimic the behavior and fate of aliphatic alcohols exposed to environmental conditions. In order to understand that role of relevant variables, this paper presents results obtained with a simple experimental set-up to investigate the reactivity of 1-propanol under mild oxidizing conditions. Coupling this system with CE-C4 D allowed the quantification of the carboxylic acids formed. For the described experiments, aqueous solutions of 1-propanol were placed inside a photoreactor and oxidized upon the addition of TiO2 and/or H2 O2 . According to the described results, the addition of H2 O2 (0.1% w/w) was the most significant variable, roughly tripled the amount of carboxylic acids generated and led to the conversion of up to 70% of the initially available 1-propanol (1 mmol/L). More importantly, the reaction yielded the formation (within 10 min) of propionate (50 µmol/L), acetate (400 µmol/L), formate (50 µmol/L), and malonate (200 µmol/L). The latter is critically important because it represents the first example of the photochemical oxidation of both terminal carbons of the C3 -chain of 1-propanol under mild conditions, and opens new avenues for the production of this important chemical building block.
Assuntos
1-Propanol , Peróxido de Hidrogênio , Fotólise , 1-Propanol/análise , 1-Propanol/química , 1-Propanol/efeitos da radiação , Condutividade Elétrica , Eletroforese Capilar , Malonatos/análise , Malonatos/química , Oxirredução , Fotólise/efeitos dos fármacos , Fotólise/efeitos da radiação , Raios UltravioletaRESUMO
The performance of two vineyard strains, Saccharomyces cerevisiae SacPK7 and Starmerella bacillaris StbPK9, was evaluated in laboratory and pilot scale fermentations of Cretan grape must under the following inoculation schemes: single inoculation of SacPK7 (IS), simultaneous inoculation of StbPK9 and SacPK7 (SM), and sequential inoculation of StbPK9 followed by SacPK7 (SQ). Un-inoculated (spontaneous) fermentations (SP) and fermentations inoculated with control S. cerevisiae strains (CS) were also conducted as reference. Star. bacillaris not only did not restrict but also slightly promoted the growth of S. cerevisiae when the two strains were co-inoculated at equal quantities. On the contrary, the SQ inoculation scheme conferred a competitive advantage to Star. bacillaris over S. cerevisiae, which maximum population was reduced, while increased levels of Star. bacillaris were recorded. The fermentation kinetics were also affected, accordingly. The completion of fermentation was faster in SM, IS and CS ferments than in SQ and SP. Ethanol accumulation had a predominant role in the early death of Star. bacillaris, since its growth was similarly arrested irrespective of the dominating yeast species, the magnitude of yeast population or the availability of energy sources. Interestingly, the inoculation scheme applied significantly affected the chemical profiles of the resulting wines. SQ produced the most divergent chemical profile in sterile must, with glycerol, acetic acid, acetaldehyde, residual glucose, malic acid, ethyl acetate and higher alcohols being the key compounds affected by the prolonged activity of StbPK9. In pilot scale ferments, the indigenous S. cerevisiae produced twice as high levels of esters and higher alcohols compared to the commercial starter. Star. bacillaris further increased the levels of ethyl esters in the respective ferments. The use of a mixed S. cerevisiae/Star. bacillaris starter culture instead of S. cerevisiae alone enhanced the chemical complexity of Cretan local wine. The magnitude of differentiation was even higher when the addition of Star. bacillaris preceded that of S. cerevisiae. The highest divergence in analytical profiles was recorded between wines produced by native strain combinations and commercial S. cerevisiae. Present results show that the use of indigenous yeast formulations provides significant diversification to local wines, in line with the microbial terroir concept and recent observations that indigenous yeast strains may confer regional characters to wines.
