Sol-gel-based SPME fiber as a reliable sampling technique for studying biogenic volatile organic compounds released from Clostridium tetani.

Science.gov (United States)

Ghader, Masoud; Shokoufi, Nader; Es-Haghi, Ali; Kargosha, Kazem

2017-11-01

A novel and efficient headspace solid-phase microextraction (HS-SPME) method, followed by gas chromatography mass spectrometry (GC-MS), was developed to study volatile organic compounds (VOCs) emerging from microorganisms. Two homemade SPME fibers, a semi-polar poly (dimethylsiloxane) (PDMS) fiber, and a polar polyethylene glycol (PEG) fiber, along with two commercial fibers (PDMS and PDMS/DVB) were used to collect VOCs emerging from Clostridium tetani which was cultured in different media. The adsorbed VOCs were desorbed and identified, in vitro, using GC-MS. The adsorption efficiency was improved by optimizing the time duration of adsorption and desorption. About 50 components were identified by the proposed method. The main detected compounds appeared to be sulfur containing compounds such as butanethioic acid S-methyl ester, dimethyl trisulfide, and dimethyl tetrasulfide. These volatile sulfur containing compounds are derived from amino acids containing the sulfur element, which probably coexist in the mentioned bacterium or are added to the culture media. The developed HS-SPME-GC-MS method allowed the determination of the chemical fingerprint of Clostridium tetani volatile constituents, and thus provides a new, simple, and reliable tool for studying the growth of microorganisms. Graphical abstract Investigation of biogenic VOCs released from Clostridium tetani using SPME-GC-MS.

Sulfur volatiles in guava (Psidium guajava L.) leaves: possible defense mechanism.

Science.gov (United States)

Rouseff, Russell L; Onagbola, Ebenezer O; Smoot, John M; Stelinski, Lukasz L

2008-10-08

Volatiles from crushed and intact guava leaves (Psidium guajava L.) were collected using static headspace SPME and determined using GC-PFPD, pulsed flame photometric detection, and GC-MS. Leaf volatiles from four common citrus culitvars were examined similarly to determine the potential component(s) responsible for guava's protective effect against the Asian citrus psyllid (Diaphorina citri Kuwayama), which is the insect vector of Huanglongbing (HLB) or citrus greening disease. Seven sulfur volatiles were detected: hydrogen sulfide, sulfur dioxide, methanethiol, dimethyl sulfide (DMS), dimethyl disulfide (DMDS), methional, and dimethyl trisulfide (DMTS). Identifications were based on matching linear retention index values on ZB-5, DB-Wax, and PLOT columns and MS spectra in the case of DMDS and DMS. DMDS is an insect toxic, defensive volatile produced only by wounded guava but not citrus leaves and, thus, may be the component responsible for the protective effect of guava against the HLB vector. DMDS is formed immediately after crushing, becoming the major headspace volatile within 10 min. Forty-seven additional leaf volatiles were identified from LRI and MS data in the crushed guava leaf headspace.

Nonvolatile, semivolatile, or volatile: redefining volatile for volatile organic compounds.

Science.gov (United States)

Võ, Uyên-Uyén T; Morris, Michael P

2014-06-01

Although widely used in air quality regulatory frameworks, the term "volatile organic compound" (VOC) is poorly defined. Numerous standardized tests are currently used in regulations to determine VOC content (and thus volatility), but in many cases the tests do not agree with each other, nor do they always accurately represent actual evaporation rates under ambient conditions. The parameters (time, temperature, reference material, column polarity, etc.) used in the definitions and the associated test methods were created without a significant evaluation of volatilization characteristics in real world settings. Not only do these differences lead to varying VOC content results, but occasionally they conflict with one another. An ambient evaporation study of selected compounds and a few formulated products was conducted and the results were compared to several current VOC test methodologies: SCAQMD Method 313 (M313), ASTM Standard Test Method E 1868-10 (E1868), and US. EPA Reference Method 24 (M24). The ambient evaporation study showed a definite distinction between nonvolatile, semivolatile, and volatile compounds. Some low vapor pressure (LVP) solvents, currently considered exempt as VOCs by some methods, volatilize at ambient conditions nearly as rapidly as the traditional high-volatility solvents they are meant to replace. Conversely, bio-based and heavy hydrocarbons did not readily volatilize, though they often are calculated as VOCs in some traditional test methods. The study suggests that regulatory standards should be reevaluated to more accurately reflect real-world emission from the use of VOC containing products. The definition of VOC in current test methods may lead to regulations that exclude otherwise viable alternatives or allow substitutions of chemicals that may limit the environmental benefits sought in the regulation. A study was conducted to examine volatility of several compounds and a few formulated products under several current VOC test

Production of volatile and sulfur compounds by ten Saccharomyces cerevisiae strains inoculated in Trebbiano must

Directory of Open Access Journals (Sweden)

Francesca ePatrignani

2016-03-01

Full Text Available In wines, the presence of sulphur compounds is the resulting of several contributions among which yeast metabolism. The characterization of the starter Saccharomyces cerevisiae needs to be performed also taking into account this ability even if evaluated together with the overall metabolic profile. In this perspective, principal aim of this experimental research was the evaluation of the volatile profiles, throughout GC/MS technique coupled with solid phase micro extraction, of wines obtained throughout the fermentation of 10 strains of Saccharomyces cerevisiae. In addition, the production of sulphur compounds was further evaluated by using a gas-chromatograph coupled with a Flame Photometric Detector. Specifically, the ten strains were inoculated in Trebbiano musts and the fermentations were monitored for 19 days. In the produced wines, volatile and sulphur compounds as well as amino acid concentrations were investigated. Also the physico-chemical characteristics of the wines and their electronic nose profiles were evaluated.

The effects of diet and breed on the volatile compounds of cooked lamb.

Science.gov (United States)

Elmore, J S; Mottram, D S; Enser, M; Wood, J D

2000-06-01

The effect of varying the n-3 polyunsaturated fatty acid (PUFA) composition of lamb muscle on the formation of aroma volatiles during cooking has been examined. The meat was obtained from four groups of Suffolk and Soay lambs fed different supplementary fats: a palm-oil based control; bruised whole linseed, which increased muscle levels of α-linolenic acid (C18:3 n-3); fish oil, which increased eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3); and equal quantities of linseed and fish oil (fat basis). Higher quantities of lipid oxidation products were found in the aroma volatiles of lamb muscle from animals fed fish oil, compared to the control. In particular, unsaturated aldehydes, unsaturated hydrocarbons and alkylfurans increased up to fourfold. These compounds derived from the autoxidation of PUFAs during cooking. Although some of these volatiles were increased in meat from animals fed the linseed supplement, the effect was not as great as with the fish oil fed lambs. Levels of volatiles derived from the Maillard reaction, such as pyrazines and sulfur compounds, were up to four times higher in Soays than Suffolks.

Effects of soy sauce and packaging method on volatile compounds and lipid oxidation of cooked irradiated beef patties

Science.gov (United States)

Kim, Hyun-Wook; Lee, Soo-Yeon; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Ham, Yun-Kyung; Lee, Choong-Hee; Choi, Yun-Sang; Lee, Ju-Woon; Kim, Cheon-Jei

2014-10-01

The objective of this study is to determine the effect of soy sauce on volatile compounds and lipid oxidation of cooked irradiated beef patties. Sulfur-containing volatile components, which are produced by irradiation, were not found in all treatments. Volatile components derived from soy sauce, such as 3-hydroxy-2-butanone, acetic acid, 3-methyl-1-butanol and 2-methyl-1-butanol, were detected in beef patties containing soy sauce regardless of irradiation and packaging method. Volatile aldehydes, including hexanal, significantly decreased the irradiated beef patty prepared with soy sauce compared to those of irradiated beef patty made with NaCl at 1 day and 5 days after irradiation. In addition, combined use of vacuum packaging and soy sauce treatments could inhibit the formation of volatile compounds and 2-thiobarbituric acid reactive substances during chilled storage. Therefore, the use of soy sauce in cooked and irradiated beef could reduce the production of volatile components associated with the irradiation-induced off-flavor and lipid oxidation.

Emission characteristics of nitrogen- and sulfur-containing odorous compounds during different sewage sludge chemical conditioning processes

Energy Technology Data Exchange (ETDEWEB)

Liu, Huan [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Luo, Guang-Qian; Hu, Hong-Yun [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang, Qiang; Yang, Jia-Kuan [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yao, Hong, E-mail: hyao@hust.edu.cn [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer NH{sub 3}, SO{sub 2}, H{sub 2}S and COS are emitted during different sludge conditioning processes. Black-Right-Pointing-Pointer H{sub 2}S and SO{sub 2} generation increase in the acidic environment created by H{sub 2}SO{sub 4}. Black-Right-Pointing-Pointer Fenton peroxidation facilitates the formation of COS. Black-Right-Pointing-Pointer CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. Black-Right-Pointing-Pointer CaO leads to the conversion of free ammonia or protonated amine to volatile NH{sub 3}. - Abstract: Chemical conditioners are often used to enhance sewage sludge dewaterability through altering sludge properties and flocs structure, both affect odorous compounds emissions not only during sludge conditioning but also in subsequent sludge disposal. This study was to investigate emission characteristics of ammonia (NH{sub 3}), sulfur dioxide (SO{sub 2}), hydrogen sulfide (H{sub 2}S) and carbonyl sulfide (COS) generated from sewage sludge conditioned by three representative conditioners, i.e., organic polymers, iron salts and skeleton builders, F-S (Fenton's reagent and skeleton builders) composite conditioner. The results demonstrate that polyacrylamide (PAM) has an insignificant effect on emission characteristics of nitrogen- and sulfur-containing odorous compounds, because the properties, sulfur and nitrogen speciations are similar in PAM-conditioned sludge and raw sludge (RS). Significant increases of SO{sub 2} and H{sub 2}S emissions in the H{sub 2}SO{sub 4} conditioning process were observed due to the accelerated decomposition of sulfur-containing amino acids in acidic environment. Fenton peroxidation facilitates the formation of COS. CaO can reduce sulfur-containing gases emission via generation of calcium sulfate. However, under strong alkaline conditions, free ammonia or protonated amine in sludge can be easily converted to volatile ammonia, resulting in a significant

Behaviour of organic sulfur compounds in HPLC

International Nuclear Information System (INIS)

Freyholdt, T.

1982-01-01

The retention behaviour of organic sulfur compounds in the reverse-bonded-phase chromatography is characterized by determining the retention indices according to Kovats. The results of these studies show that the solubility of organic compounds in the eluting agent and the molar sorption surfaces of the solutes are the main factors determining the retention behaviour. Knowledge of the retention indices of above-mentioned compounds allows a quick interpretation of chromatograms obtained through a product analysis of γ-irradiated aqueous solutions of organic sulfur compounds. Dithia compounds of the type CH 3 -S-(CH 2 )sub(n)-S-Ch 3 (1 1. 2,4-Dithiapentane (n = 1) however will yield primarily monothio-S-methyl formate as a stable end product. The formation of oxygenic reaction products proceeds via sulfur-centred radical kations. Spin trapping experiments with nitroxyl radicals show that it is possible to trap radiation-chemically produced radicals of sulfurous substrates, but the thus obtained adducts with half-life periods of 4-5 min. cannot be identified by means of NMR, IR or mass spectroscopy. (orig.) [de

Comparative Evaluation of Sulfur Compounds Contents and Antiobesity Properties of Allium hookeri Prepared by Different Drying Methods

Directory of Open Access Journals (Sweden)

Min Hye Yang

2017-01-01

Full Text Available Despite the nutritional and medicinal values of Allium hookeri, its unique flavor (onion or garlic taste and smell coming from sulfur containing compounds limits its usage as functional food. For comparative study, A. hookeri roots were prepared under two different drying conditions, namely, low-temperature drying that minimizes the volatilization of sulfur components and hot-air drying that minimizes the garlic odor and spicy taste of A. hookeri. In GC/MS olfactory system, the odorous chemicals and organosulfur compounds such as diallyl trisulfide, dimethyl trisulfide, and dipropyl trisulfide were significantly decreased in hot-air drying compared to low-temperature drying. The spiciness and saltiness taste were noticeably reduced, while sourness, sweetness, and umami taste were significantly increased in hot-air dried A. hookeri according to electronic tongue. Although the content of volatile sulfur components was present at lower level, the administration of hot-air dried A. hookeri extract (100 mg/kg p.o. apparently prevented the body weight gain and improved insulin resistance in C57BL/6J obese mice receiving high fat diet. Results suggested that the hot-air dried A. hookeri possessing better taste and odor might be available as functional crop and bioactive diet supplement for the prevention and/or treatment of obesity.

Effect of sequential fermentations and grape cultivars on volatile compounds and sensory profiles of Danish wines

DEFF Research Database (Denmark)

Liu, Jing; Arneborg, Nils; Toldam-Andersen, Torben

2017-01-01

BACKGROUND: There has been an increasing interest in the use of selected non-Saccharomyces yeasts in co-culture with Saccharomyces cerevisiae. In this work, three non-Saccharomyces yeast strains (Metschnikowia viticola, Metschnikowia fructicola and Hanseniaspora uvarum) indigenously isolated...... in Denmark were used in sequential fermentations with S. cerevisiae on three cool-climate grape cultivars, Bolero, Rondo and Regent. During the fermentations, the yeast growth was determined as well as key oenological parameters, volatile compounds and sensory properties of finished rosé wines. RESULTS......: The different non-Saccharomyces strains and cool-climate grape cultivars produced wines with a distinctive aromatic profile. A total of 67 volatile compounds were identified, including 43 esters, 14 alcohols, five acids, two ketones, a C13-norisoprenoid, a lactone and a sulfur compound. The use of M. viticola...

Multiple-heteroatom-containing sulfur compounds in a high sulfur coal

International Nuclear Information System (INIS)

Winans, R.E.; Neill, P.H.

1990-01-01

Flash vacuum pyrolysis of a high sulfur coal has been combined with high resolution mass spectrometry yielding information on aromatic sulfur compounds containing an additional heteroatom. Sulfur emission from coal utilization is a critical problem and in order to devise efficient methods for removing organic sulfur, it is important to know what types of molecules contain sulfur. A high sulfur Illinois No. 6 bituminous coal (Argonne Premium Coal Sample No. 3) was pyrolyzed on a platinum grid using a quartz probe inserted into a modified all glass heated inlet system and the products characterized by high resolution mass spectrometry (HRMS). A significant number of products were observed which contained both sulfur and an additional heteroatom. In some cases two additional heteroatoms were observed. These results are compared to those found in coal extracts and liquefaction products

Use of zeolites for the removal of volatile sulfur compounds from industrial waste gases and from natural gases

Energy Technology Data Exchange (ETDEWEB)

Dudzik,; Z,; Bilska, M

1974-12-01

The use of zeolites for the removal of sulfur dioxide from industrial waste gases and for the removal of hydrogen sulfide and volatile mercaptans from the natural gas or synthetic gas manufactured from coal is discussed. The effectiveness and cost of zeolite methods are superior to that of other methods. The best sorption properties with respect to sulfur dioxide are observed in faujasites and erionites. The molecular sieve 13X (a sodium form of low-silicon faujasite) is the most effective sorbent of hydrogen sulfide, produced commercially on a large scale. This zeolite is also a very effective catalyst for simultaneous oxygenation of hydrogen sulfide. The reaction with oxygen can begin at temperatures as low as -80/sup 0/C. The effectiveness of zeolite reactors is enhanced by the presence of oxygen in the gas being purified, and is hindered by the presence of water or water vapor. The extraordinary catalytic activity of sodium faujasites is due to free donors, and sulfur and oxygen ion donors at their surface. A zeolite reactor is also economical.

Microbiological disproportionation of inorganic sulfur compounds

DEFF Research Database (Denmark)

Finster, Kai

2008-01-01

The disproportionation of inorganic sulfur intermediates at moderate temperatures (0-80 °C) is a microbiologically catalyzed chemolithotrophic process in which compounds like elemental sulfur, thiosulfate, and sulfite serve as both electron donor and acceptor, and generate hydrogen sulfide and su...

Improving rubber concrete by waste organic sulfur compounds.

Science.gov (United States)

Chou, Liang-Hisng; Lin, Chun-Nan; Lu, Chun-Ku; Lee, Cheng-Haw; Lee, Maw-Tien

2010-01-01

In this study, the use of crumb tyres as additives to concrete was investigated. For some time, researchers have been studying the physical properties of concrete to determine why the inclusion of rubber particles causes the concrete to degrade. Several methods have been developed to improve the bonding between rubber particles and cement hydration products (C-S-H) with the hope of creating a product with an improvement in mechanical strength. In this study, the crumb tyres were treated with waste organic sulfur compounds from a petroleum refining factory in order to modify their surface properties. Organic sulfur compounds with amphiphilic properties can enhance the hydrophilic properties of the rubber and increase the intermolecular interaction forces between rubber and C-S-H. In the present study, a colloid probe of C-S-H was prepared to measure these intermolecular interaction forces by utilizing an atomic force microscope. Experimental results showed that rubber particles treated with waste organic sulfur compounds became more hydrophilic. In addition, the intermolecular interaction forces increased with the adsorption of waste organic sulfur compounds on the surface of the rubber particles. The compressive, tensile and flexural strengths of concrete samples that included rubber particles treated with organic sulfur compound also increased significantly.

Characterisation of selected volatile organic compounds in ...

African Journals Online (AJOL)

GCMS), was used to identify volatile compounds at three different temperatures. Fifty volatile compounds, inclusive of 14 acids, 14 alcohols, and 22 esters were identified and quantified in the two brands of indigenous banana beer samples. Only 12 ...

Volatile and non-volatile/semi-volatile compounds and in vitro bioactive properties of Chilean Ulmo (Eucryphia cordifolia Cav.) honey.