Assuntos
Saccharomyces cerevisiae/metabolismo , Saccharomycetales/metabolismo , Vinho/análise , 1-Propanol/análise , Acetaldeído/análise , Acetatos/análise , Ácido Acético/análise , Butanóis/análise , Etanol/análise , Fermentação , Manipulação de Alimentos , Frutose/análise , Glucose/análise , Malatos/análise , Metanol/análise , Projetos Piloto , Vitis/química , Vitis/microbiologia , Compostos Orgânicos Voláteis/análiseRESUMO
The objective of the present study was the development and metrological attestation of the method for the determination of concentrations of low-molecular weight (C1-C4) alcohols and acetone in the biological materials, such as urine and blood including partially dehydrated blood. The method is based on the chromatographic analysis of the equilibrium vapour phase with the use of the static headspace autosampler. The calculations were carried out making use of the results obtained with the application of propanol-1 as the internal standard. In order to enhance the reliability of the identification of the analytes in the complex blood matrix, the two-channel configuration was employed that consisted of a single evaporator, passive flow division, two capillary columns of different polarity, and two flame ionization detectors. The proposed technique provided for the first time the unique possibility to perform the quantitative measurement of the internal standard in the starting specimen before the main analysis. The validated procedure for the quantitative determination of the alcohol concentration of blood samples with the reduced water content has been described. The present study made it possible to collect the total amount of relevant statistical data necessary to calculate the metrological characteristics of the method in question. The method was certified based at D.I. Mendeleev All-Russian Research Institute of Metrology under No 754/242-(01.00250)-2016.
Assuntos
Acetona , Concentração Alcoólica no Sangue , Cromatografia Gasosa/métodos , Etanol , Urinálise/métodos , 1-Propanol/análise , 1-Propanol/química , Acetona/análise , Acetona/química , Etanol/análise , Etanol/química , Toxicologia Forense/métodos , Humanos , Peso Molecular , Reprodutibilidade dos TestesRESUMO
Organic pollutants such as solvents or petroleum products are widespread contaminants in soil and groundwater systems. In-situ bioremediation is a commonly used remediation technology to clean up the subsurface to eliminate the risks of toxic substances to reach potential receptors in surface waters or drinking water wells. This study discusses the development of a subsurface model to analyse the performance of an actively operating field-scale enhanced bioremediation scheme. The study site was affected by a mixed toluene, dihydromyrcenol (DHM), methanol, and i-propanol plume. A high-resolution, time-series of data was used to constrain the model development and calibration. The analysis shows that the observed failure of the treatment system is linked to an inefficient oxygen injection pattern. Moreover, the model simulations also suggest that additional contaminant spillages have occurred in 2012. Those additional spillages and their associated additional oxygen demand resulted in a significant increase in contaminant fluxes that remained untreated. The study emphasises the important role that reactive transport modelling can play in data analyses and for enhancing remediation efficiency.
Assuntos
1-Propanol/análise , Metanol/análise , Monoterpenos/análise , Octanóis/análise , Tolueno/análise , Poluentes Químicos da Água/análise , Biodegradação Ambiental , França , Água Subterrânea/química , Modelos Teóricos , Petróleo , Solo/química , Poluentes do Solo/análiseRESUMO
Ethanol is the most widely used and abused drug. While blood is the preferred specimen for analysis, tissue specimens such as brain serve as alternative specimens for alcohol analysis in post-mortem cases where blood is unavailable or contaminated. A method was developed using headspace gas chromatography with flame ionization detection (HS-GC-FID) for the detection and quantification of ethanol, acetone, isopropanol, methanol and n-propanol in brain tissue specimens. Unfixed volatile-free brain tissue specimens were obtained from the Department of Pathology at Virginia Commonwealth University. Calibrators and controls were prepared from 4-fold diluted homogenates of these brain tissue specimens, and were analyzed using t-butanol as the internal standard. The chromatographic separation was performed with a Restek BAC2 column. A linear calibration was generated for all analytes (mean r2 > 0.9992) with the limits of detection and quantification of 100-110 mg/kg. Matrix effect from the brain tissue was determined by comparing the slopes of matrix prepared calibration curves with those of aqueous calibration curves; no significant differences were observed for ethanol, acetone, isopropanol, methanol and n-propanol. The bias and the CVs for all volatile controls were ≤10%. The method was also evaluated for carryover, selectivity, interferences, bench-top stability and freeze-thaw stability. The HS-GC-FID method was determined to be reliable and robust for the analysis of ethanol, acetone, isopropanol, methanol and n-propanol concentrations in brain tissue, effectively expanding the specimen options for post-mortem alcohol analysis.