Science.gov (United States)

Acevedo, Francisca; Torres, Paulina; Oomah, B Dave; de Alencar, Severino Matias; Massarioli, Adna Prado; Martín-Venegas, Raquel; Albarral-Ávila, Vicenta; Burgos-Díaz, César; Ferrer, Ruth; Rubilar, Mónica

2017-04-01

Ulmo honey originating from Eucryphia cordifolia tree, known locally in the Araucania region as the Ulmo tree is a natural product with valuable nutritional and medicinal qualities. It has been used in the Mapuche culture to treat infections. This study aimed to identify the volatile and non-volatile/semi-volatile compounds of Ulmo honey and elucidate its in vitro biological properties by evaluating its antioxidant, antibacterial, antiproliferative and hemolytic properties and cytotoxicity in Caco-2 cells. Headspace volatiles of Ulmo honey were isolated by solid-phase microextraction (SPME); non-volatiles/semi-volatiles were obtained by removing all saccharides with acidified water and the compounds were identified by GC/MS analysis. Ulmo honey volatiles consisted of 50 compounds predominated by 20 flavor components. Two of the volatile compounds, lyrame and anethol have never been reported before as honey compounds. The non-volatile/semi-volatile components of Ulmo honey comprised 27 compounds including 13 benzene derivatives accounting 75% of the total peak area. Ulmo honey exhibited weak antioxidant activity but strong antibacterial activity particularly against gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA), the main strain involved in wounds and skin infections. At concentrations >0.5%, Ulmo honey reduced Caco-2 cell viability, released lactate dehydrogenase (LDH) and increased reactive oxygen species (ROS) production in a dose dependent manner in the presence of foetal bovine serum (FBS). The wide array of volatile and non-volatile/semi-volatile constituents of Ulmo honey rich in benzene derivatives may partly account for its strong antibacterial and antiproliferative properties important for its therapeutic use. Our results indicate that Ulmo honey can potentially inhibit cancer growth at least partly by modulating oxidative stress. Copyright © 2017 Elsevier Ltd. All rights reserved.

Volatiles from roasted byproducts of the poultry-processing industry.

Science.gov (United States)

Wettasinghe, M; Vasanthan, T; Temelli, F; Swallow, K

2000-08-01

Volatiles of roasted chicken breast muscle and byproducts, such as backbones, breastbones, spent bones, and skin, were investigated. Total volatile concentrations ranged from 2030 ppb in the roasted backbones to 4049 ppb in the roasted skin. The major classes of volatile compounds detected in roasted samples were aldehydes (648-1532 ppb) and alcohols (336-1006 ppb). Nitrogen- and/or sulfur-containing compounds were also detected in appreciable quantities (161-706 ppb) in all samples. For all samples, hexanal and 2-methyl-2-buten-1-ol were dominant among the aldehydes and alcohols, respectively. Among the nitrogen- and sulfur-containing compounds, Maillard reaction products, such as tetrahydropyridazines, piperidines, and thiazoles, were the major contributors to the total volatile content in all samples. The composition of volatiles observed in roasted byproducts was markedly different from that of the roasted breast muscle. Therefore, the blending of the byproducts in appropriate proportions or blending of volatile flavor extracts from different byproducts may be necessary to obtain an aroma that mimics roasted chicken aroma.

Biogenic sulfur compounds and the global sulfur cycle

International Nuclear Information System (INIS)

Aneja, V.P.; Aneja, A.P.; Adams, D.F.

1982-01-01

Field measurements of biogenic sulfur compounds shows a great variation in concentrations and emission rates for H 2 S, DMS, CS 2 and COS. Measurements by the chamber method and estimates from micrometeorological sampling are employed to determine the earth-atmosphere flux of these gases. Much of the variation can be attributed to differences of climate and surface conditions, with marshes being a large source of biogenic sulfur (mean contribution 4 x 10 to the 6th ton/year maximum contribution 142 x 10 to the 6th ton/year). Considering that the estimated biogenic contribution needed to balance the global sulfur cycle ranges from 40- 230 x 10 to the 6th tons/year, the mean values are not sufficient to balance this cycle. Further experimental investigations are suggested in order to characterize the biogenic processes adequately

Effects of soy sauce and packaging method on volatile compounds and lipid oxidation of cooked irradiated beef patties

International Nuclear Information System (INIS)

Kim, Hyun-Wook; Lee, Soo-Yeon; Hwang, Ko-Eun; Song, Dong-Heon; Kim, Yong-Jae; Ham, Yun-Kyung; Lee, Choong-Hee; Choi, Yun-Sang; Lee, Ju-Woon; Kim, Cheon-Jei

2014-01-01

The objective of this study is to determine the effect of soy sauce on volatile compounds and lipid oxidation of cooked irradiated beef patties. Sulfur-containing volatile components, which are produced by irradiation, were not found in all treatments. Volatile components derived from soy sauce, such as 3-hydroxy-2-butanone, acetic acid, 3-methyl-1-butanol and 2-methyl-1-butanol, were detected in beef patties containing soy sauce regardless of irradiation and packaging method. Volatile aldehydes, including hexanal, significantly decreased the irradiated beef patty prepared with soy sauce compared to those of irradiated beef patty made with NaCl at 1 day and 5 days after irradiation. In addition, combined use of vacuum packaging and soy sauce treatments could inhibit the formation of volatile compounds and 2-thiobarbituric acid reactive substances during chilled storage. Therefore, the use of soy sauce in cooked and irradiated beef could reduce the production of volatile components associated with the irradiation-induced off-flavor and lipid oxidation. - Highlights: • Soy sauce (SS) could inhibit volatiles cooked irradiated beef patties. • Vacuum packaging and SS treatment is effective to prevent lipid oxidation. • Hexanal content was highly correlated with TBA value of the irradiated beef patties

Surface microlayer enrichment of volatile organic compounds and semi-volatile organic compounds in drinking water source.

Science.gov (United States)

Huang, Zhi; Zhou, Wen; Yu, Ya-juan; Zhang, Ai-qian; Han, Shuo-kui; Wang, Lian-sheng

2004-01-01

Enrichment of volatile organic compounds(VOC) and semi-volatility organic compounds(SVOC) in surface microlayer(SM) of three drinking water sources were studied. The enrichment factor(EFs) were 0.67 to 13.37 and 0.16 to 136, respectively. The results showed some VOC and most SVOC could enrich in SM. Some EFs of SVOC was quite high. Suspension and temperature could affect EFs of SVOC, slim wind and water movement do not destroy enrichment of organic in SM.

Fig volatile compounds--a first comparative study.

Science.gov (United States)

Grison-Pigé, Laure; Hossaert-McKey, Martine; Greeff, Jaco M; Bessière, Jean-Marie

2002-09-01

We analysed the compounds of volatile blends released by receptive figs of twenty Ficus species to attract their specific pollinating wasps. In all, 99 different compounds were identified. The compounds are mainly terpenoids, aliphatic compounds and products from the shikimic acid pathway. In each species blend, there are few major compounds, which are generally common among floral fragrances. Most species blends also include rare compounds, but generally their proportion in the blend is low. A possible basis for species-specificity of Ficus-wasp interactions is discussed in relation to the patterns of volatiles found in this interspecies comparison. Copyright 2002 Elsevier Science Ltd.

Some information needs for air quality modeling. [Environmental effects of sulfur compounds

Energy Technology Data Exchange (ETDEWEB)

Hill, F B

1975-09-01

The following topics were considered at the workshop: perturbation of the natural sulfur cycle by human activity; ecosystem responses to a given environmental dose of sulfur compounds; movement of sulfur compounds within the atmosphere; air quality models; contribution of biogenic sulfur compounds to atmospheric burden of sulfur; production of acid rain from sulfur dioxide; meteorological processes; and rates of oxidation of SO/sub 2/ via direct photo-oxidation, oxidation resulting from photo-induced free radical chemistry, and catalytic oxidation in cloud droplets and on dry particles. (HLW)

The volatile compound BinBase mass spectral database.

Science.gov (United States)

Skogerson, Kirsten; Wohlgemuth, Gert; Barupal, Dinesh K; Fiehn, Oliver

2011-08-04

Volatile compounds comprise diverse chemical groups with wide-ranging sources and functions. These compounds originate from major pathways of secondary metabolism in many organisms and play essential roles in chemical ecology in both plant and animal kingdoms. In past decades, sampling methods and instrumentation for the analysis of complex volatile mixtures have improved; however, design and implementation of database tools to process and store the complex datasets have lagged behind. The volatile compound BinBase (vocBinBase) is an automated peak annotation and database system developed for the analysis of GC-TOF-MS data derived from complex volatile mixtures. The vocBinBase DB is an extension of the previously reported metabolite BinBase software developed to track and identify derivatized metabolites. The BinBase algorithm uses deconvoluted spectra and peak metadata (retention index, unique ion, spectral similarity, peak signal-to-noise ratio, and peak purity) from the Leco ChromaTOF software, and annotates peaks using a multi-tiered filtering system with stringent thresholds. The vocBinBase algorithm assigns the identity of compounds existing in the database. Volatile compound assignments are supported by the Adams mass spectral-retention index library, which contains over 2,000 plant-derived volatile compounds. Novel molecules that are not found within vocBinBase are automatically added using strict mass spectral and experimental criteria. Users obtain fully annotated data sheets with quantitative information for all volatile compounds for studies that may consist of thousands of chromatograms. The vocBinBase database may also be queried across different studies, comprising currently 1,537 unique mass spectra generated from 1.7 million deconvoluted mass spectra of 3,435 samples (18 species). Mass spectra with retention indices and volatile profiles are available as free download under the CC-BY agreement (http://vocbinbase.fiehnlab.ucdavis.edu). The Bin

The volatile compound BinBase mass spectral database

Directory of Open Access Journals (Sweden)

Barupal Dinesh K

2011-08-01

Full Text Available Abstract Background Volatile compounds comprise diverse chemical groups with wide-ranging sources and functions. These compounds originate from major pathways of secondary metabolism in many organisms and play essential roles in chemical ecology in both plant and animal kingdoms. In past decades, sampling methods and instrumentation for the analysis of complex volatile mixtures have improved; however, design and implementation of database tools to process and store the complex datasets have lagged behind. Description The volatile compound BinBase (vocBinBase is an automated peak annotation and database system developed for the analysis of GC-TOF-MS data derived from complex volatile mixtures. The vocBinBase DB is an extension of the previously reported metabolite BinBase software developed to track and identify derivatized metabolites. The BinBase algorithm uses deconvoluted spectra and peak metadata (retention index, unique ion, spectral similarity, peak signal-to-noise ratio, and peak purity from the Leco ChromaTOF software, and annotates peaks using a multi-tiered filtering system with stringent thresholds. The vocBinBase algorithm assigns the identity of compounds existing in the database. Volatile compound assignments are supported by the Adams mass spectral-retention index library, which contains over 2,000 plant-derived volatile compounds. Novel molecules that are not found within vocBinBase are automatically added using strict mass spectral and experimental criteria. Users obtain fully annotated data sheets with quantitative information for all volatile compounds for studies that may consist of thousands of chromatograms. The vocBinBase database may also be queried across different studies, comprising currently 1,537 unique mass spectra generated from 1.7 million deconvoluted mass spectra of 3,435 samples (18 species. Mass spectra with retention indices and volatile profiles are available as free download under the CC-BY agreement (http

Volatile compounds in meat and meat products

Directory of Open Access Journals (Sweden)

Monika KOSOWSKA

Full Text Available Abstract Meaty flavor is composed of a few hundreds of volatile compounds, only minor part of which are responsible for the characteristic odor. It is developed as a result of multi-directional reactions proceeding between non-volatile precursors contained in raw meat under the influence of temperature. The volatile compounds are generated upon: Maillard reactions, lipid oxidation, interactions between Maillard reaction products and lipid oxidation products as well as upon thiamine degradation. The developed flavor is determined by many factors associated with: raw material (breed, sex, diet and age of animal, conditions and process of slaughter, duration and conditions of meat storage, type of muscle, additives applied and the course of the technological process. The objective of this review article is to draw attention to the issue of volatile compounds characteristic for meat products and factors that affect their synthesis.

Sulfur-binding in recent environments: II. Speciation of sulfur and iron and implications for the occurrence of organo-sulfur compounds

Science.gov (United States)

Hartgers, Walter A.; Lòpez, Jordi F.; Sinninghe Damsté, Jaap S.; Reiss, Christine; Maxwell, James R.; Grimalt, Joan O.

1997-11-01

Speciation of iron and sulfur species was determined for two recent sediments (La Trinitat and Lake Cisó) which were deposited in environments with a high biological productivity and sulfate-reducing activity. In sediments from calcite ponds of La Trinitat an excess of reactive iron species (iron monosulfides, iron hydroxides) results in a depletion of reactive sulfur which is accompanied by a virtual absence of organo-sulfur compounds, both in low (LMW) and high molecular-weight (HMW) fractions. Small amounts of phytanyl and highly branched isoprenoid (HBI) thiophenes in the extract demonstrate that these molecules exhibit a higher reactivity towards reduced sulfur species as compared to detrital iron. Euxinic sediments from Lake Cisó are characterised by an excess of reduced sulfur species which can rapidly trap reactive iron. High concentrations of H 2S results in the formation of organo-sulfur compounds which were encountered in both LMW and HMW fractions. The major part of the organic sulfur is bound to the carbohydrate portion of woody tissues, whose presence was revealed by a specific alkylthiophene distribution in the flash pyrolysate and by Li/EtNH 2 desulfurisation of the kerogen which resulted in the solubilisation of the sulfur-enriched hemicellulose fraction. Relatively high amounts of sulfurised C 25 HBI compounds in the sediment extract of Lake Cisó reflect the incorporation of sulfur into algal derived organic matter upon early diagenesis. The combined approach of the speciation of iron and sulfur species and the molecular analysis of sedimentary fractions demonstrates that abiotic sulfur binding to organic matter occurs at the earliest stages of diagenesis under specific depositional conditions (anoxic, stratified water column) in which an excess of reduced sulfur species relative to the amount of reactive iron is a controlling factor.

Isolation of volatile compounds of Aloe excelsa (Berger ...

African Journals Online (AJOL)

PROMOTING ACCESS TO AFRICAN RESEARCH ... Industrial and pharmacological applications of volatile and non-volatile compounds isolated ... Three commercially important compounds, namely: phenylacetonitrile, carvone and limonene were identified using gas ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

Sulfur and selenium isotope separation by distillation

International Nuclear Information System (INIS)

Mills, T. R.; McInteer, B. B.; Montoya, J. G.

1988-01-01

Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S vs. 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF 4 . 8 refs., 2 tabs

Sulfur and selenium isotope separation by distillation

International Nuclear Information System (INIS)

Mills, T.R.; McInteer, B.B.; Montoya, J.G.

1989-01-01

Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of theses isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separations of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S and 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produces separated isotopes with an effect similar to that found for sulfur in SF 4 . (author). 8 refs.; 2 tabs

Io's theothermal (sulfur) - Lithosphere cycle inferred from sulfur solubility modeling of Pele's magma supply

Science.gov (United States)

Battaglia, Steven M.; Stewart, Michael A.; Kieffer, Susan W.

2014-06-01

Surface deposits of volatile compounds such as water (Earth) or sulfur (Io) on volcanically active bodies suggest that a magmatic distillation process works to concentrate volatiles in surface reservoirs. On Earth, this is the combined hydrologic and tectonic cycle. On Io, sulfurous compounds are transferred from the interior to the surface reservoirs through a combination of a mantle-sourced magmatic system, vertical cycling of the lithosphere, and a sulfur-dominated crustal thermal system that we here call the "theothermal" system. We present a geochemical analysis of this process using previously inferred temperature and oxygen fugacity constraints of Pele's basaltic magma to determine the behavior of sulfur in the ionian magmas. Sulfate to sulfide ratios of Pele's magma are -4.084 ± 0.6 and -6.442 ± 0.7 log10 units, comparable to or lower than those of mid-ocean ridge basalts. This reflects the similarity of Io's oxidation state with Earth's depleted mantle as previously suggested by Zolotov and Fegley (Zolotov, M.Y., Fegley, B. [2000]. Geophys. Res. Lett. 27, 2789-2792). Our calculated limits of sulfur solubility in melts from Pele's patera (˜1100-1140 ppm) are also comparable to terrestrial mid-ocean ridge basalts, reflecting a compositional similarity of mantle sources. We propose that the excess sulfur obvious on Io's surface comes from two sources: (1) an insoluble sulfide liquid phase in the magma and (2) theothermal near-surface recycling.

Quantitative on-line analysis of sulfur compounds in complex hydrocarbon matrices.

Science.gov (United States)

Djokic, Marko R; Ristic, Nenad D; Olahova, Natalia; Marin, Guy B; Van Geem, Kevin M

2017-08-04

An improved method for on-line measurement of sulfur containing compounds in complex matrices is presented. The on-line system consists of a specifically designed sampling system connected to a comprehensive two-dimensional gas chromatograph (GC×GC) equipped with two capillary columns (Rtx ® -1 PONA×SGE BPX50), a flame ionization detector (FID) and a sulfur chemiluminescence detector (SCD). The result is an unprecedented sensitivity down to ppm level (1 ppm-w) for various sulfur containing compounds in very complex hydrocarbon matrices. In addition to the GC×GC-SCD, the low molecular weight sulfur containing compounds such as hydrogen sulfide (H 2 S) and carbonyl sulfide (COS) can be analyzed using a thermal conductivity detector of a so-called refinery gas analyzer (RGA). The methodology was extensively tested on a continuous flow pilot plant for steam cracking, in which quantification of sulfur containing compounds in the reactor effluent was carried out using 3-chlorothiophene as internal standard. The GC×GC-FID/-SCD settings were optimized for ppm analysis of sulfur compounds in olefin-rich (ethylene- and propylene-rich) hydrocarbon matrices produced by steam cracking of petroleum feedstocks. Besides that is primarily used for analysis of the hydrocarbon matrix, FID of the GC×GC-FID/-SCD set-up serves to double check the amount of added sulfur internal standard which is crucial for a proper quantification of sulfur compounds. When vacuum gas oil containing 780 ppm-w of elemental sulfur in the form of benzothiophenes and dibenzothiophenes is subjected to steam cracking, the sulfur balance was closed, with 75% of the sulfur contained in the feed is converted to hydrogen sulfide, 13% to alkyl homologues of thiophene while the remaining 12% is present in the form of alkyl homologues of benzothiophenes. The methodology can be applied for many other conversion processes which use sulfur containing feeds such as hydrocracking, catalytic cracking, kerogen

Supercritical fluid extraction of volatile and non-volatile compounds from Schinus molle L.