Assuntos
Intoxicação Alcoólica/diagnóstico , Química Encefálica , Cromatografia Gasosa , Etanol/análise , Ionização de Chama , 1-Propanol/análise , 2-Propanol/análise , Acetona/análise , Calibragem , Diagnóstico , Humanos , Limite de Detecção , Modelos Lineares , Metanol/análise , Reprodutibilidade dos Testes , Manejo de EspécimesRESUMO
Ensiling conditions strongly influence fermentation characteristics, yeast count, and aerobic stability. Numerous volatile organic compounds including esters are produced, which may negatively affect feed intake and animal performance and air quality. In addition to a farm survey, 3 laboratory experiments were carried out to study the effects of air (by delayed sealing or by air infiltration during anaerobic storage), temperature (20 and 35°C), and various types of additives [blends of either sodium benzoate and sodium propionate (SBSP) or of sodium benzoate and potassium sorbate (SBPS); buffered mixture of formic and propionic acids (FAPA); homofermentative inoculant (LAB)]. After additive treatment, chopped whole corn plants were packed into 1.5-L glass jars and stored for several months. For treatments with air infiltration, glass jars with holes in the lid and body were used. The farm survey in 2009 revealed large variation in lactate, acetate, ethanol, n-propanol, and 1,2-propanediol concentrations. Whereas ethyl esters were detected in all silages, the mean ethyl lactate concentrations were higher than those for ethyl acetate (474 vs. 38mg/kg of dry matter). In the ensiling experiments, few unequivocal effects of the tested factors on the analyzed parameters were observed due to many interactions. Delayed ensiling without additives decreased lactic acid production but, in one trial, increased acetic acid and had no effect on ethanol. The effect of delayed sealing on yeast counts and aerobic stability differed widely among experiments. Air infiltration during fermentation tested in one trial did not alter lactic acid production, but resulted in more acetic acid in delayed and more ethanol than in promptly sealed untreated silages. Greater ethanol production was associated with increased yeast numbers. Storage at high temperature resulted in lower lactic acid and n-propanol, and a trend toward reduced ethanol production was observed. The additive FAPA consistently caused increased ethanol and reduced n-propanol levels with no effect on yeast counts and aerobic stability. When the additives SBSP and SBPS decreased n-propanol and ethanol, reduced yeast counts were also found. Ethyl ester formation was strongly correlated with those of ethanol and to a lesser degree with those of the respective acid.
Assuntos
Ração Animal/análise , Silagem/análise , Compostos Orgânicos Voláteis/análise , Leveduras/metabolismo , Zea mays/química , 1-Propanol/análise , Acetatos/análise , Ração Animal/microbiologia , Animais , Bovinos , Dieta/veterinária , Etanol/análise , Fermentação , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Modelos Lineares , Propionatos/análise , Propilenoglicol/análise , Silagem/microbiologia , Benzoato de Sódio/análise , Ácido Sórbico/análise , Temperatura , Zea mays/microbiologiaRESUMO
A fatality of an inpatient ingesting a disinfectant containing ethanol, propan-1-ol, and propan-2-ol is reported. The alleged survival time was about 1 h. Major findings at autopsy were an extended hemorrhagic lung edema, an edematous brain, and shock kidneys. Concentrations of alcohols and acetone, a major metabolite of propan-2-ol, were determined from body fluids (blood from the heart and the femoral vein, urine, gastric contents) and tissues (brain, muscle, liver, kidneys, lungs) by headspace/gas chromatography using 2-methylpropan-2-ol as the internal standard. All samples investigated were positive for propan-1-ol, propan-2-ol, ethanol, and acetone except stomach contents, where acetone was not detectable. The low concentration of acetone compared to propan-2-ol likely supports the short survival time. The concentration ratios estimated from the results are in accordance with the physico-chemical properties of the particular alcohols, their different affinities towards alcohol dehydrogenase as well as their interdependence during biotransformation. Autopsy did not reveal the cause of death. According to the few published data, blood concentrations of 1.44 and 1.70 mg/g of propan-2-ol and propan-1-ol, respectively, are considered sufficient to have caused the death. This case also points to the need to restrict access to antiseptic solutions containing alcohols in wards with patients at risk.