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M. S. T. Barroso

2011-06-01

Full Text Available Schinus molle L., also known as pepper tree, has been reported to have antimicrobial, antifungal, anti-inflammatory, antispasmodic, antipyretic, antitumoural and cicatrizing properties. This work studies supercritical fluid extraction (SFE to obtain volatile and non-volatile compounds from the aerial parts of Schinus molle L. and the influence of the process on the composition of the extracts. Experiments were performed in a pilot-scale extractor with a capacity of 1 L at pressures of 9, 10, 12, 15 and 20 MPa at 323.15 K. The volatile compounds were obtained by CO2 supercritical extraction with moderate pressure (9 MPa, whereas the non-volatile compounds were extracted at higher pressure (12 to 20 MPa. The analysis of the essential oil was carried out by GC-MS and the main compounds identified were sabinene, limonene, D-germacrene, bicyclogermacrene, and spathulenol. For the non-volatile extracts, the total phenolic content was determined by the Folin-Ciocalteau method. Moreover, one of the goals of this study was to compare the experimental data with the simulated yields predicted by a mathematical model based on mass transfer. The model used requires three adjustable parameters to predict the experimental extraction yield curves.

Molecular corridors and parameterizations of volatility in the chemical evolution of organic aerosols

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Y. Li

2016-03-01

Full Text Available The formation and aging of organic aerosols (OA proceed through multiple steps of chemical reaction and mass transport in the gas and particle phases, which is challenging for the interpretation of field measurements and laboratory experiments as well as accurate representation of OA evolution in atmospheric aerosol models. Based on data from over 30 000 compounds, we show that organic compounds with a wide variety of functional groups fall into molecular corridors, characterized by a tight inverse correlation between molar mass and volatility. We developed parameterizations to predict the saturation mass concentration of organic compounds containing oxygen, nitrogen, and sulfur from the elemental composition that can be measured by soft-ionization high-resolution mass spectrometry. Field measurement data from new particle formation events, biomass burning, cloud/fog processing, and indoor environments were mapped into molecular corridors to characterize the chemical nature of the observed OA components. We found that less-oxidized indoor OA are constrained to a corridor of low molar mass and high volatility, whereas highly oxygenated compounds in atmospheric water extend to high molar mass and low volatility. Among the nitrogen- and sulfur-containing compounds identified in atmospheric aerosols, amines tend to exhibit low molar mass and high volatility, whereas organonitrates and organosulfates follow high O : C corridors extending to high molar mass and low volatility. We suggest that the consideration of molar mass and molecular corridors can help to constrain volatility and particle-phase state in the modeling of OA particularly for nitrogen- and sulfur-containing compounds.

Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations.

Science.gov (United States)

Liu, Jing-yong; Huang, Shu-jie; Sun, Shui-yu; Ning, Xun-an; He, Rui-zhe; Li, Xiao-ming; Chen, Tao; Luo, Guang-qian; Xie, Wu-ming; Wang, Yu-Jie; Zhuo, Zhong-xu; Fu, Jie-wen

2015-04-01

Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na2S and Na2SO4) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na2SO4 and Na2S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO4(s) at low temperatures (incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the concentration of Si, Ca and Al-containing compounds in the sludge. These findings provide useful information for understanding the partitioning behavior of Pb, facilitating the development of strategies to control the volatilization of Pb during sludge incineration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Identification of sulfur volatiles in canned orange juices lacking orange flavor.

Science.gov (United States)

Perez-Cacho, Pilar Ruiz; Mahattanatawee, Kanjana; Smoot, John M; Rouseff, Russell

2007-07-11

The purpose of this study was to understand why some canned orange juices are not perceived as orange juice. Sensory flavor profile data indicated that the primary odor (orthonasal) attributes were tropical fruit/grapefruit, cooked/caramel, musty, and medicine. By comparison fresh-squeezed juice lacked these odor attributes. GC-O analysis found 43 odor-active components in canned juices. Eight of these aroma volatiles were sulfur based. Four of the 12 most intense aroma peaks were sulfur compounds that included methanethiol, 1-p-menth-1-ene-8-thiol, 2-methyl-3-furanthiol, and dimethyl trisulfide. The other most intense odorants included 7-methyl-3-methylene-1,6-octadiene (myrcene), octanal, 2-methoxyphenol (guaiacol), 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone (homofuraneol), (E)-non-2-enal, (E,E)-deca-2,4-dienal, 4-hydroxy-3-methoxybenzaldehyde (vanillin), and alpha-sinensal. Odorants probably responsible for the undesirable sensory attributes included grapefruit (1-p-menth-1-ene-8-thiol), cooked [2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (Furaneol), and 3-(methylthio)propanal (methional)], musty [7-methyl-3-methylene-1,6-octadiene and (E)-non-2-enal], and medicine (2-methoxyphenol). The canned juices also lacked several aldehydes and esters normally found in fresh orange juice.

Influence of physicochemical characteristics and high pressure processing on the volatile fraction of Iberian dry-cured ham.

Science.gov (United States)

Martínez-Onandi, Nerea; Rivas-Cañedo, Ana; Ávila, Marta; Garde, Sonia; Nuñez, Manuel; Picon, Antonia

2017-09-01

The volatile fraction of 30 Iberian dry-cured hams of different physicochemical characteristics and the effect of high pressure processing (HPP) at 600MPa on volatile compounds were investigated. According to the analysis of variance carried out on the levels of 122 volatile compounds, intramuscular fat content influenced the levels of 8 benzene compounds, 5 carboxylic acids, 2 ketones, 2 furanones, 1 alcohol, 1 aldehyde and 1 sulfur compound, salt concentration influenced the levels of 1 aldehyde and 1 ketone, salt-in-lean ratio had no effect on volatile compounds, and water activity influenced the levels of 3 sulfur compounds, 1 alcohol and 1 aldehyde. HPP-treated samples of Iberian ham had higher levels of 4 compounds and lower levels of 31 compounds than untreated samples. A higher influence of HPP treatment on volatile compounds than physicochemical characteristics was observed for Iberian ham. Therefore, HPP treatment conditions should be optimized in order to diminish its possible effect on Iberian ham odor and aroma characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evolution of Volatile Compounds during the Distillation of Cognac Spirit.

Science.gov (United States)

Awad, Pierre; Athès, Violaine; Decloux, Martine Esteban; Ferrari, Gérald; Snakkers, Guillaume; Raguenaud, Patrick; Giampaoli, Pierre

2017-09-06

Cognac wine spirit has a complex composition in volatile compounds which contributes to its organoleptic profile. This work focused on the batch distillation process and, in particular, on volatile compounds specifically produced by chemical reactions during the distillation of Cognac wine spirit, traditionally conducted in two steps with charentais pot stills. The aim of this study was to characterize these volatile compounds formed during distillation. Sampling has been performed on the distillates and inside the boiler during a typical Cognac distillation. The analysis of these samples allowed us to perform a mass balance and to point out several types of volatile compounds whose quantities strongly increased during the distillation process. These compounds were distinguished by their chemical family. It has been found that the first distillation step was decisive for the formation of volatile compounds. Moreover, 2 esters, 3 aldehydes, 12 norisoprenoids, and 3 terpenes were shown to be generated during the process. These results suggest that some volatile compounds found in Cognac spirit are formed during distillation due to chemical reactions induced by high temperature. These findings give important indications to professional distillers in order to enhance the product's quality.

PERUBAHAN KOMPONEN VOLATIL SELAMA FERMENTASI KECAP [Change Volatile Components During Soy Sauce Fermentation

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Anton Apriyantono1

2004-08-01

Full Text Available A study has been conducted to investigate changes of volatile components during soy sauce fermentation. During the fermentation, many volatile components produced may contribute to soy sauce flavor. THe volatile identified by GC-MS werw classified into hydrocarbon (15, alcohol (15, aldehyde (14, ester (14, ketone (9, benzene derivative (11, fatty acid (9, furan (5, terpenoid (18, pyrazine (3, thiazole (1, pyridine (1 and sulfur containing compound (2.Concentration of compounds found in almost all fermentation steps, such as hexanal and benzaldehyde did. These compounds may be derived from raw soybean, since they were all present in raw soybean and their concentration did not change during fermentation. Concentration of palmitic acid and benzeneacetaldehyde, in general, increased during all fermentation steps. They are probably derived from lipid degradation or microorganism activities. Concentrations of some fatty acids, esters and hydrocarbons, such as linoleic acid, methyl palmitate and heptadecane increased during salt fermentation only. Concentration of some other compounds, such as 2,4 decadienal decreased or undetected during fermentation.The absence of some volatile compounds, e.g. (E-nerolidol and (E,E-famesol in boiled soybean which were previously present in raw soybean may be due to evaporation of these compounds during boiling. Some volatile compounds such as, methyl heptadecanoate and few aromatic alcohols are likely derived from Aspergillus sojae, since these compounds were identified only in 0 day koji

Biodesulfurization of refractory organic sulfur compounds in fossil fuels.

Science.gov (United States)

Soleimani, Mehran; Bassi, Amarjeet; Margaritis, Argyrios

2007-01-01

The stringent new regulations to lower sulfur content in fossil fuels require new economic and efficient methods for desulfurization of recalcitrant organic sulfur. Hydrodesulfurization of such compounds is very costly and requires high operating temperature and pressure. Biodesulfurization is a non-invasive approach that can specifically remove sulfur from refractory hydrocarbons under mild conditions and it can be potentially used in industrial desulfurization. Intensive research has been conducted in microbiology and molecular biology of the competent strains to increase their desulfurization activity; however, even the highest activity obtained is still insufficient to fulfill the industrial requirements. To improve the biodesulfurization efficiency, more work is needed in areas such as increasing specific desulfurization activity, hydrocarbon phase tolerance, sulfur removal at higher temperature, and isolating new strains for desulfurizing a broader range of sulfur compounds. This article comprehensively reviews and discusses key issues, advances and challenges for a competitive biodesulfurization process.

Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

DEFF Research Database (Denmark)

FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

1992-01-01

of isotope exchange, specific radioactivities of the reduced sulfur pools were poorly defined and could not be used to calculate their rates of formation. Such isotope exchange reactions between the reduced inorganic sulfur compounds will affect the stable isotope distribution and are expected to decrease...

Effects of sulfur on lead partitioning during sludge incineration based on experiments and thermodynamic calculations

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing-yong, E-mail: www053991@126.com [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Huang, Shu-jie; Sun, Shui-yu; Ning, Xun-an; He, Rui-zhe [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Xiao-ming [Guangdong Testing Institute of Product Quality Supervision, Guangzhou 510330 (China); Chen, Tao [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Luo, Guang-qian [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China); Xie, Wu-ming; Wang, Yu-jie; Zhuo, Zhong-xu; Fu, Jie-wen [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

2015-04-15

Highlights: • A thermodynamic equilibrium calculation was carried out. • Effects of three types of sulfurs on Pb distribution were investigated. • The mechanism for three types of sulfurs acting on Pb partitioning were proposed. • Lead partitioning and species in bottom ash and fly ash were identified. - Abstract: Experiments in a tubular furnace reactor and thermodynamic equilibrium calculations were conducted to investigate the impact of sulfur compounds on the migration of lead (Pb) during sludge incineration. Representative samples of typical sludge with and without the addition of sulfur compounds were combusted at 850 °C, and the partitioning of Pb in the solid phase (bottom ash) and gas phase (fly ash and flue gas) was quantified. The results indicate that three types of sulfur compounds (S, Na{sub 2}S and Na{sub 2}SO{sub 4}) added to the sludge could facilitate the volatilization of Pb in the gas phase (fly ash and flue gas) into metal sulfates displacing its sulfides and some of its oxides. The effect of promoting Pb volatilization by adding Na{sub 2}SO{sub 4} and Na{sub 2}S was superior to that of the addition of S. In bottom ash, different metallic sulfides were found in the forms of lead sulfide, aluminosilicate minerals, and polymetallic-sulfides, which were minimally volatilized. The chemical equilibrium calculations indicated that sulfur stabilizes Pb in the form of PbSO{sub 4}(s) at low temperatures (<1000 K). The equilibrium calculation prediction also suggested that SiO{sub 2}, CaO, TiO{sub 2}, and Al{sub 2}O{sub 3} containing materials function as condensed phase solids in the temperature range of 800–1100 K as sorbents to stabilize Pb. However, in the presence of sulfur or chlorine or the co-existence of sulfur and chlorine, these sorbents were inactive. The effect of sulfur on Pb partitioning in the sludge incineration process mainly depended on the gas phase reaction, the surface reaction, the volatilization of products, and the

Potential Signatures of Semi-volatile Compounds Associated With Nuclear Processing

Energy Technology Data Exchange (ETDEWEB)

Probasco, Kathleen M.; Birnbaum, Jerome C.; Maughan, A. D.

2002-06-01

Semi-volatile chemicals associated with nuclear processes (e.g., the reprocessing of uranium to produce plutonium for nuclear weapons, or the separation of actinides from processing waste streams), can provide sticky residues or signatures that will attach to piping, ducting, soil, water, or other surface media. Volatile compounds, that are more suitable for electro-optical sensing, have been well studied. However, the semi-volatile compounds have not been well documented or studied. A majority of these semi-volatile chemicals are more robust than typical gaseous or liquid chemicals and can have lifetimes of several weeks, months, or years in the environment. However, large data gaps exist concerning these potential signature compounds and more research is needed to fill these data gaps so that important signature information is not overlooked or discarded. This report investigates key semi-volatile compounds associated with nuclear separations, identifies available chemical and physical properties, and discusses the degradation products that would result from hydrolysis, radiolysis and oxidation reactions on these compounds.

Sulfur-centered reactive intermediates derived from the oxidation of sulfur compounds of biological interest

Energy Technology Data Exchange (ETDEWEB)

Abedinzadeh, Z. [Lab. de Chimie Physique, UMR, Univ. Rene Descartes, Paris (France)

2001-02-01

Sulphur compounds play a central role in the structure and activity of many vital systems. In the living cell, sulfur constitutes an essential part of the defense against oxidative damage and is transformed into a variety of sulfur free radical species. Many studies of the chemistry of sulfur-centered radicals using pulse radiolysis and photolysis techniques to detect and measure the kinetics of these radicals have been published and reviewed. This paper discusses the present state of research on the formation and reactivity of certain sulfur-centered radicals [RS{sup .}, RSS{sup .}, RS{sup .+}, (RSSR){sup .+}] and their implications for biological systems. (author)

Sulfur-centered reactive intermediates derived from the oxidation of sulfur compounds of biological interest

International Nuclear Information System (INIS)

Abedinzadeh, Z.

2001-01-01

Sulphur compounds play a central role in the structure and activity of many vital systems. In the living cell, sulfur constitutes an essential part of the defense against oxidative damage and is transformed into a variety of sulfur free radical species. Many studies of the chemistry of sulfur-centered radicals using pulse radiolysis and photolysis techniques to detect and measure the kinetics of these radicals have been published and reviewed. This paper discusses the present state of research on the formation and reactivity of certain sulfur-centered radicals [RS . , RSS . , RS .+ , (RSSR) .+ ] and their implications for biological systems. (author)

Analysis of volatiles from irradiated yeast extract

International Nuclear Information System (INIS)

Liao Tao; Li Xin; Zu Xiaoyan; Chen Yuxia; Geng Shengrong

2013-01-01

The method for determination volatiles from irradiated yeast extract (YE) using headspace solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS) was developed in this paper. The extraction conditions were optimized with reference to the peak area and number of volatiles as aldehyde, ketone, alcohol, acid, ester and sulfur compounds. The optimized conditions of HS-SPME for volatiles in irradiated YE were: divinyl benzene/Carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber, extration time 40 min, extraction temperature 40℃. The volatiles from YE irradiated by 0-19.8 kGy were detected using HS-SPME coupled with GC-MS. The results showed that only 15 volatiles were detected from no irradiated YE and main compounds were acetic acid, 2, 3-butanediol and 1-hexanol, 2-ethyl-. There were 40 volatiles detected from irradiated YE and the main compounds were acetic acid, phenylethyl alcohol, heptanal and nonanal. Compare to no irradiated yeast extract, the aldehyde, ketone, alkene and disulfide, dimethyl were produced by irradiating process. (authors)

Effect of different drying techniques on the volatile compounds ...

African Journals Online (AJOL)

Purpose: To examine the volatile compounds, thermal stability and morphological characteristics of stevia (Stevia rebaudiana Bertoni) leaves after sun, oven and microwave drying. Methods: Gas chromatography-mass spectrometry with a spectral analysis manager was used to separate the volatile compounds. Dried stevia ...

HS-SPME-GC-MS ANALYSIS OF VOLATILE AND SEMI-VOLATILE COMPOUNDS FROM DRIED LEAVES OF Mikania glomerata Sprengel

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Esmeraldo A. Cappelaro

2015-03-01

Full Text Available This paper reports on the identification of volatile and semi-volatile compounds and a comparison of the chromatographic profiles obtained by Headspace Solid-Phase Microextraction/Gas Chromatography with Mass Spectrometry detection (HS-SPME-GC-MS of dried leaves of Mikania glomerata Sprengel (Asteraceae, also known as 'guaco.' Three different types of commercial SPME fibers were tested: polydimethylsiloxane (PDMS, polydimethylsiloxane/divinylbenzene (PDMS/DVB and polyacrylate (PA. Fifty-nine compounds were fully identified by HS-SPME-HRGC-MS, including coumarin, a marker for the quality control of guaco-based phytomedicines; most of the other identified compounds were mono- and sesquiterpenes. PA fibers performed better in the analysis of coumarin, while PDMS-DVB proved to be the best choice for a general and non-selective analysis of volatile and semi-volatile guaco-based compounds. The SPME method is faster and requires a smaller sample than conventional hydrodistillation of essential oils, providing a general overview of the volatile and semi-volatile compounds of M. glomerata.

Process for removal of sulfur compounds from fuel gases

Science.gov (United States)

Moore, Raymond H.; Stegen, Gary E.

1978-01-01

Fuel gases such as those produced in the gasification of coal are stripped of sulfur compounds and particulate matter by contact with molten metal salt. The fuel gas and salt are intimately mixed by passage through a venturi or other constriction in which the fuel gas entrains the molten salt as dispersed droplets to a gas-liquid separator. The separated molten salt is divided into a major and a minor flow portion with the minor flow portion passing on to a regenerator in which it is contacted with steam and carbon dioxide as strip gas to remove sulfur compounds. The strip gas is further processed to recover sulfur. The depleted, minor flow portion of salt is passed again into contact with the fuel gas for further sulfur removal from the gas. The sulfur depleted, fuel gas then flows through a solid absorbent for removal of salt droplets. The minor flow portion of the molten salt is then recombined with the major flow portion for feed to the venturi.

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

Directory of Open Access Journals (Sweden)

Bruno Dias Nani

Full Text Available To investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects.Seventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory-Student Survey questionnaire. Oral emanations of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide were measured using an Oral Chroma™ portable gas chromatograph. The amounts in saliva of total bacteria and seven bacteria associated with halitosis were quantified by qPCR. The in vitro production of H2S by S. moorei and/or F. nucleatum was also measured with the Oral Chroma™ instrument.The stressed students group showed increased oral emanations of hydrogen sulfide and dimethyl sulfide, together with higher salivary Solobacterium moorei levels (p < 0.05, Mann Whitney test. There were moderate positive correlations between the following pairs of variables: Fusobacterium nucleatum and S. moorei; F. nucleatum and hydrogen sulfide; Tannerella forsythia and F. nucleatum; T. forsythia and S. moorei. These correlations only occurred for the stressed group (p < 0.05, Spearman correlation. The in vitro experiment demonstrated that S. moorei increased H2S production by F. nucleatum (p < 0.05, ANOVA and Tukey's test.The increased amount of S. moorei in saliva, and its coexistence with F. nucleatum and T. forsythia, seemed to be responsible for increased oral hydrogen sulfide in the healthy male stressed subjects.

Determination of sulfur compounds in hydrotreated transformer base oil by potentiometric titration.

Science.gov (United States)

Chao, Qiu; Sheng, Han; Cheng, Xingguo; Ren, Tianhui

2005-06-01

A method was developed to analyze the distribution of sulfur compounds in model sulfur compounds by potentiometric titration, and applied to analyze hydrotreated transformer base oil. Model thioethers were oxidized to corresponding sulfoxides by tetrabutylammonium periodate and sodium metaperiodate, respectively, and the sulfoxides were titrated by perchloric acid titrant in acetic anhydride. The contents of aliphatic thioethers and total thioethers were then determined from that of sulfoxides in solution. The method was applied to determine the organic sulfur compounds in hydrotreated transformer base oil.

Oxidation of refractory sulfur compounds over Ti-containing mesoporous molecular sieves prepared by using a fluorosilicon compound.

Science.gov (United States)

Jeong, Kwang-Eun; Cho, Chin-Soo; Chae, Ho-Jeong; Kim, Chul-Ung; Jeong, Soon-Yong

2010-05-01

Titanium containing mesoporous molecular sieve (Ti-MMS) catalysts were studied for the oxidative desulfurization of refractory sulfur compounds. Ti-MMS catalysts were synthesized from fluorosilicon compounds and Ti with the hydrolysis reaction of H2SiF6 in an ammonia-surfactant mixed solution. The solid products were characterized by XRD, XRF, nitrogen adsorption, and diffuse reflectance UV-vis spectroscopy. Effects of Ti loading and oxidant/sulfur mole ratio, and sulfur species on ODS activity were investigated.

Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

Energy Technology Data Exchange (ETDEWEB)

Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

2007-07-15

The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

Effect of the type of frying culinary fat on volatile compounds isolated in fried pork loin chops by using SPME-GC-MS.

Science.gov (United States)

Ramírez, María Rosario; Estévez, Mario; Morcuende, David; Cava, Ramón

2004-12-15

The effect of the type of frying culinary fat (olive oil, sunflower oil, butter, and pig lard) on volatile compounds isolated from fried pork loin chops (m. Longissimus dorsi) was measured by SPME-GC-MS. Frying modified the fatty acid composition of lipids from pork loin chops, which tended to be similar to that of the culinary fat used to fry. Volatile compounds formed from the oxidation of fatty acids increased, such as aldehydes, ketones, alcohols, and hydrocarbons. Besides, each culinary fat used modified the volatile profiles in fried meat differently. Sunflower oil-fried pork loin chops presented the highest aldehyde aliphatic content, probably due to their highest content of polyunsaturated acids. Hexanal, the most abundant aldehyde in fried samples, presented the most elevated content in sunflower oil-fried pork loin chops. In addition, these samples presented more heterocyclic compounds from the Maillard reaction than other fried samples. Volatiles detected in olive oil-fried pork loin chops were mainly lipid-derived compounds such as pentan-1-ol, hexanal, hept-2-enal, nonanal, decanal, benzaldehyde, and nonan-2-one. Butter-fried pork loins were abundant in ketones with a high number of carbons (heptan-2-one, nonan-2-one, undecan-2-one, tridecanone, and heptadecan-2-one). Pig lard-fried pork loin chops presented some Strecker aldehydes isolated in only these samples, such as 2-methylbutanal and 3-(methylthio)propanal, and a sulfur compound (dimethyl disulfide) related to Strecker aldehydes.

Volatile compounds of Aspergillus strains with different abilities to produce ochratoxin A.

Science.gov (United States)

Jeleń, Henryk H; Grabarkiewicz-Szczesna, Jadwiga

2005-03-09

Volatile compounds emitted by Aspergillus strains having different abilities to produce ochratoxin A were investigated. Thirteen strains of Aspergillus ochraceus, three belonging to the A. ochraceus group, and eight other species of Aspergillus were examined for their abilities to produce volatile compounds and ochratoxin A on a wheat grain medium. The profiles of volatile compounds, analyzed using SPME, in all A. ochraceus strains, regardless of their toxeginicity, were similar and comprised mainly of 1-octen-3-ol, 3-octanone, 3-octanol, 3-methyl-1-butanol, 1-octene, and limonene. The prevailing compound was always 1-octen-3-ol. Mellein, which forms part of the ochratoxin A molecule, was found in both toxigenic and nontoxigenic strains. Volatile compounds produced by other Aspergillus strains were similar to those of A. ochraceus. Incubation temperatures (20, 24, and 27 degrees C) and water content in the medium (20, 30, and 40%) influenced both volatile compounds formation and ochratoxin A biosynthesis efficiency, although conditions providing the maximum amount of volatiles were different from those providing the maximum amount of ochratoxin A. The pattern of volatiles produced by toxigenic A. ochraceus strains does not facilitate their differentiation from nontoxigenic strains.

Tandem sulfur chemiluminescence and flame ionization detection with planar microfluidic devices for the characterization of sulfur compounds in hydrocarbon matrices.

Science.gov (United States)

Luong, J; Gras, R; Shellie, R A; Cortes, H J

2013-07-05

The detection of sulfur compounds in different hydrocarbon matrices, from light hydrocarbon feedstocks to medium synthetic crude oil feeds provides meaningful information for optimization of refining processes as well as demonstration of compliance with petroleum product specifications. With the incorporation of planar microfluidic devices in a novel chromatographic configuration, sulfur compounds from hydrogen sulfide to alkyl dibenzothiophenes and heavier distributions of sulfur compounds over a wide range of matrices spanning across a boiling point range of more than 650°C can be characterized, using one single analytical configuration in less than 25min. In tandem with a sulfur chemiluminescence detector for sulfur analysis is a flame ionization detector. The flame ionization detector can be used to establish the boiling point range of the sulfur compounds in various hydrocarbon fractions for elemental specific simulated distillation analysis as well as profiling the hydrocarbon matrices for process optimization. Repeatability of less than 3% RSD (n=20) over a range of 0.5-1000 parts per million (v/v) was obtained with a limit of detection of 50 parts per billion and a linear range of 0.5-1000 parts per million with a correlation co-efficient of 0.998. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of sequential fermentations and grape cultivars on volatile compounds and sensory profiles of Danish wines.

Science.gov (United States)

Liu, Jing; Arneborg, Nils; Toldam-Andersen, Torben B; Petersen, Mikael A; Bredie, Wender Lp

2017-08-01

There has been an increasing interest in the use of selected non-Saccharomyces yeasts in co-culture with Saccharomyces cerevisiae. In this work, three non-Saccharomyces yeast strains (Metschnikowia viticola, Metschnikowia fructicola and Hanseniaspora uvarum) indigenously isolated in Denmark were used in sequential fermentations with S. cerevisiae on three cool-climate grape cultivars, Bolero, Rondo and Regent. During the fermentations, the yeast growth was determined as well as key oenological parameters, volatile compounds and sensory properties of finished rosé wines. The different non-Saccharomyces strains and cool-climate grape cultivars produced wines with a distinctive aromatic profile. A total of 67 volatile compounds were identified, including 43 esters, 14 alcohols, five acids, two ketones, a C13-norisoprenoid, a lactone and a sulfur compound. The use of M. viticola in sequential fermentation with S. cerevisiae resulted in richer berry and fruity flavours in wines. The sensory plot showed a more clear separation among wine samples by grape cultivars compared with yeast strains. Knowledge on the influence of indigenous non-Saccharomyces strains and grape cultivars on the flavour generation contributed to producing diverse wines in cool-climate wine regions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Volatile and non-volatile compounds in green tea affected in harvesting time and their correlation to consumer preference.

Science.gov (United States)

Kim, Youngmok; Lee, Kwang-Geun; Kim, Mina K

2016-10-01

Current study was designed to find out how tea harvesting time affects the volatile and non-volatile compounds profiles of green tea. In addition, correlation of instrumental volatile and non-volatile compounds analyses to consumer perception were analyzed. Overall, earlier harvested green tea had stronger antioxidant capacity (~61.0%) due to the polyphenolic compounds from catechin (23,164 mg/L), in comparison to later harvested green teas (11,961 mg/L). However, high catechin content in green tea influenced negatively the consumer likings of green tea, due to high bitterness (27.6%) and astringency (13.4%). Volatile compounds drive consumer liking of green tea products were also identified, that included linalool, 2,3-methyl butanal, 2-heptanone, (E,E)-3,5-Octadien-2-one. Finding from current study are useful for green tea industry as it provide the difference in physiochemical properties of green tea harvested at different intervals.

Effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds.

Science.gov (United States)

Suzuki, Nao; Tanabe, Kazunari; Takeshita, Toru; Yoneda, Masahiro; Iwamoto, Tomoyuki; Oshiro, Sueko; Yamashita, Yoshihisa; Hirofuji, Takao

2012-03-01

The objective of this paper is to evaluate the effects of oil drops containing Lactobacillus salivarius WB21 on periodontal health and oral microbiota producing volatile sulfur compounds (VSCs). For this study, 42 subjects were randomly assigned to receive oil samples containing L. salivarius WB21 or a placebo for two weeks. Oral assessment and saliva collection were performed on days 1 and 15. Bacterial analysis was performed using the real-time polymerase chain reaction and terminal restriction fragment length polymorphism (T-RFLP). In both the experimental and placebo groups, the average probing depth, number of periodontal pockets, and the percentage of bleeding on probing (BOP) decreased while stimulated salivary flow increased on day 15. BOP was reduced in the experimental group compared with the placebo group (P = 0.010). In the experimental group, total bacterial numbers decreased, and the number of L. salivarius increased. The number of Prevotella intermedia, which is correlated with hydrogen sulfide concentration in mouth air, increased in the placebo group and did not change in the experimental group. T-RFLP analysis found that the peak area proportions representing Porphyromonas gingivalis, P. intermedia, Tannerella forsythensis, and Fusobacterium nucleatum decreased in the experimental group, although there was no significant change in the bacterial composition. Thus we observed oil drops containing L. salivarius WB21 improved BOP and inhibited the reproduction of total and VSC-producing periodontopathic bacteria compared with the placebo group, but also showed the limit of its efficacy in controlling VSCs producing and periodontal pathogens.

Biogenic volatile organic compounds in the Earth system.

Science.gov (United States)

Laothawornkitkul, Jullada; Taylor, Jane E; Paul, Nigel D; Hewitt, C Nicholas

2009-01-01

Biogenic volatile organic compounds produced by plants are involved in plant growth, development, reproduction and defence. They also function as communication media within plant communities, between plants and between plants and insects. Because of the high chemical reactivity of many of these compounds, coupled with their large mass emission rates from vegetation into the atmosphere, they have significant effects on the chemical composition and physical characteristics of the atmosphere. Hence, biogenic volatile organic compounds mediate the relationship between the biosphere and the atmosphere. Alteration of this relationship by anthropogenically driven changes to the environment, including global climate change, may perturb these interactions and may lead to adverse and hard-to-predict consequences for the Earth system.

Aroma volatile compounds from two fresh pineapple varieties in China.

Science.gov (United States)

Zheng, Liang-Yong; Sun, Guang-Ming; Liu, Yu-Ge; Lv, Ling-Ling; Yang, Wen-Xiu; Zhao, Wei-Feng; Wei, Chang-Bin

2012-01-01

Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 μg·kg(-1) and 380.66 μg·kg(-1) in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs) of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthio)propanoic acid methyl ester, 3-(methylthio)propanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthio)propanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple.

Aroma Volatile Compounds from Two Fresh Pineapple Varieties in China

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Chang-Bin Wei

2012-06-01

Full Text Available Volatile compounds from two pineapples varieties (Tainong No.4 and No.6 were isolated by headspace solid phase microextraction (HS-SPME and identified and quantified by gas chromatography-mass spectrometry (GC/MS. In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 µg·kg⁻¹ and 380.66 µg·kg⁻¹ in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthiopropanoic acid methyl ester, 3-(methylthiopropanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthiopropanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple.

Aroma Volatile Compounds from Two Fresh Pineapple Varieties in China

Science.gov (United States)

Zheng, Liang-Yong; Sun, Guang-Ming; Liu, Yu-Ge; Lv, Ling-Ling; Yang, Wen-Xiu; Zhao, Wei-Feng; Wei, Chang-Bin

2012-01-01

Volatile compounds from two pineapples varieties (Tainong No.4 and No.6) were isolated by headspace solid phase microextraction (HS-SPME) and identified and quantified by gas chromatography-mass spectrometry (GC/MS). In the Tainong No. 4 and No. 6 pineapples, a total of 11 and 28 volatile compounds were identified according to their retention time on capillary columns and their mass spectra, and quantified with total concentrations of 1080.44 μg·kg−1 and 380.66 μg·kg−1 in the Tainong No.4 and No. 6 pineapples, respectively. The odor active values (OAVs) of volatile compounds from pineapples were also calculated. According to the OAVs, four compounds were defined as the characteristic aroma compounds for the Tainong No. 4 pineapple, including furaneol, 3-(methylthio)propanoic acid methyl ester, 3-(methylthio)propanoic acid ethyl ester and δ-octalactone. The OAVs of five compounds including ethyl-2-methylbutyrate, methyl-2-methylbutyrate, 3-(methylthio)propanoic acid ethyl ester, ethyl hexanoate and decanal were considered to be the characteristic aroma compounds for the Tainong No. 6 pineapple. PMID:22837701

Development of Volatile Compounds during Hydrolysis of Porcine Hemoglobin with Papain

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Kathrine Holmgaard Bak

2018-02-01

Full Text Available There is a growing market for the use of hydrolysates from animal side-streams for production of high-protein supplements. However, there can be issues with development of off-flavors, either due to the raw material in question or due to the hydrolysis process itself. This study examined the development of volatile compounds during hydrolysis of hemoglobin. Briefly, porcine hemoglobin was hydrolyzed by 0.5% papain for up to 5 h, and the development of volatile compounds was analyzed via gas chromatography-mass spectrometry. The results showed that there was significant development of a number of volatile compounds with time, e.g., certain Maillard reaction and lipid oxidation products, which are likely candidates for the aroma development during hydrolysis. Furthermore, it was shown that development of a number of the volatiles was due to the hydrolysis process, as these compounds were not found in a control without enzyme.

Analysis of volatile compounds of Malaysian Tualang ( Koompassia ...

African Journals Online (AJOL)

Analysis of volatile compounds of Malaysian Tualang ( Koompassia excelsa ) honey using gas chromatography mass spectrometry. ... Other classes of chemical compounds detected included acids, aldehydes, alcohols, ketones, terpenes, furans and a miscellaneous group. Methanol yielded the highest number of extracted ...

Measuring volatile organic compounds and stable isotopes emitted from trees and soils of the Biosphere 2 Rainforest

Science.gov (United States)

Meraz, J. C.; Meredith, L. K.; Van Haren, J. L. M.; Volkmann, T. H. M.

2017-12-01

Rainforest trees and soils play an important role in volatile organic compound (VOC) emissions. It is known that many rainforest tree species emit these organic compounds, such as terpenes, which can have an impact on the atmosphere and can be indicative of their metabolic functions. Some VOCs also absorb infrared radiation at wavelengths at which water isotopes are measured with laser spectrometers. Normal concentrations are not high enough for ambient sampling, but increased concentrations resulting from soil and plant samples extracted using equilibrium methods affect observed isotope ratios. There is thus a need to characterize volatile emissions from soil and plant samples, and to develop better methods to account for VOC interference during water isotope measurements. In this study, we collected soil and leaf samples from plants of the Biosphere 2 Rainforest Biome, a mesocosm system created to stimulate natural tropical rainforest habitats . Volatile concentrations were measured using a Gasmet DX4015 FTIR analyzer and a custom sampling system with sulfur hexafluoride (SF6) used as a tracer gas to test for leakage, and a commercial laser spectrometer was used for isotopic analysis. We determined that the different types of tree species emit different kinds of VOCs, such as isoprenes, alcohols, and aldehydes, that will potentially have to be accounted for. This study will help build the understanding of which organic compounds are emitted and develop new methods to test for water isotopes and gas fluxes in clear and precise measures. Such measures can help characterize the functioning of environmental systems such as the Biosphere 2 Rainforest Biome.

Effect of γ-irradiation on volatile compounds of dried Welsh onion (Allium fistulosum L.)