Assuntos
1-Propanol/intoxicação , 2-Propanol/intoxicação , Desinfetantes/química , Desinfetantes/intoxicação , 1-Propanol/análise , 2-Propanol/análise , Acetona/análise , Transtorno da Personalidade Borderline/psicologia , Química Encefálica , Edema Encefálico/patologia , Etanol/análise , Etanol/intoxicação , Feminino , Conteúdo Gastrointestinal/química , Humanos , Rim/química , Rim/patologia , Fígado/química , Pulmão/química , Músculo Esquelético/química , Edema Pulmonar/patologia , Adulto JovemRESUMO
The aim of the present study was to characterize the volatile metabolites produced by genotypically diverse strains of the Stenotrophomonas genus in order to evaluate their potential as biomarkers of lung infection by non-invasive breath analysis. Volatile organic compounds (VOCs) emitted from 15 clinical and five environmental strains belonging to different genogroups of Stenotrophomonas maltophilia (n = 18) and Stenotrophomonas rhizophila (n = 2) cultured in Mueller-Hinton Broth (MHB) liquid media were analysed by gas chromatography mass spectrometry (GC-MS) and selected ion flow tube mass spectrometry (SIFT-MS). Several VOCs were detected in high concentration, including ammonia, propanol, dimethyl disulphide propanol and dimethyl disulphide. The GC-MS measurements showed that all 15 clinical strains produced similar headspace VOCs compositions, and SIFT-MS quantification showed that the rates of production of the VOCs by the genotypically distinct strains were very similar. All in vitro cultures of both the Stenotrophomonas species were characterised by efficient production of two isomers of methyl butanol, which can be described by known biochemical pathways and which is absent in other pathogens, including Pseudomonas aeruginosa. These in-vitro data indicate that methyl butanol isomers may be exhaled breath biomarkers of S. maltophilia lung infection in patients with cystic fibrosis.
Assuntos
Fibrose Cística/complicações , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções Respiratórias/diagnóstico , Stenotrophomonas/metabolismo , Compostos Orgânicos Voláteis/metabolismo , 1-Propanol/análise , 1-Propanol/metabolismo , Amônia/análise , Amônia/metabolismo , Biomarcadores/análise , Testes Respiratórios/métodos , Dissulfetos/análise , Dissulfetos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Genótipo , Infecções por Bactérias Gram-Negativas/complicações , Infecções por Bactérias Gram-Negativas/metabolismo , Humanos , Técnicas In Vitro , Espectrometria de Massas/métodos , Infecções Respiratórias/complicações , Infecções Respiratórias/metabolismo , Stenotrophomonas/química , Compostos Orgânicos Voláteis/análiseRESUMO
A comparative study on the sensing characteristics of nanostructured zinc ferrite to three primary alcohols viz. methanol, ethanol and propanol has been carried out. The zinc ferrite has been prepared by a combustion method and characterized by XRD, FTIR, AFM and SEM. Impedance studies in the alcohol concentration range varying from 100 to 1000 ppm show definite variations in response to both the nature of the alcohol and its concentration. The nanostructured zinc ferrite shows the highest sensor response to methanol and least to propanol. Equivalent circuit modelling and calibration have been made for all the three alcohol sensors. The material shows a better selectivity to the alcohols compared to formaldehyde, ammonia and acetone vapours.
Assuntos
Álcoois/análise , Compostos Férricos/química , Zinco/química , 1-Propanol/análise , Acetona/análise , Amônia/análise , Calibragem , Eletroquímica/métodos , Etanol/análise , Formaldeído/análise , Gases/análise , Metanol/análise , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Volatilização , Difração de Raios XRESUMO
To evaluate the current practice of corn silage management in China, samples of bunker-made silage were collected from 14 farms within a 500-km radius of Beijing for the analysis of fermentation products and bacterial communities. Mean values for dry matter (DM) content were as low as 250 g/kg in both corn stover (St) and whole crop corn (Wc) silages, and pH values averaged 4.48 and 3.73, respectively. Only three of the 14 silages exhibited a lactic-to-acetic acid ratio > 1.0, indicating that the presence of acetic acid was predominant in fermentation. Although 1,2-propanediol content was marginal in most cases (< 5.0 g/kg dry matter (DM)), two Wc silages had 1,2-propanediol levels > 25 g/kg DM. In contrast, 3 St silages had large amounts (> 10 g/kg DM) of butyric acid, and two of the three butyrate silages also had high concentrations of 1-propanol. Denaturing gradient gel electrophoresis analysis demonstrated that the bacterial community appeared similar in 10 out of the 14 silage samples. Bands indicating Lactobacillus buchneri, L. acetotolerans and Acetobacter pasteurianus were found in both the St and Wc silages, accounting for the high acetic acid content found across silage samples.