International Nuclear Information System (INIS)

Gyawali, Rajendra; Seo, Hye-Young; Lee, Hyun-Ju; Song, Hyun-Pa; Kim, Dong-Ho; Byun, Myung-Woo; Kim, Kyong-Su

2006-01-01

The volatile compounds of γ-irradiated dried Welsh onion were isolated by simultaneous distillation-extraction (SDE) technique and then analyzed by gas chromatography-mass spectrometry (GC-MS) along with their non-irradiated counterparts. A total of 35 volatile compounds were identified in non-irradiated and 1 kGy irradiated samples and 36 volatile compounds were identified in 3, 5, 10 and 20 kGy irradiated samples so far belong to chemical classes of acid, alcohol, aldehyde, ester, furan, ketone and S-containing compound. S-containing compounds were detected as major volatile compounds of all experimental samples. Though the content of several compounds was increased after irradiation, content of major S-containing compounds was found to decreased in the process. Application of high-dose irradiation if required for microbial decontamination of dried Welsh onion is feasible as it enhanced the total concentration of volatile compounds by 31.60% and 24.85% at 10 and 20 kGy, respectively

VOLATILE COMPOUNDS IDENTIFIED IN BARBADOS CHERRY ‘BRS-366 JABURÚ’

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Y. M. Garcia

2016-07-01

Full Text Available In foods, the flavor and aroma are very important attributes, thus the main objective of this study was to identify the volatile compounds (VC of the "BRS-366 Jaburú" acerola variety, for which we used the solid phase microextraction method (SPE. The separation and identification of volatile compounds was made using gas chromatography-mass spectrometry (GC-MS. Three fibers were evaluated, Polydimethylsiloxane / Divinylbenzene (PDMS / DVB, 65 micrometres Divinylbenzene / Carboxen / Polydimethylsiloxane (DVB / CAR / PDMS 50/30 m and polyacrylate (PA 85 uM to compare the extraction of its components. Thirty-three volatile compounds were identified and classified into eight chemical classes: carboxylic acids, alcohols, aldehydes, ketones, esters, hydrocarbons, phenylpropanoids and terpenoids. The peak areas of each of the extracted compounds were expressed as percentages to indicate the relative concentration of each, of which ethyl acetate is distinguished by being responsible for the fruity aroma notes. Thus, the fiber PDMS / DVB was the best as it enabled to extract a greater amount of volatile compounds

Volatile compounds and sensory properties of Montasio cheese made from the milk of Simmental cows grazing on alpine pastures.

Science.gov (United States)

Bovolenta, S; Romanzin, A; Corazzin, M; Spanghero, M; Aprea, E; Gasperi, F; Piasentier, E

2014-12-01

The aim of this study was to analyze the volatile compounds, physicochemical characteristics, and sensory properties of Montasio, a semicooked pressed cheese, produced from the milk of the dual-purpose Italian Simmental cows grazing on alpine pastures. A total of 72 cows grazing on 2 pastures, which differed in botanical composition (nutrient-rich pasture vs. nutrient-poor pasture), received 2 different levels of supplementation (3.0 vs 1.5 kg/head per day). The experimental cheeses were produced from whole, raw milk and ripened for 60 d. Sixty-one volatile compounds, including alcohols (11), aldehydes (6), ketones (10), lactones (2), esters (6), hydrocarbons (3), carboxylic acids (6), phenolic compounds (4), monoterpenes (7), sesquiterpenes (1), sulfur compounds (4), and amines (1), were detected. The main families in terms of relative weight appeared to be carboxylic acids, esters, and alcohols. A panel of trained assessors described the experimental cheeses as having an intense color; small and evenly distributed eyes; an intense odor and flavor of milk-sour, milk, and cow; and a tender and creamy texture. The pasture type affected the volatile fraction, particularly ketones, phenolic compounds, and terpenes, which are overall higher in nutrient-poor pastures. A slight effect on the sensory analyses, in particular the effect of the cow attribute on odor and flavor, was perceived by the panelists. The cheeses produced on nutrient-rich pasture had higher b* (yellowness) index. These results were consistent with the color evaluation of the sensory panel. In addition, the pasture affected some textural attributes (adhesivity, creaminess, and granules) as perceived by the panelists. Concentrate supplementation, which is required to meet the feeding requirements of grazing cows, had no clear effect on either the volatile compounds or the sensory properties of the cheeses. Thus, at least within levels of integration adopted, it is expected not to alter the organoleptic

Effect of γ-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

International Nuclear Information System (INIS)

Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok; Seo, Hye-young; Kim, Hee-Yeon; Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo; Kwon, Joong-Ho; Kim, Kyong-Su

2009-01-01

A study was carried out to find the effect of γ-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix (Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, (E)-carveol, (E,E)-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of γ-irradiation on medicinal herb.

Effect of {gamma}-irradiation on the volatile compounds of medicinal herb, Paeoniae Radix

Energy Technology Data Exchange (ETDEWEB)

Shim, Sung-Lye; Hwang, In-Min; Ryu, Keun-Young; Jung, Min-Seok [Department of Food and Nutrition, Chosun University (Korea, Republic of); Seo, Hye-young [Korea Food Research Institute (Korea, Republic of); Kim, Hee-Yeon [Korea Food and Drug Administration (Korea, Republic of); Song, Hyun-Pa; Kim, Jae-Hun; Lee, Ju-Woon; Byun, Myung-Woo [Advanced Radiation Technology Institute, KAERI, Jeongeup 580-185 (Korea, Republic of); Kwon, Joong-Ho [Department of Food Science and Technology, Kyungpook National University (Korea, Republic of); Kim, Kyong-Su [Korea Food Research Institute (Korea, Republic of)], E-mail: kskim@chosun.ac.kr

2009-07-15

A study was carried out to find the effect of {gamma}-irradiation on contents of volatile compounds from medicinal herb, Paeoniae Radix (Paenia albiflora Pallas var. trichocarpa Bunge). The volatile compounds of control, 1, 3, 5 and 10 kGy irradiated samples were extracted by simultaneous steam distillation and extraction (SDE) method and analyzed by gas chromatograph-mass spectrometer. The major volatile compounds were paeonol, (E)-carveol, (E,E)-2,4-octadienal, methyl salicylate, myrtanol and eugenol acetate. Volatile compounds belonging to chemical classes of acids, alcohols, aldehydes, esters, hydrocarbons and miscellaneous were identified in all experimental samples. The types of volatile compounds in irradiated samples were similar to those of non-irradiated sample and the concentrations of these compounds differed between treatments. 1,3-Bis (1,1-dimethylethyl)-benzene was identified by using the selected ion monitoring (GC/MS-SIM) mode. The concentration of this compound increased with the increase of irradiation dose level. These results suggest that it could be used as the base data for the effect of {gamma}-irradiation on medicinal herb.

Sulfur volatiles from Allium spp. affect Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), response to citrus volatiles.

Science.gov (United States)

Mann, R S; Rouseff, R L; Smoot, J M; Castle, W S; Stelinski, L L

2011-02-01

The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors Candidatus Liberibacter asiaticus (Las) and Candidatus Liberibacter americanus (Lam), the presumed causal agents of huanglongbing. D. citri generally rely on olfaction and vision for detection of host cues. Plant volatiles from Allium spp. (Alliaceae) are known to repel several arthropod species. We examined the effect of garlic chive (A. tuberosum Rottl.) and wild onion (A. canadense L.) volatiles on D. citri behaviour in a two-port divided T-olfactometer. Citrus leaf volatiles attracted significantly more D. citri adults than clean air. Volatiles from crushed garlic chive leaves, garlic chive essential oil, garlic chive plants, wild onion plants and crushed wild onion leaves all repelled D. citri adults when compared with clean air, with the first two being significantly more repellent than the others. However, when tested with citrus volatiles, only crushed garlic chive leaves and garlic chive essential oil were repellent, and crushed wild onions leaves were not. Analysis of the headspace components of crushed garlic chive leaves and garlic chive essential oil by gas chromatography-mass spectrometry revealed that monosulfides, disulfides and trisulfides were the primary sulfur volatiles present. In general, trisulfides (dimethyl trisulfide) inhibited the response of D. citri to citrus volatiles more than disulfides (dimethyl disulfide, allyl methyl disulfide, allyl disulfide). Monosulfides did not affect the behaviour of D. citri adults. A blend of dimethyl trisulfide and dimethyl disulfide in 1:1 ratio showed an additive effect on inhibition of D. citri response to citrus volatiles. The plant volatiles from Allium spp. did not affect the behaviour of the D. citri ecto-parasitoid Tamarixia radiata (Waterston). Thus, Allium spp. or the tri- and di-sulphides could be integrated into management programmes for D. citri without affecting natural enemies.

Changes in volatile compound composition of Antrodia camphorata during solid state fermentation.

Science.gov (United States)

Xia, Yongjun; Zhang, Baorong; Li, Weijiang; Xu, Ganrong

2011-10-01

Although the volatiles present in mushrooms and fungi have been investigated by many researchers, including Antrodia camphorata in submerged fermentation, there are few data available regarding changes in volatile compounds during fermentation. Our research has revealed that solid state fermentation of A. camphorata is highly odiferous compared with submerged cultures and the odor changed with increasing culture time. Therefore the aim of this study was to investigate the changes in volatile compound composition of A. camphorata during solid state fermentation. Altogether, 124 major volatile compounds were identified. The volatile compounds produced by A. camphorata during growth in solid state fermentation were quite different. Oct-1-en-3-ol, octan-3-one and methyl 2-phenylacetate were predominant in exponential growth phase production, while the dominant volatiles produced in stationary phase were octan-3-one and methyl 2-phenylacetate. In stationary phase, lactone compounds in A. camphorata, such as 5-butyloxolan-2-one, 5-heptyloxolan-2-one, 6-heptyloxan-2-one, contributed greatly to peach and fruit-like flavor. Terpene and terpene alcohol compounds, such as 1-terpineol, L-linalool, T-cadinol, (E, E)-farnesol, β-elemene, cis-α-bisabolene and α-muurolene, made different contributions to herbal fresh aroma in A. camphorata. Nineteen volatile sesquiterpenes were detected from solid state fermentation of A. camphorata. The compounds 5-n-butyl-5H-furan-2-one, β-ionone, (-)-caryophyllene oxide, aromadendrene oxide, diepi-α-cedrene epoxide, β-elemene, α-selinene, α-muurolene, azulene, germacrene D, γ-cadinene and 2-methylpyrazine have not hitherto been reported in A. camphorata. The preliminary results suggest that the aroma-active compounds produced by A camphorata in solid state fermentation might serve as an important source of natural aroma compounds for the food and cosmetic industries or antibiotic activity compounds. The sesquiterpenes could be

Development of Volatile Compounds during Hydrolysis of Porcine Hemoglobin with Papain

DEFF Research Database (Denmark)

Bak, Kathrine Holmgaard; Petersen, Mikael Agerlin; Lametsch, Rene

2018-01-01

of volatile compounds with time, e.g., certain Maillard reaction and lipid oxidation products, which are likely candidates for the aroma development during hydrolysis. Furthermore, it was shown that development of a number of the volatiles was due to the hydrolysis process, as these compounds were not found...

Current emission trends for nitrogen oxides, sulfur dioxide, and volatile organic compounds by month and state: Methodology and results

International Nuclear Information System (INIS)

Kohout, E.J.; Miller, D.J.; Nieves, L.A.; Rothman, D.S.; Saricks, C.L.; Stodolsky, F.; Hanson, D.A.

1990-08-01

This report presents estimates of monthly sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and nonmethane voltatile organic compound (VOC) emissions by sector, region, and state in the contiguous United States for the years 1975 through 1988. This work has been funded as part of the National Acid Precipitation Assessment Program's Emissions and Controls Task Group by the US Department of Energy (DOE) Office of Fossil Energy (FE). The DOE project officer is Edward C. Trexler, DOE/FE Office of Planning and Environment

Volatile organic compounds in emissions from brown-coal-fired residential stoves

International Nuclear Information System (INIS)

Engewald, W.; Knobloch, T.; Efer, J.

1993-01-01

Volatile organic compounds were determined in stack-gas emissions from the residential burning of brown-coal briquets using adsorptive enrichment on hydrophobic adsorbents, thermal desorption and capillary-gas chromatographic analysis. 152 compounds were identified and quantified. Quantitative emission factors of the identified individual compounds were determined in relation to the amount of the fuel used. These factors permit assessment of the pollution of the city of Leipzig with volatile organic compounds resulting from the burning of indigenous lignite. (orig.) [de

Isotopically labeled sulfur compounds and synthetic selenium and tellurium analogues to study sulfur metabolism in marine bacteria

Directory of Open Access Journals (Sweden)

Nelson L. Brock

2013-05-01

Full Text Available Members of the marine Roseobacter clade can degrade dimethylsulfoniopropionate (DMSP via competing pathways releasing either methanethiol (MeSH or dimethyl sulfide (DMS. Deuterium-labeled [2H6]DMSP and the synthetic DMSP analogue dimethyltelluriopropionate (DMTeP were used in feeding experiments with the Roseobacter clade members Phaeobacter gallaeciensis DSM 17395 and Ruegeria pomeroyi DSS-3, and their volatile metabolites were analyzed by closed-loop stripping and solid-phase microextraction coupled to GC–MS. Feeding experiments with [2H6]DMSP resulted in the incorporation of a deuterium label into MeSH and DMS. Knockout of relevant genes from the known DMSP demethylation pathway to MeSH showed in both species a residual production of [2H3]MeSH, suggesting that a second demethylation pathway is active. The role of DMSP degradation pathways for MeSH and DMS formation was further investigated by using the synthetic analogue DMTeP as a probe in feeding experiments with the wild-type strain and knockout mutants. Feeding of DMTeP to the R. pomeroyi knockout mutant resulted in a diminished, but not abolished production of demethylation pathway products. These results further corroborated the proposed second demethylation activity in R. pomeroyi. Isotopically labeled [2H3]methionine and 34SO42−, synthesized from elemental 34S8, were tested to identify alternative sulfur sources besides DMSP for the MeSH production in P. gallaeciensis. Methionine proved to be a viable sulfur source for the MeSH volatiles, whereas incorporation of labeling from sulfate was not observed. Moreover, the utilization of selenite and selenate salts by marine alphaproteobacteria for the production of methylated selenium volatiles was explored and resulted in the production of numerous methaneselenol-derived volatiles via reduction and methylation. The pathway of selenate/selenite reduction, however, proved to be strictly separated from sulfate reduction.

Screening and identification of phytotoxic volatile compounds in medicinal plants and characterizations of a selected compound, eucarvone.

Science.gov (United States)

Sunohara, Yukari; Baba, Yohei; Matsuyama, Shigeru; Fujimura, Kaori; Matsumoto, Hiroshi

2015-07-01

Screening and identification of phytotoxic volatile compounds were performed using 71 medicinal plant species to find new natural compounds, and the characterization of the promising compound was investigated to understand the mode of action. The volatile compounds from Asarum sieboldii Miq. showed the strongest inhibitory effect on the hypocotyl growth of lettuce seedlings (Lactuca sativa L.cv. Great Lakes 366), followed by those from Schizonepeta tenuifolia Briquet and Zanthoxylum piperitum (L.) DC.. Gas chromatography-mass spectrometry (GC/MS) identified four volatile compounds, α-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), β-pinene (6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane), 3-carene (3,7,7-trimethylbicyclo[4.1.0]hept-3-ene), and eucarvone (2,6,6-trimethy-2,4-cycloheptadien-1-one), from A. sieboldii, and three volatile compounds, limonene (1-methyl-4-(1-methylethenyl)-cyclohexene), menthone (5-methyl-2-(propan-2-yl)cyclohexan-1-one), and pulegone (5-methyl-2-propan-2-ylidenecyclohexan-1-one), from S. tenuifolia. Among these volatile compounds, eucarvone, menthone, and pulegone exhibited strong inhibitory effects on both the root and shoot growth of lettuce seedlings. Eucarvone-induced growth inhibition was species-selective. Cell death, the generation of reactive oxygen species (ROS), and lipid peroxidation were induced in susceptible finger millet seedlings by eucarvone treatment, whereas this compound (≤158 μM) did not cause the increase of lipid peroxidation and ROS production in tolerant maize. The results of the present study show that eucarvone can have strong phytotoxic activity, which may be due to ROS overproduction and subsequent oxidative damage in finger millet seedlings.

[Distribution and sources of oxygen and sulfur heterocyclic aromatic compounds in surface soil of Beijing, China].

Science.gov (United States)

He, Guang-Xiu; Zhang, Zhi-Huan; Peng, Xu-Yang; Zhu, Lei; Lu, Ling

2011-11-01

62 surface soil samples were collected from different environmental function zones in Beijing. Sulfur and oxygen heterocyclic aromatic compounds were detected by GC/MS. The objectives of this study were to identify the composition and distribution of these compounds, and discuss their sources. The results showed that the oxygen and sulfur heterocyclic aromatic compounds in the surface soils mainly contained dibenzofuran, methyl- and C2-dibenzofuran series, dibenzothiophene, methyl-, C2- and C3-dibenzothiophene series and benzonaphthothiophene series. The composition and distribution of the oxygen and sulfur heterocyclic aromatic compounds in the surface soil samples varied in the different environmental function zones, of which some factories and the urban area received oxygen and sulfur heterocyclic aromatic compounds most seriously. In Beijing, the degree of contamination by oxygen and sulfur heterocyclic aromatic compounds in the north surface soil was higher than that in the south. There were preferable linear correlations between the concentration of dibenzofuran series and fluorene series, as well as the concentration of dibenzothiophene series and dibenzofuran series. The oxygen and sulfur heterocyclic aromatic compounds in the surface soil were mainly derived from combustion products of oil and coal and direct input of mineral oil, etc. There were some variations in pollution sources of different environmental function zones.