Assuntos
Acetobacter/isolamento & purificação , Fermentação , Lactobacillus/isolamento & purificação , Silagem/análise , Silagem/microbiologia , Zea mays/microbiologia , 1-Propanol/análise , Ácido Acético/análise , Ácido Butírico/análise , China , Eletroforese em Gel de Gradiente Desnaturante , Ácido Láctico/análise , Propilenoglicol/análiseRESUMO
Monoglycerides (MGs) can form self-assembled structures in emulsions, which can be used to control volatile release. In this study, initial headspace concentrations (C(initial)), maximum headspace concentrations (C(max)), release rates, and partition coefficients of propanol, diacetyl, hexanal, and limonene were determined in MG structured oil-in-water emulsions using dynamic and static headspace analyses. For all of the volatile compounds, C(initial) values above structured emulsions were significantly lower than those above unstructured emulsions and decreased with increasing MG contents (p < 0.05). However, volatiles had higher release rates in emulsions with higher MG contents. When oil content was reduced from 20 to 10%, C(initial) and C(max) increased for limonene and hexanal and decreased for propanol and diacetyl. When different oils were applied, both C(initial) and C(max) were significantly lower in medium-chain triglyceride emulsions than in soybean oil emulsions (p < 0.05). Static headspace analysis revealed that volatile compounds had significantly lower air-emulsion partition coefficients in the structured emulsions than in unstructured emulsions (p < 0.05). These results indicated that MG structured emulsions can be potentially used as delivery systems to modulate volatile release.
Assuntos
Emulsões/química , Monoglicerídeos/análise , Óleos Voláteis/análise , Óleos Voláteis/química , 1-Propanol/análise , Aldeídos/análise , Varredura Diferencial de Calorimetria , Cicloexenos/análise , Diacetil/análise , Limoneno , Monoglicerídeos/química , Terpenos/análise , Triglicerídeos/análise , Triglicerídeos/química , Água/químicaRESUMO
BACKGROUND: Urine ethyl glucuronide (EtG) is considered as a specific marker of recent ethanol consumption. We describe false-positive DRI(®) EIA EtG enzyme immunoassay results caused by propyl glucuronides in urine after using a propanol-based hand sanitizer. METHODS: EtG screening was done with the DRI(®) EIA EtG assay (Microgenics), using a cut-off of 0.5 mg/L as recommended by the manufacturer and of 0.1 mg/L as demanded by the German Regulations for Reissuing Drivers Licenses. Confirmatory EtG analysis was done with the ClinMass(®) EtG LC-MS/MS testkit (Recipe), extended by the mass transitions 235.1â75.1, 235.1â85.1, and 235.1â113.1 for the detection of the 1- and 2-propyl glucuronides. Self-experiments were done by staff members of our lab (n=7), using 3 mL Sterillium(®) Classic Pure (30 g/100 g 1-propanol and 45 g/100 g 2-propanol) for hand sanitation every quarter of an hour for 8 h according to DIN EN 1500:2011-05 with and without an exhauster and by passive inhalation of the sanitizer vapor. Spot urine samples were taken immediately before and up to 24 h after the first sanitizer use. RESULTS: False-positive immunoassay results of up to 4 mg/L or 2.3 mg/g creatinine were obtained after normal use of the sanitizer and also after passive inhalation of the sanitizer vapor (up to 0.89 mg/L or 0.61 mg/g). Immunoassay results were positive even after 4-fold use of the sanitizer (up to 0.14 mg/L or 0.38 mg/g) and up to 6 h after the last sanitizer contact (maximum 0.63 mg/L and 0.33 mg/g for sanitizer users and 0.25 mg/g after passive inhalation). Spiking of EtG-free urine with 1-propyl glucuronide (Athena Environmental Sciences) between 0.05 and 10 mg/L clearly demonstrated a cross reaction of the immunoassay of approx. 10% as compared to EtG. LC-MS/MS of urines with a positive immunoassay EtG result did not show EtG signals, but distinct signals of 1-propyl glucuronide (n-propyl glucuronide) and 2-propyl glucuronide (iso-propyl glucuronide). An exhauster effectively prevented the inhalation of the sanitizer vapor, the formation of propyl glucuronides and thus false-positive DRI(®) EIA EtG screening results, proving that propyl alcohols are almost exclusively taken up by respiration. CONCLUSIONS: The widespread use of propanol-containing products such as hand sanitizers may lead to sufficient uptake of propyl alcohols and excretion of significant amounts of propyl glucuronides to yield false-positive DRI(®) EIA EtG screening results. Thus, positive EtG immunoassay results have to be controlled by mass-spectrometry, in clinical cases at least if ethanol intake is denied by the patient.