Relationship between sensory attributes and volatile compounds of polish dry-cured loin

Science.gov (United States)

Górska, Ewa; Nowicka, Katarzyna; Jaworska, Danuta; Przybylski, Wiesław; Tambor, Krzysztof

2017-01-01

Objective The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods The volatile compounds were investigated by using solid phase microextraction (SPME) and gas chromatography–mass spectrometry (GC–MS). For sensory assessment, the quantitative descriptive analysis (QDA) method was used. Results A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively). The dominant compounds were: aromatic hydrocarbon (toluene); alkanes (hexane, heptane, and 2,2,4-trimethylpentane); aldehyde (hexanal); alcohol (2-furanmethanol); ketone (3-hydroxy-2-butanone); phenol (guaiacol); and terpenes (eucalyptol, cymene, γ-terpinen, and limonene). Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production. PMID:27456422

Relationship between sensory attributes and volatile compounds of polish dry-cured loin

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Ewa Górska

2017-05-01

Full Text Available Objective The aim of this work was to determine the relationship between objective sensory descriptors and volatile flavour compound composition of Polish traditional dry-cured loin. Methods The volatile compounds were investigated by using solid phase microextraction (SPME and gas chromatography–mass spectrometry (GC–MS. For sensory assessment, the quantitative descriptive analysis (QDA method was used. Results A total of 50 volatile compounds were found and assigned to 17 chemical families. Most of the detected volatile compounds derived from smoking, lipid oxidative reactions and seasoning (46.8%, 21.7%, and 18.9%, respectively. The dominant compounds were: aromatic hydrocarbon (toluene; alkanes (hexane, heptane, and 2,2,4-trimethylpentane; aldehyde (hexanal; alcohol (2-furanmethanol; ketone (3-hydroxy-2-butanone; phenol (guaiacol; and terpenes (eucalyptol, cymene, γ-terpinen, and limonene. Correlation analysis showed that some compounds derived from smoking were positively correlated with the intensity of cured meat odour and flavour and negatively with the intensity of dried meat odour and flavour, while terpenes were strongly correlated with odour and flavour of added spices. Conclusion The analysed dry-cured loins were characterized by specific and unique sensory profile. Odour and flavour of studied loins was mainly determined by volatile compounds originating from smoking, seasoning and lipid oxidation. Obtained results suggest that smoking process is a crucial stage during Polish traditional dry-cured loins production.

Volatile compounds in samples of cork and also produced by selected fungi.

Science.gov (United States)

Barreto, M C; Vilas Boas, L; Carneiro, L C; San Romão, M V

2011-06-22

The production of volatile compounds by microbial communities of cork samples taken during the cork manufacturing process was investigated. The majority of volatiles were found in samples collected at two stages: resting after the first boiling and nontreated cork disks. Volatile profiles produced by microbiota in both stages are similar. The releasable volatile compounds and 2,4,6-trichloroanisole (TCA) produced in cork-based culture medium by five isolated fungal species in pure and mixed cultures were also analyzed by gas chromatography coupled with mass spectrometry (GC-MS).The results showed that 1-octen-3-ol and esters of fatty acids (medium chain length C8-C20) were the main volatile compounds produced by either pure fungal species or their mixture. Apparently, Penicillium glabrum is the main contributor to the overall volatile composition observed in the mixed culture. The production of releasable TCA on cork cannot be attributed to any of the assayed fungal isolates.

Characterisation of selected volatile organic compounds in ...

African Journals Online (AJOL)

kshale

2013-05-15

May 15, 2013 ... have entered the commercial market, both in rural areas ... nation of volatile compounds include: gas chromate- graphy (GC) ... prior to the actual analysis, various extraction methods ..... traditional and industrial 'orujo' spirits.

Major Odorants Released as Urinary Volatiles by Urinary Incontinent Patients

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In Young Sa

2013-07-01

Full Text Available In this study, volatile urinary components were collected using three different types of samples from patients suffering from urinary incontinence (UI: (1 urine (A; (2 urine + non-used pad (B; and (3 urine + used pad (C. In addition, urine + non-used pad (D samples from non-patients were also collected as a reference. The collection of urinary volatiles was conducted with the aid of a glass impinger-based mini-chamber method. Each of the four sample types (A through D was placed in a glass impinger and incubated for 4 hours at 37 °C. Ultra pure air was then passed through the chamber, and volatile urine gas components were collected into Tedlar bags at the other end. These bag samples were then analyzed for a wide range of VOCs and major offensive odorants (e.g., reduced sulfur compounds (RSCs, carbonyls, trimethylamine (TMA, ammonia, etc.. Among the various odorants, sulfur compounds (methanethiol and hydrogen sulfide and aldehydes (acetaldehyde, butylaldehyde, and isovaleraldehyde were detected above odor threshold and predicted to contribute most effectively to odor intensity of urine incontinence.

Interactive effects of vertical mixing, solar radiation and microbial activity on oceanic dimethylated sulfur cycling

OpenAIRE

Galí Tàpias, Martí

2012-01-01

The production and subsequent emission of volatile compounds is one of the numerous ways by which microbial plankton participate in the cycling of elements and influence the Earth's climate. Dimethylsulfide (DMS), produced by enzymatic decomposition of the algal intracellular compound dimethylsulfoniopropionate (DMSP), is the more abundant organic volatile in the upper ocean. Its global emission amounts ca. 28 Tg S per year, and represents the main biogenic source of sulfur to the troposphere...

Comparison of comprehensive two-dimensional gas chromatography coupled with sulfur-chemiluminescence detector to standard methods for speciation of sulfur-containing compounds in middle distillates.

Science.gov (United States)

Ruiz-Guerrero, Rosario; Vendeuvre, Colombe; Thiébaut, Didier; Bertoncini, Fabrice; Espinat, Didier

2006-10-01

The monitoring of total sulfur content and speciation of individual sulfur-containing compounds in middle distillates is required for efficient catalyst selection and for a better understanding of the kinetics of the reactions involved in hydrotreament processes. Owing to higher resolution power and enhanced sensitivity, comprehensive two-dimensional gas chromatography (GCxGC) hyphenated to sulfur chemiluminescence detection (SCD) has recently evolved as a powerful tool for improving characterization and identification of sulfur compounds. The aim of this paper is to compare quantitatively GCxGC-SCD and various other methods commonly employed in the petroleum industry, such as X-ray fluorescence, conventional GC-SCD, and high-resolution mass spectrometry, for total sulfur content determination and speciation analysis. Different samples of middle distillates have been analyzed to demonstrate the high potential and important advantages of GCxGC-SCD for innovative and quantitative analysis of sulfur-containing compounds. More accurate and detailed results for benzothiophenes and dibenzothiophenes are presented, showing that GCxGC-SCD should become, in the future, an essential tool for sulfur speciation analysis.

Total volatile organic compounds (TVOC) in indoor air quality investigations

DEFF Research Database (Denmark)

Mølhave, L.; Clausen, Geo; Berglund, B.

1997-01-01

The amount of volatile organic compounds (VOCs) in indoor air, usually called TVOC (total volatile organic compounds), has been measured using different definitions and techniques which yield different results. This report recommends a definition of TVOC referring to a specified range of VOCs...... for characterizing indoor pollution and for improving source control as required from the points of view of health, comfort, energy efficiency and sustainability. (C) Indoor Air (1997)....

Sulfur compounds and species in Russian residues by XPS and PY-GC-PFPO

Energy Technology Data Exchange (ETDEWEB)

Quan, S.; Suoqi, Z.; Chunming, X. [University of Petroleum, State Key Laboraory of Heavy Oil Processing, Beijing (China); Kotlyar, L.; Kung, J. [National Research Council of Canada, Institute for Chemical processand Environmental Technology, Ottawa, ON (Canada); Chung, K. H. [Syncrude Canada Limited, Edmonton, AB (Canada)

2004-07-01

Distribution and structure of sulfur components of Russian crude oil were investigated by separating vacuum residues from the oil into 17 narrow cuts and one end-cut using the supercritical fluid extraction and fractionation technique (SFEF). The cuts were analyzed by gas chromatography, with conditions optimized from 600 degrees C to 1,000 degrees C, and between two and twenty seconds. In general, the total amount of of the sulfur compounds in pyrolizates was found to be proportional to the sulfur content in the vacuum residues. Thiophenes, benzothiophenes and dibenzothiophene content varied from vacuum residue to vacuum residue. Benzothiophens were identified as the dominant sulfur compounds in the pyrolizate of Russian crude oil.

Analysis of seven salad rocket (Eruca sativa) accessions: The relationships between sensory attributes and volatile and non-volatile compounds.

Science.gov (United States)

Bell, Luke; Methven, Lisa; Signore, Angelo; Oruna-Concha, Maria Jose; Wagstaff, Carol

2017-03-01

Sensory and chemical analyses were performed on accessions of rocket (Eruca sativa) to determine phytochemical influences on sensory attributes. A trained panel was used to evaluate leaves, and chemical data were obtained for polyatomic ions, amino acids, sugars and organic acids. These chemical data (and data of glucosinolates, flavonols and headspace volatiles previously reported) were used in Principal Component Analysis (PCA) to determine variables statistically important to sensory traits. Significant differences were observed between samples for polyatomic ion and amino acid concentrations. PCA revealed strong, positive correlations between glucosinolates, isothiocyanates and sulfur compounds with bitterness, mustard, peppery, warming and initial heat mouthfeel traits. The ratio between glucosinolates and sugars inferred reduced perception of bitter aftereffects. We highlight the diversity of E. sativa accessions from a sensory and phytochemical standpoint, and the potential for breeders to create varieties that are nutritionally and sensorially superior to existing ones. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Development of volatile compounds in processed cheese during storage

DEFF Research Database (Denmark)

Sunesen, Lars Oddershede; Lund, Pia; Sørensen, J.

2002-01-01

The purpose of this work teas to study tire impact of storage conditions, such as light and temperature, on the development of volatile compounds to processed cheese. Cheese in glass containers was stored at 5, 20 or 37 degreesC in light or darkness for up to 1 yr. Dynamic headspace and gas...... chromatography/mass spectrometry leas used for quantifying 28 volatile organic compounds at eight stages during tree storage period. Through principal component analysis, three important storage parameters could be identified. Principal components 1, 2 and 3 reflected storage tinge, conditions of light...

Inventory of volatile organic compound emissions in Finland, 1985

International Nuclear Information System (INIS)

Mroueh, U.M.

1988-01-01

The aim of the study was to compile an inventory of the emissions of volatile organic compounds in Finland for the year 1985. The report was prepared for the ECE Task Force on Emissions of Volatile Organic Compounds from Stationary Sources according to the classification given by the Task Force. It considers anthropogenic as well as natural sources. Mobile sources are excluded. The quantities as well as the main components are listed, as far as possible. The values given exclude methane which according to the present understanding is regarded as unreactive

Volatile flavours in raw egg yolk of hens fed on different diets.

Science.gov (United States)

Plagemann, Ina; Zelena, Kateryna; Krings, Ulrich; Berger, Ralf G

2011-08-30

Recent studies have suggested that the composition of lipophilic components of egg yolk is influenced by the feed. The aim of the present study was to isolate volatile flavours from egg yolk after different feeding trials using solvent extraction and thin layer high-vacuum distillation. The resulting aroma extract was analysed by various gas chromatographic techniques. Chickens were either fed with laying meal, laying meal plus cabbage and onion or laying meal plus rapeseed oil or held in free-range. The predominating odour impressions were described as onion-like. Comparing all analytical and sensory data of the flavour extracts, there were minimal differences among the respective samples. Free-range eggs contained fewer volatile compounds than the other samples, whereas rapeseed oil supplementation caused an enrichment of sulfur compounds. While data from gas chromatography/flame ionisation detection, gas chromatography/mass spectrometry and gas chromatography/olfactometry were less conclusive, the results from sulfur-specific analysis using gas chromatography/flame photometric detection showed a considerable effect. However, because of the low abundance of sulfur compounds in the yolk, these differences are not expected to be perceivable by the consumer. Copyright © 2011 Society of Chemical Industry.

Sulfur metabolism in phototrophic sulfur bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Dahl, Christiane

2008-01-01

Phototrophic sulfur bacteria are characterized by oxidizing various inorganic sulfur compounds for use as electron donors in carbon dioxide fixation during anoxygenic photosynthetic growth. These bacteria are divided into the purple sulfur bacteria (PSB) and the green sulfur bacteria (GSB......). They utilize various combinations of sulfide, elemental sulfur, and thiosulfate and sometimes also ferrous iron and hydrogen as electron donors. This review focuses on the dissimilatory and assimilatory metabolism of inorganic sulfur compounds in these bacteria and also briefly discusses these metabolisms...... in other types of anoxygenic phototrophic bacteria. The biochemistry and genetics of sulfur compound oxidation in PSB and GSB are described in detail. A variety of enzymes catalyzing sulfur oxidation reactions have been isolated from GSB and PSB (especially Allochromatium vinosum, a representative...

A process for producing lignin and volatile compounds from hydrolysis liquor.

Science.gov (United States)

Khazraie, Tooran; Zhang, Yiqian; Tarasov, Dmitry; Gao, Weijue; Price, Jacquelyn; DeMartini, Nikolai; Hupa, Leena; Fatehi, Pedram

2017-01-01

Hot water hydrolysis process is commercially applied for treating wood chips prior to pulping or wood pellet production, while it produces hydrolysis liquor as a by-product. Since the hydrolysis liquor is dilute, the production of value-added materials from it would be challenging. In this study, acidification was proposed as a viable method to extract (1) furfural and acetic acid from hot water hydrolysis liquor and (2) lignin compounds from the liquor. The thermal properties of the precipitates made from the acidification of hydrolysis liquor confirmed the volatile characteristics of precipitates. Membrane dialysis was effective in removing inorganic salts associated with lignin compounds. The purified lignin compounds had a glass transition temperature (Tg) of 180-190 °C, and were thermally stable. The results confirmed that lignin compounds present in hot water hydrolysis liquor had different characteristics. The acidification of hydrolysis liquor primarily removed the volatile compounds from hydrolysis liquor. Based on these results, a process for producing purified lignin and precipitates of volatile compounds was proposed.

Characterization of Volatile Compounds of Bulgur (Antep Type Produced from Durum Wheat

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Saad Ibrahim Yousif

2018-01-01

Full Text Available Bulgur is enjoyed and rediscovered by many people as a stable food because of its color, flavor, aroma, texture, and nutritional and economical values. There is more than one type of bulgur overall the world according to production techniques and raw materials. The volatile compounds of bulgur have not been explored yet. In this study, Headspace Solid Phase Microextraction (HS-SPME and Gas Chromatography–Mass Spectroscopy (GS-MS methods were used to determine the volatile flavor compounds of bulgur (Antep type, produced from Durum wheat. Approaching studies were used and the results were optimized to determine the ideal conditions for the extraction and distinguish the compounds responsible for the flavor of bulgur. Approximately, 47 and 37 important volatile compounds were determined for Durum wheat and bulgur, respectively. The study showed that there was a great diversity of volatiles in bulgur produced using Durum wheat and Antep type production method. These can lead to a better understanding of the combination of compounds that give a unique flavor with more researches.

Induction of conidiation by endogenous volatile compounds in Trichoderma spp.

Science.gov (United States)

Nemcovic, Marek; Jakubíková, Lucia; Víden, Ivan; Farkas, Vladimír

2008-07-01

Light and starvation are two principal environmental stimuli inducing conidiation in the soil micromycete Trichoderma spp. We observed that volatiles produced by conidiating colonies of Trichoderma spp. elicited conidiation in colonies that had not been induced previously by exposure to light. The inducing effect of volatiles was both intra- and interspecific. Chemical profiles of the volatile organic compounds (VOCs) produced by the nonconidiated colonies grown in the dark and by the conidiating colonies were compared using solid-phase microextraction of headspace samples followed by tandem GC-MS. The conidiation was accompanied by increased production of eight-carbon compounds 1-octen-3-ol and its analogs 3-octanol and 3-octanone. When vapors of these compounds were applied individually to dark-grown colonies, they elicited their conidiation already at submicromolar concentrations. It is concluded that the eight-carbon VOCs act as signaling molecules regulating development and mediating intercolony communication in Trichoderma.

Production of fungal volatile organic compounds in bedding materials

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S. LAPPALAINEN

2008-12-01

Full Text Available The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin and analysed by gas chromatography. Several microbial volatile organic compounds (MVOCs, e.g. 1-butanol, 2-hexanone, 2-heptanone, 3-octanone, 1-octen-3-ol and 1-octanol were detected in laboratory experiments; however, these accounted for only 0.08-1.5% of total volatile organic com-pounds (TVOCs. Emission rates of MVOCs were 0.001-0.176 mg/kg of bedding materials per hour. Despite some limitations of the analytical method, certain individual MVOCs, 2-hexanone, 2-hep-tanone and 3-octanone, were also detected in concentrations of less than 4.6 mg/m 3 (0.07-0.31% of TVOC in a horse stable where peat and shavings were used as bedding materials. MVOC emission rate was estimated to be 0.2-2.0 mg/kg ´ h -1 from bedding materials in the stable, being about ten times higher than the rates found in the laboratory experiments. Some compounds, e.g. 3-octanone and 1-octen-3-ol, can be assumed to originate mainly from microbial metabolisms.;

Headspace Analysis of Volatile Compounds Coupled to Chemometrics in Leaves from the Magnoliaceae Family

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Mohamed A. Farag

2015-01-01

Full Text Available Headspace volatile analysis has been used for volatiles profiling in leaves of 4 Magnolia species with a total of 75 compounds were identified. Monterpene hydrocarbons dominated the volatile blend of M. calophylla (86%, M. acuminata (78%, M. virginiana (70% and M. grandiflora (47% with b -pinene and b -ocimene occurring in the largest amounts, whereas sesquiterpenes were the most abundant compounds in M. grandiflora (39%. High levels of oxygenated compounds were only found in M. virginiana volatile blend (11.4% with 2-phenylethyl alcohol as major component. Hierarchical cluster analysis performed on volatiles content revealed the close relationship between M. acuminata and M. calophylla.

Analysis of volatile compounds by open-air ionization mass spectrometry.

Science.gov (United States)

Meher, Anil Kumar; Chen, Yu-Chie

2017-05-08

This study demonstrates a simple method for rapid and in situ identification of volatile and endogenous compounds in culinary spice samples through mass spectrometry (MS). This method only requires a holder for solid spice sample (2-3 mm) that is placed close to a mass spectrometer inlet, which is applied with a high voltage. Volatile species responsible for the aroma of the spice samples can be readily detected by the mass spectrometer. Sample pretreatment is not required prior to MS analysis, and no solvent was used during MS analysis. The high voltage applied to the inlet of the mass spectrometer induces the ionization of volatile compounds released from the solid spice samples. Furthermore, moisture in the air also contributes to the ionization of volatile compounds. Dried spices including cinnamon and cloves are used as the model sample to demonstrate this straightforward MS analysis, which can be completed within few seconds. Furthermore, we also demonstrate the suitability of the current method for rapid screening of cinnamon quality through detection of the presence of a hepatotoxic agent, i.e. coumarin. Copyright © 2017 Elsevier B.V. All rights reserved.

Recovery of wine volatile compounds during the vinification

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Encarnación Gómez-Plaza

1993-09-01

Full Text Available During the fermentation of grape sugars there is a formation of CO2, which escapes along with other volatile compounds being formed during the fermentation. To determine these lost main compounds, we placed an experimental system in a winery, which consisted in a cold trap connected to the exit of the fermentation tanks.

Composition of volatile aromatic compounds and minerals of tarhana enriched with cherry laurel (Laurocerasus officinalis).

Science.gov (United States)

Temiz, Hasan; Tarakçı, Zekai

2017-03-01

Different concentrations of cherry laurel pulp (0, 5, 10, 15 and 20%) were used to produce tarhana samples. Volatile aromatic compounds and minor mineral content were investigated. Volatile aromatic compounds were analyzed by using GC-MS with SPME fiber and minor mineral values were evaluated with inductively coupled plasma optical emission spectrometer. The statistical analysis showed that addition of pulp affected volatile aromatic compounds and minor mineral content significantly. Thirty five volatile aromatic compounds were found in tarhana samples. The octanoic acid from acids, benzaldehyde (CAS) phenylmethanal from aldehydes, 6-methyl-5-hepten-2-one from ketones, octadecane (CAS) n -octadecane form terpenes, ethyl caprylate from esters and benzenemethanol (CAS) benzyl alcohol from alcohols had the highest percentage of volatile aromatic compounds. Tarhana samples were rich source of Mn, Cu and Fe content.

Characterization and extraction of volatile compounds from pineapple (Ananas comosus L. Merril processing residues

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Lília Calheiros de Oliveira Barretto

2013-12-01

Full Text Available The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%, followed by ketones (26%, alcohols (18%, aldehydes (9%, acids (3% and other compounds (9%. Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.

Characterization of volatile aroma compounds in different brewing barley cultivars.

Science.gov (United States)

Dong, Liang; Hou, Yingmin; Li, Feng; Piao, Yongzhe; Zhang, Xiao; Zhang, Xiaoyu; Li, Cheng; Zhao, Changxin

2015-03-30

Beer is a popular alcoholic malt beverage resulting from fermentation of the aqueous extract of malted barley with hops. The aroma of brewing barley impacts the flavor of beer indirectly, because some flavor compounds or their precursors in beer come from the barley. The objectives of this research were to study volatile profiles and to characterize odor-active compounds of brewing barley in order to determine the variability of the aroma composition among different brewing barley cultivars. Forty-one volatiles comprising aldehydes, ketones, alcohols, organic acids, aromatic compounds and furans were identified using solid phase microextraction combined with gas chromatography/mass spectrometry, among which aldehydes, alcohols and ketones were quantitatively in greatest abundance. Quantitative measurements performed by means of solvent extraction and calculation of odor activity values revealed that acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2-methylbutanal, hexanal, heptanal, octanal, nonanal, 3-methyl-1-butanol, cyclopentanol, 2,3-butanedione, 2,3-pentanedione, 2-heptanone, acetic acid, ethyl acetate, 2-pentylfuran and benzeneacetaldehyde, whose concentrations exceeded their odor thresholds, could be considered as odor-active compounds of brewing barley. Principal component analysis was employed to evaluate the differences among cultivars. The results demonstrated that the volatile profile based on the concentrations of aroma compounds enabled good differentiation of most barley cultivars. © 2014 Society of Chemical Industry.

Determination of Volatile Organic Compounds in Selected Strains of Cyanobacteria

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Ivan Milovanović

2015-01-01

Full Text Available Microalgal biomass can be used in creating various functional food and feed products, but certain species of microalgae and cyanobacteria are known to produce various compounds causing off-flavour. In this work, we investigated selected cyanobacterial strains of Spirulina, Anabaena, and Nostoc genera originating from Serbia, with the aim of determining the chemical profile of volatile organic compounds produced by these organisms. Additionally, the influence of nitrogen level during growth on the production of volatile compounds was investigated for Nostoc and Anabaena strains. In addition, multivariate techniques, namely, principal component analysis (PCA and hierarchical cluster analysis (HCA, were used for making distinction among different microalgal strains. The results show that the main volatile compounds in these species are medium chain length alkanes, but other odorous compounds such as 2-methylisoborneol (0.51–4.48%, 2-pentylfuran (0.72–8.98%, β-cyclocitral (0.00–1.17%, and β-ionone (1.15–2.72% were also detected in the samples. Addition of nitrogen to growth medium was shown to negatively affect the production of 2-methylisoborneol, while geosmin was not detected in any of the analyzed samples, which indicates that the manipulation of growth conditions may be useful in reducing levels of some unwanted odor-causing components.

Synthesis and Odor Evaluation of Five New Sulfur-Containing Ester Flavor Compounds from 4-Ethyloctanoic Acid

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Baoguo Sun

2010-07-01

Full Text Available Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthiopropyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

Synthesis and odor evaluation of five new sulfur-containing ester flavor compounds from 4-ethyloctanoic acid.

Science.gov (United States)

Liu, Yuping; Chen, Haitao; Yin, Decai; Sun, Baoguo

2010-07-29

Five sulfur-containing flavor compounds were synthesized for the first time by the reaction of 4-ethyloctanoyl chloride with sulfur-containing alcohols or mercaptans. The synthesized compounds are 3-(methylthio)propyl 4-ethyloctanoate, 2-methyl-3-tetrahydro-furanthiol 4-ethyloctanoate, 4-methyl-5-thiazoleethanol 4-ethyloctanoate, 2-furan-methanethiol 4-ethyloctanoate and 2-methyl-3-furanthiol 4-ethyloctanoate. These five synthetic sulfur-containing ester flavor compounds all have meaty odor and might be used in foods if approved for this purpose in the future.

Online air analysis of reduced sulfur compounds at a swine facility

Science.gov (United States)

Reduced sulfur compounds are emitted from waste management handling and can be important in odor production and atmospheric chemistry. Data on the emissions of these compounds have been obtained using off-line sampling and analysis methods, but on-line methods providing information on temporal chang...

Volatile composition and sensory profile of shiitake mushrooms as affected by drying method.

Science.gov (United States)

Politowicz, Joanna; Lech, Krzysztof; Lipan, Leontina; Figiel, Adam; Carbonell-Barrachina, Ángel A

2018-03-01

One of the best preservation method for long-term storage is drying. In this work, the influence of different drying methods on aroma and sensory profile of shiitake mushroom was evaluated. The drying methods tested were: convective drying (CD), freeze-drying (FD), vacuum-microwave drying (VMD), and a combination of convective pre-drying and vacuum-microwave finish-drying (CPD-VMFD). The volatile composition of fresh and dried shiitake mushrooms was analysed by SPME, GC-MS and GC-FID, and showed the presence of 71 volatile compounds, most of them present in all dried samples but with quantitative variation. The major volatile compounds in fresh shiitake were 1-octen-3-ol (20.2%), 2-octanone (20.7%), 1,2,4-trithiolane (9.8%), and 1,2,3,5,6-pentathiepane (8.2%). Drying of shiitake mushrooms caused significant losses of C8 compounds and cyclic sulfur compounds, such as 1,2,4-trithiolane (V31) and 1,2,4,5-tetrathiane (V57). Samples dried at CD 80 °C implied a relative short drying time (120 min), had the highest contents of total volatiles (1594 μg 100 g -1 ) and cyclic sulfur compounds (e.g. V57 126 μg 100 g -1 ), and the highest intensity of most of the key positive sensory attributes, such as inner colour (7.0), fresh shiitake flavour (6.7), and sponginess (6.2). The best dehydration methods, resulting in the highest total concentrations of volatile compounds and high intensity of key sensory attributes were FD (if vacuum and liquid nitrogen facilities are available) and CD at 80 °C (for companies with vacuum and liquid nitrogen facilities). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

[Analysis of volatile sulfur compounds production of oral cavity in preschool children and influencing factors].

Science.gov (United States)

Zhang, Qun; Liu, Xue-nan; Chang, Qing; Ao, Shuang; Zheng, Shu-guo; Xu, Tao

2015-12-18

To investigate the prevalence of volatile sulfur compounds(VSC) in oral cavity of preschool children, and to analyze related factors, thus to provide scientific basis for the prediction and treatment of halitosis. The VSC content (hydrogen sulfide, methyl mercaptan, dimethyl sulfide) of 170 preschool children (4 to 6 years old) was detected by a portable gas chromatograph OralChromaTM. The status of the oral health was evaluated. The living habits and other aspects were obtained through questionnaires from the children's parents. A soft package for social statistics version 13.0 (SPSS 13.0) was used in which univariate analysis and multivariate analysis were utilized to analyze the related factors of halitosis in children. In the study, 34.4% of the total subjects had excessive VSC. Hydrogen sulfide (H₂S) [(1.59 ± 2.41) ng/10 mL] and total VSC concentration [(2.14 ± 4.42) ng/10 mL] in the girls were significantly higher (P<0.05) than those in the boys. The tongue coating score had a significant positive correlation with H2S [tongue coating area (1.68 ± 2.48) ng/10 mL,tongue coating thickness (2.18 ± 2.69) ng/10 mL] and total VSC concentration [tongue coating area, (2.26 ± 4.31) ng/10 mL,tongue coating thickness (2.41 ± 3.02) ng/10 mL , P<0.01]. The site number of DI-S ≥ 2 had a significant positive correlation with methyl mercaptan (CH3SH) and dimethyl sulfide [(CH3)2S] concentration (P<0.01). The concentration of H₂S [(1.19 ± 1.62) ng/10 mL] in children, whose mother had a higher degree of education, was statistically lower (P<0.01). The children who took dessert or sweat drinks more frequently had lower H2S [(1.04 ± 1.55) ng/10 mL, P<0.05] concentration, while CH3SH and (CH3₂)S concentration [(0.29 ± 1.92) ng/10 mL, (0.37 ± 2.06) ng/10 mL, P<0.05) were higher in the children with mouth-breath habit. A high prevalence of halitosis was noted in preschool children. Gender, tongue coating index, debris index-simplified, status of the mother

Volatile organic compound emissions from Larrea tridentata (creosotebush

Directory of Open Access Journals (Sweden)

A. Guenther

2010-12-01

Full Text Available We present results from the CREosote ATmosphere Interactions through Volatile Emissions (CREATIVE 2009 field study in southern Arizona aimed at quantifying emission rates of VOCs from creosotebush (Larrea tridentata during the summer 2009 monsoon season. This species was chosen because of its vast distribution in North and South American deserts and because its resins have been reported to contain a rich set of volatile organic compounds (VOC. While a variety of ecosystems have been investigated for VOC emissions, deserts remain essentially unstudied, partially because of their low biomass densities and water limitations. However, during the North American monsoon, a pronounced increase in rainfall from an extremely dry June (80 mm occurs over large areas of the Sonoran desert in the southwestern United States and northwestern Mexico. We observed a strong diurnal pattern of branch emissions and ambient concentrations of an extensive suite of VOCs with maxima in early afternoon. These include VOCs typically observed in forest sites (oxygenated VOCs and volatile isoprenoids as well as a large number of other compounds, some of which have not been previously described from any plant including 1-chloro-2-methoxy-benzene and isobutyronitrile. Although generally considered to be derived from anthropogenic sources, we observed emissions of aromatic compounds including benzene, and a broad range of phenolics. Dimethyl sulfide emissions from creosotebush were higher than reported from any previously studied plant suggesting that terrestrial ecosystems should be reconsidered as an important source of this climatically important gas. We also present direct, primary emission measurements of isoprene and its apparent oxidation products methyl vinyl ketone, methacrolein, and 3-methyl furan (the later three compounds are typically assumed to form from secondary reactions within the atmosphere, as well as a group of compounds considered to be fatty acid

Metabolomic profiling of the purple sulfur bacterium Allochromatium vinosum during growth on different reduced sulfur compounds and malate

OpenAIRE

Weissgerber, Thomas; Watanabe, Mutsumi; Hoefgen, Rainer; Dahl, Christiane

2014-01-01

Environmental fluctuations require rapid adjustment of the physiology of bacteria. Anoxygenic phototrophic purple sulfur bacteria, like Allochromatium vinosum, thrive in environments that are characterized by steep gradients of important nutrients for these organisms, i.e., reduced sulfur compounds, light, oxygen and carbon sources. Changing conditions necessitate changes on every level of the underlying cellular and molecular network. Thus far, two global analyses of A. vinosum responses to ...

Volatile organic compounds and oxides of nitrogen. Further emission reductions

Energy Technology Data Exchange (ETDEWEB)

Froste, H [comp.

1997-12-31

This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

Volatile organic compounds and oxides of nitrogen. Further emission reductions

Energy Technology Data Exchange (ETDEWEB)

Froste, H. [comp.

1996-12-31

This report presents the current status in relation to achievement of the Swedish Environmental target set by Parliament to reduce emission of volatile organic compounds by 50 per cent between 1988 and 2000. It also instructed the Agency to formulate proposed measures to achieve a 50 per cent reduction of emission of nitrogen oxides between 1985 and 2005. The report presents an overall account of emission trends for volatile organic compounds (from all sectors) and nitrogen oxides (from the industry sector) and steps proposed to achieve further emission reductions. 43 refs

Contribution of sulfuric acid and oxidized organic compounds to particle formation and growth

Directory of Open Access Journals (Sweden)

F. Riccobono

2012-10-01

Full Text Available Lack of knowledge about the mechanisms underlying new particle formation and their subsequent growth is one of the main causes for the large uncertainty in estimating the radiative forcing of atmospheric aerosols in global models. We performed chamber experiments designed to study the contributions of sulfuric acid and organic vapors to the formation and early growth of nucleated particles. Distinct experiments in the presence of two different organic precursors (1,3,5-trimethylbenzene and α-pinene showed the ability of these compounds to reproduce the formation rates observed in the low troposphere. These results were obtained measuring the sulfuric acid concentrations with two chemical ionization mass spectrometers confirming the results of a previous study which modeled the sulfuric acid concentrations in presence of 1,3,5-trimethylbenzene.

New analysis methods were applied to the data collected with a condensation particle counter battery and a scanning mobility particle sizer, allowing the assessment of the size resolved growth rates of freshly nucleated particles. The effect of organic vapors on particle growth was investigated by means of the growth rate enhancement factor (Γ, defined as the ratio between the measured growth rate in the presence of α-pinene and the kinetically limited growth rate of the sulfuric acid and water system. The observed Γ values indicate that the growth is already dominated by organic compounds at particle diameters of 2 nm. Both the absolute growth rates and Γ showed a strong dependence on particle size, supporting the nano-Köhler theory. Moreover, the separation of the contributions from sulfuric acid and organic compounds to particle growth reveals that the organic contribution seems to be enhanced by the sulfuric acid concentration. Finally, the size resolved growth analysis indicates that both condensation of oxidized organic compounds and reactive uptake contribute to particle growth.

Volatile organic compounds

International Nuclear Information System (INIS)

Silseth, May Liss

1998-01-01

The goal is: Not more emission of volatile organic compounds (VOCs) than necessary. The items discussed in this presentation are the VOCs, how to calculate emission of VOCs, how to reduce or avoid them, and different recovery processes. The largest source of Norwegian emissions of non methane VOCs (NMVOCs) is offshore loading of raw petroleum. Emissions of VOCs should be reduced mainly for two reasons: (1) on sunny days NMVOCs may react with NOx to form ozon and smog close to the surface, (2) ozone and smog close to the surface may be harmful to plants and animals, and they are hazardous to human health. As for the calculation of VOC emissions, the VOCON project will release the calculation program HCGASS in 1999. This project is a cooperative project headed by SINTEF/Marintek

Chlorine and Sulfur Volatiles from in Situ Measurements of Martian Surface Materials

Science.gov (United States)

Clark, B. C.

2014-12-01

A sentinel discovery by the first in situ measurements on Mars was the high sulfur and chlorine content of global-wide soils. A variety of circumstantial evidence led to the conclusion that soil S is in the form of sulfate, and the Cl is probably chloride. An early hypothesis states that these volatiles are emitted as gases from magmas, and quickly react with dust, soil, and exposed rocks. Subsequent determination that SNC meteorites are also samples of the martian crust revealed a significantly higher S content, as sulfide, than terrestrial igneous rocks but substantially less than in soils. The ensuing wet chemical analyses by the high-latitude Phoenix mission discovered not only chloride but also perchlorate and possibly chlorate. MSL data now also implicate perchlorate at low latitudes. Gaseous interactions may have produced amorphous material on grain surfaces without forming stoichiometric salts. Yet, when exposed to liquid water, Phoenix samples released electrolytes, indicating that the soils have not been leached by rain or fresh groundwater. Sulfate occurrences at many locations on Mars, as well as some chloride enrichments, have now been discovered by remote sensing, Landed missions have discovered Cl-enrichments and ferric, Mg, Ca and more complex sulfates as duricrust, subsurface soil horizons, sandstone evaporites, and rock coatings - most of which cannot be detected from orbit. Salt-forming volatiles affect habitability wherever they are in physical contact: physicochemical parameters (ionic strength, freezing point, water activity); S is an essential element for terrestrial organisms; perchlorate is an oxidant which can degrade some organics but also can be utilized as an energy source; the entire valence range of S-compounds has been exploited by diverse microbiota on Earth. Whether such salt-induced conditions are "extremes" of habitability depends on the relative abundance of liquid H2O.