Assuntos
1-Propanol/análise , Desinfetantes/química , Reações Falso-Positivas , Glucuronatos/urina , Consumo de Bebidas Alcoólicas , Biomarcadores/urina , Cromatografia Líquida , Toxicologia Forense , Desinfecção das Mãos , Humanos , Imunoensaio , Espectrometria de MassasRESUMO
A sensitive and stereospecific liquid chromatography-tandem mass spectrometry method for the quantitative determination of TWo8 enantiomers ((2RS)-1-(7-methoxy-1H-indol-4-yloxy)-3-(2-(2-methoxyphenoxy)ethylamino)-propan-2-ol) was developed and validated in rat serum and some tissues. Racemic TWo8 is a new chemical entity, and it has been shown to possess pharmacological activity in vivo. The assay involved the diastereomeric derivatization of racemic TWo8 with 2,3,4,6-tetra-O-acetyl-beta-glucopyranosyl isothiocyanate. The TWo8 diastereoisomers quantification was performed on a triple quadrupole mass spectrometer employing an electrospray ionization technique. The precursor to the product ion transition for TWo8 derivatives and for the internal standard (carbamazepine) was m/z 776.4 â 387.2 and 237.4 â 194.4, respectively. The assay was validated with a linear range of 10-2000 ng/ml of racemic TWo8. The inter-day precisions for (-)-(S)-TWo8 and (+)-(R)-TWo8 were 2.1% to 14.9% and 1.3% to 14.8%, respectively. The inter-day accuracy for (-)-(S)-TWo8 and (+)-(R)-TWo8 was within 86% to 114% and 91% to 114%, respectively. A pilot pharmacokinetic study of this new ß-adrenolytic compound has shown that (-)-(S)-TWo8 is eliminated faster than its antipode. The terminal half-lives of (-)-(S)-TWo8 and (+)-(R)-TWo8 were 3.2 and 3.9 h, respectively. The compound distribution into different organs, evaluated in tissue homogenate samples following TWo8 intravenous administration, showed an enantioselective penetration of TWo8 enantiomers in the liver (p < 0.03), in the kidney (p < 0.001), and in the lungs (p < 0.05). The developed method using liquid chromatography-tandem mass spectrometry method with electrospray ionization could be employed for quantitative determination of compounds with similar structure.
Assuntos
1-Propanol/análise , 1-Propanol/farmacocinética , Antagonistas Adrenérgicos/análise , Antagonistas Adrenérgicos/farmacocinética , Indóis/análise , Indóis/farmacocinética , Propanolaminas/análise , Propanolaminas/farmacocinética , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , 1-Propanol/química , 1-Propanol/isolamento & purificação , Antagonistas Adrenérgicos/química , Antagonistas Adrenérgicos/isolamento & purificação , Animais , Calibragem , Cromatografia Líquida de Alta Pressão , Indóis/química , Indóis/isolamento & purificação , Isotiocianatos/química , Limite de Detecção , Masculino , Propanolaminas/química , Propanolaminas/isolamento & purificação , Ratos , Ratos Wistar , Estereoisomerismo , Especificidade por Substrato , Distribuição TecidualRESUMO
An 88-year-old woman committed suicide by drinking a toxic amount of highly concentrated alcohol and setting two rooms of her flat on fire. As there was not enough oxygen, the fire went out, however. At autopsy, no thermal lesions were found on the body, but soot depositions in the airways and a COHb value of 14% pointed to the inhalation of fire fumes. The ethanol concentration in femoral blood was 6.62 per mille. The gastric mucosa was fixed by the ingested alcohol and showed hardly any autolytic changes despite a post-mortem interval of five days. Congener analysis of the gastric contents and the femoral blood indicated the uptake of a fruit distillate or its foreshot.