Analysis of volatile organic compounds of ‘Fuji’ apples following electron beam irradiation and storage

International Nuclear Information System (INIS)

Song, Hyun-Pa; Shim, Sung-Lye; Lee, Sun-Im; Kim, Dong-Ho; Kwon, Joong-Ho; Kim, Kyong-Su

2012-01-01

The volatile organic compounds of non-irradiated and electron-beam irradiated ‘Fuji’ apples (Malus domestica Borkh.) at 0, 0.5, and 1 kGy were isolated through simultaneous distillation extractions and analyzed using gas chromatograph–mass spectrometry. A total of 53 volatile organic compounds were characterized in 0 and 1 kGy irradiated samples, whereas two more compounds related to ketone and terpenoid group were identified in 0.5 kGy irradiated samples. The contents of volatile compounds were 24.33, 36.49, and 35.28 mg/kg in 0, 0.5, and 1 kGy irradiated samples, respectively. The major compounds identified were butanol, hexanal, [E]-2-hexenal, and hexanol in all samples. The relative content of alcohol increased after 30 days of storage in all samples, whereas that of aldehyde decreased. Although the contents of some volatile compounds were changed by electron-beam irradiation, the total yield and major flavor compounds of irradiated ‘Fuji’ apples were similar to, or even greater than, those of the control. Therefore, the application of e-beam irradiation if required for microbial decontamination of ‘Fuji’ apples is an acceptable method as it does not bring about any major quantitative changes of volatile organic compounds. - Highlights: ► We analyzed the volatile organic compounds of electron beam irradiated Fuji apples. ► The major compounds of samples were butanol, hexanal, [E]-2-hexenal, and hexanol. ► The contents of major flavor compounds of non-irradiated and irradiated samples were similar.

Characterization of volatile compounds in Fen-Daqu - a traditional Chinese liquor fermentation starter

NARCIS (Netherlands)

Van-Diep, L.; Zheng, X.; Chen, J.Y.; Han, B.Z.

2012-01-01

Fen-Daqu is a saccharifying agent and fermentation starter for the production of Chinese liquor Fen (alcoholic spirit) and Fen traditional vinegar. The volatile compounds produced at seven incubation steps were analysed by HS-SPME-GC-MS. A total of 83 major volatile compounds were identified,

Bioprocesses for the Removal of Volatile Sulfur Compounds from Gas Streams

NARCIS (Netherlands)

Janssen, A.J.H.; bosch, van den P.L.M.; Leerdam, van R.C.; Graaff, de C.M.

2013-01-01

This chapter describes the biological removal of sulphur compounds from gas streams. First, an overview is given of the toxicity of sulphur compounds to animals and humans whereafter biological and industrial formation routes for (organic) sulphur compounds are given. Microbial degradation routes of

Determination of oxygen in uranium compounds using sulfur monochloride

International Nuclear Information System (INIS)

Baudin, G.; Besson, J.; Blum, P.L.; Tran-Van, Danh

1964-01-01

The authors have described in an other paper (Anal. Chim. Acta, in press) a method for oxygen determination in uranium compounds, in which the sample is attacked by sulfur monochloride. The present paper is concerned with the experimental aspects of the method: apparatus procedure. (authors) [fr

Development of an Analytic Method for Sulfur Compounds in Aged Garlic Extract with the Use of a Postcolumn High Performance Liquid Chromatography Method with Sulfur-Specific Detection.

Science.gov (United States)

Matsutomo, Toshiaki; Kodera, Yukihiro

2016-02-01

Garlic and its processed preparations contain numerous sulfur compounds that are difficult to analyze in a single run using HPLC. The aim of this study was to develop a rapid and convenient sulfur-specific HPLC method to analyze sulfur compounds in aged garlic extract (AGE). We modified a conventional postcolumn HPLC method by employing a hexaiodoplatinate reagent. Identification and structural analysis of sulfur compounds were conducted by LC-mass spectrometry (LC-MS) and nuclear magnetic resonance. The production mechanisms of cis-S-1-propenylcysteine (cis-S1PC) and S-allylmercaptocysteine (SAMC) were examined by model reactions. Our method has the following advantages: less interference from nonsulfur compounds, high sensitivity, good correlation coefficients (r > 0.98), and high resolution that can separate >20 sulfur compounds, including several isomers, in garlic preparations in a single run. This method was adapted for LC-MS analysis. We identified cis-S1PC and γ-glutamyl-S-allyl-mercaptocysteine in AGE. The results of model reactions suggest that cis-S1PC is produced from trans-S1PC through an isomerization reaction and that SAMC is produced by a reaction involving S-allylcysteine/S1PC and diallyldisulfide during the aging period. We developed a rapid postcolumn HPLC method for both qualitative and quantitative analyses of sulfur compounds, and this method helped elucidate a potential mechanism of cis-S1PC and SAMC action in AGE. © 2016 American Society for Nutrition.

Measurements of volatile compound contents in resins using a moisture analyzer.

Science.gov (United States)

Hashimoto, Masanori; Nagano, Futami; Endo, Kazuhiko; Ohno, Hiroki

2010-02-01

The contents of volatile adhesive compounds, such as water, solvents, and residual unpolymerized monomers, affect the integrity and durability of adhesive bonding. However, there is no method available that can be used to rapidly assess the residual solvent or water contents of adhesive resins. This study examined the effectiveness of a digital moisture analyzer to measure the volatile compound contents of resins. Five self-etching adhesives and seven experimental light-cured resins prepared with different contents (0, 10, and 20% by weight) of water or solvents (acetone and ethanol) were examined in this study. The resins were prepared using different methods (with and without air blast or light-curing) to simulate the clinical conditions of adhesive application. Resin weight changes (% of weight loss) were determined as the residual volatile compound contents, using the moisture analyzer. After the measurements, the resin films were examined using a scanning electron microscope. The weight changes of the resins were found to depend on the amount of water or solvents evaporating from the resin. Water and solvents were evaporated by air blast or light-curing, but some of the water and solvents remained in the cured resin. The moisture analyzer is easy to operate and is a useful instrument for using to measure the residual volatile compound contents of adhesive resin.

Data on volatile compounds in fermented materials used for salmon fish sauce production.

Science.gov (United States)

Nakano, Mitsutoshi; Sagane, Yoshimasa; Koizumi, Ryosuke; Nakazawa, Yozo; Yamazaki, Masao; Watanabe, Toshihiro; Takano, Katsumi; Sato, Hiroaki

2018-02-01

This article describes the analysis of volatile compounds in fermented materials used for salmon fish sauce production via gas chromatography/mass spectrometry (GC/MS). Ten types of fish sauces were produced from raw salmon materials, including various proportions of flesh, viscera, inedible portion (heads, fins, and backbones), and soft roe, by mixing them with salt and allowing them to ferment for up to three months. The volatile compounds were captured by a solid-phase microextraction method and then applied to GC/MS for separation and identification of the compounds in the fish sauce products. The number of volatile compounds identified in the starting materials varied from 15 to 29 depending on the ingredients. The number of compounds in the final fish sauce products was reduced by 3.4-94.7% of that in the original material. The retention times and names of the identified compounds, as well as their relative peak areas, are provided in a Microsoft Excel Worksheet.

HS-SPME analysis of volatile organic compounds of coniferous needle litter

Science.gov (United States)

Isidorov, V. A.; Vinogorova, V. T.; Rafałowski, K.

The composition of volatile emission of Scots pine ( Pinus sylvestris) and spruce ( Picea exelsa) litter was studied by gas chromatography-mass spectrometry (GC-MS) and samples were collected by solid-phase microextraction (SPME) method. The list of identified compounds includes over 60 organic substances of different classes. It was established that volatile emission contain not only components of essential oils of pine and spruce needles but also a large number of organic compounds which are probably secondary metabolites of litter-decomposing fungi. They include lower carbonyl compounds and alcohols as well as products of terpene dehydration and oxidation. These data show that the processes of litter decomposition are an important source of reactive organic compounds under canopy of coniferous forests.

Volatile organic compound (VOC) determination in working atmospheres; Determinacion de compuestos organicos volatiles (VOC) en ambiente laboral

Energy Technology Data Exchange (ETDEWEB)

Blass A, Georgina; Panama T, Luz A; Corrales C, Deyanira [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2003-07-01

The present work describes, in a synthesized way, the implementation and application of procedures based on the normativity related to the subject of the volatile organic compounds (Volatile Organic Compounds VOC), that allow to sample, quantify and evaluate the present contamination in the working atmosphere of a refinery due to the fugitive emissions of VOC and other substances. In accordance with the corresponding normativity, more than 189 organic compounds denominated dangerous air polluting agents (Hazardous Air Pollutants, HAP) can be found in a working atmosphere, but they are the 11 main HAP that can be found in a refinery. In the present article the work made for the sampling and quantification of 5 of the 11 dangerous polluting agents of the air: benzene, toluene, xylene, iso-octane and naphthalene. [Spanish] El presente trabajo describe, de manera sintetizada, la implementacion y aplicacion de procedimientos basados en la normatividad relacionada al tema de los compuestos organicos volatiles (Volatil Organic Compounds, VOC), que permiten muestrear, cuantificar y evaluar la contaminacion presente en el ambiente laboral de una refineria debido a las emisiones fugitivas de VOC y otras sustancias. De acuerdo con la normatividad correspondiente, mas de 189 compuestos organicos denominados contaminantes peligrosos del aire (Hazardous Air Pollutants, HAP), pueden ser encontrados en un ambiente laboral, pero son 11 los principales HAP que pueden ser hallados en una refineria. En el presente articulo se informa el trabajo realizado para el muestreo y cuantificacion de 5 de los 11 contaminantes peligrosos del aire: benceno, tolueno, xileno, iso-octano y naftaleno.

Effect of sugars on liquid-vapour partition of volatile compounds in ready-to-drink coffee beverages.

Science.gov (United States)

Piccone, P; Lonzarich, V; Navarini, L; Fusella, G; Pittia, P

2012-09-01

The effect of sugars (sucrose, lactose, glucose, fructose, 10%w/v) on the liquid-vapour partition of selected volatile compounds of coffee beverages has been investigated in espresso coffee and ready-to-drink (RTD) canned coffee prepared and obtained by using the same Arabica roasted coffee beans blend. Aroma composition of coffee beverages has been preliminary investigated by headspace-gas chromatography (HS-GC) and solid phase microextraction-HS-GC-mass spectrometry to characterize the volatile pattern of the systems and to evaluate the effects of sugars on the aroma release/retention. Then, the liquid-vapour partition coefficient (k) of 4 selected key aroma compounds (diacetyl, 2,3-pentanedione, ethylpyrazine, hexanal) was determined in water, sugars solutions as well as RTD coffee brews added with the same sugars (10%w/v). Sugars added in coffee beverages affected the release of the volatiles and thus its aroma profile with differences due to the type of added sugar and coffee brew type. The k values of the selected volatile compounds resulted different depending on the model system composition (water, coffee brew) and sugar type added. In particular, melanoidins as well as other non-volatile components (lipids, acids, carbohydrates) in the RTD coffee brews could be implied in the change of k of the volatile compounds in respect to that observed in water. The effects of the sugar type on the release/retention of the four key coffee aroma compounds were partly explained in terms of 'salting out' especially for the more polar volatile compounds and in the sucrose-added model systems. The change of chemical and physico-chemical properties of the water and brews induced by the sugars as well as the occurrence of interactions between volatile compounds and non-volatile components may be implied in the reduction of the vapour partition of the aroma compounds. Copyright © 2012 John Wiley & Sons, Ltd.

Thermochemical Sulfate Reduction Simulation Experiments on the Formation and Distribution of Organic Sulfur Compounds in the Tuha Crude Oil

Energy Technology Data Exchange (ETDEWEB)

Yue, Changtao; Li, Shuyuan [China Univ. of Petroleum, Beijing (China); Song, He [Research Institute of Petroleum Engineering of CNPC, Tianjin (China)

2014-07-15

Thermochemical sulfate reduction (TSR) was conducted in autoclave on the system of crude oil and MgSO{sub 4} at different temperatures. Gas chromatography pulsed flame photometric detector (GC-PFPD) was used to detected the composition of organic sulfur compounds in oil phase products. The results of the analysis indicate that with increased temperature, the contents of organic sulfur compounds with high molecular weight and thermal stability, such as benzothiophenes and dibenzothiophenes, gradually became dominated. In order to gain greater insight into the formation and distribution of organic sulphur compounds from TSR, positive ion electrospray Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used in detecting the detailed elemental composition and distribution of them. The mass spectra showed that the mass range of sulfur compounds was 200-550 Da. Four sulfur class species, S{sub 1}, N{sub 1}S{sub 1}, O{sub 1}S{sub 1} and O{sub 2}S{sub 1}, were assigned in the positive-ion spectrum. Among the identified sulfur compounds, the S{sub 1} class species was dominant. The most abundant S{sub 1} class species increase associated with the DBE value and carbon number increasing which also indicates the evolution of organic sulfur compounds in TSR is from the labile series to the stable one. In pure blank pyrolysis experiments with crude oil cracking without TSR, different composition and distribution of organic sulfur compounds in oil phase products were seen from mass spectra in order to evaluate their pyrolysis behaviors without MgSO{sub 4}. FT-IR and XRD were used in analyzing the products of solid phases. Two distinct crystallographic phases MgO and MgSO{sub 4} are found to coexist in the products which demonstrated the transformation of inorganic sulfur compounds into organosulfur compounds exist in TSR.

Optimization of low sulfur jerusalem artichoke juice for fossil fuels biodesulfurization process

OpenAIRE

Silva, Tiago P.; Paixão, Susana M.; Roseiro, J. Carlos; Alves, Luís Manuel

2013-01-01

Most of the world’s energy is generated from the burning of fossil fuels such as oil and its derivatives. When burnt, these fuels release into the atmosphere volatile organic compounds, sulfur as sulfur dioxide (SO2) and the fine particulate matter of metal sulfates. These are pollutants which can be responsible for bronchial irritation, asthma attacks, cardio-pulmonary diseases and lung cancer mortality, and they also contribute for the occurrence of acid rains and the increase of the hole i...

Removal of volatile organic compounds by a high pressure microwave plasma torch

International Nuclear Information System (INIS)

Rubio, S.J.; Quintero, M.C.; Rodero, A.; Alvarez, R.

2004-01-01

A helium microwave plasma torch was studied and optimised as a destruction system of volatile organic compounds. Attention was focused on trichloroethylene as a prototypical volatile organic compound, which is used technologically and which poses known health risks. The dependence of the destruction efficiency on the plasma conditions was obtained for different values of trichloroethylene concentrations. The results show a destruction and removal efficiency greater than 99.999% (Authors)

Volatile Compounds and Lactic Acid Bacteria in Spontaneous Fermented Sourdough

International Nuclear Information System (INIS)

Kam, W.Y.; Aida, W.M.W.; Sahilah, A.M.; Maskat, M.Y.

2011-01-01

The aim of this study is to identify the predominating lactic acid bacteria (LAB) in a spontaneous fermented wheat sourdough. At the same time, an investigation towards volatile compounds that were produced was also carried out. Lactobacillus plantarum has been identified as the dominant species of lactobacilli with characters of a facultative heterofermentative strain. The generated volatile compounds that were produced during spontaneous fermentation were isolated by solvent extraction method, analysed by gas chromatography (GC), and identified by mass spectrophotometer (MS). Butyric acid has been found to be the main volatile compound with relative abundance of 6.75 % and acetic acid at relative abundance of 3.60 %. Esters that were formed at relatively low amount were butyl formate (1.23 %) and cis 3 hexenyl propionate (0.05 %). Butanol was also found at low amount with relative abundance of 0.60 %. The carbohydrate metabolism of Lactobacillus plantarum may contributed to the production of acetic acid in this study via further catabolism activity on lactic acid that was produced. However, butyric acid was not the major product via fermentation by LAB but mostly carried out by the genus Clostridium via carbohydrate metabolism which needs further investigation. (author)

DONKEY MILK SHELF LIFE: MICROBIOLOGY AND VOLATILE COMPOUNDS

Directory of Open Access Journals (Sweden)

F. Conte

2010-03-01

Full Text Available Organoleptics properties are important to evaluate the shelf life of food products. Sensory analysis is generally used for this purpose. In this study psychrotrophic, mesophilic bacteria, and pH values were correlated to volatile compounds. The quality of raw donkey milk stored for 3, 7, 10, 14 and 28 days at two different temperatures (3°C and 7°C was tested. Donkey milk volatiles for the first time in this study were identified. Different volatiles distribution were detected by Smart Nose and GCO during the trials and a correlation with bacteriological and pH data were shown. On the basis of the results the acceptability of 10 days storing at +3°C, and of 3-4 days at +7°C, for milk samples, was pointed out.

Graphene-supported zinc oxide solid-phase microextraction coating with enhanced selectivity and sensitivity for the determination of sulfur volatiles in Allium species.

Science.gov (United States)

Zhang, Suling; Du, Zhuo; Li, Gongke

2012-10-19

A graphene-supported zinc oxide (ZnO) solid-phase microextraction (SPME) fiber was prepared via a sol-gel approach. Graphite oxide (GO), with rich oxygen-containing groups, was selected as the starting material to anchor ZnO on its nucleation center. After being deoxidized by hydrazine, the Zn(OH)2/GO coating was dehydrated at high temperature to give the ZnO/graphene coating. Sol-gel technology could efficiently incorporate ZnO/graphene composites into the sol-gel network and provided strong chemical bonding between sol-gel polymeric SPME coating and silica fiber surface, which enhanced the durability of the fiber and allowed more than 200 replicate extractions. Results indicated that pure ZnO coated fiber did not show adsorption selectivity toward sulfur compounds, which might because the ZnO nanoparticles were enwrapped in the sol-gel network, and the strong coordination action between Zn ion and S ion was therefore blocked. The incorporation of graphene into ZnO based sol-gel network greatly enlarged the BET surface area from 1.2 m2/g to 169.4 m2/g and further increased the adsorption sites. Combining the superior properties of extraordinary surface area of graphene and the strong coordination action of ZnO to sulfur compounds, the ZnO/graphene SPME fiber showed much higher adsorption affinity to 1-octanethiol (enrichment factor, EF, 1087) than other aliphatic compounds without sulfur-containing groups (EFsPDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) SPME fibers. Several most abundant sulfur volatiles in Chinese chive and garlic sprout were analyzed using the ZnO/graphene SPME fiber in combination with gas chromatography-mass spectrometry (GC-MS). Their limits of detection were 0.1-0.7 μg/L. The relative standard deviation (RSD) using one fiber ranged from 3.6% to 9.1%. The fiber-to-fiber reproducibility for three parallel prepared fibers was 4.8-10.8%. The contents were in the range of 1.0-46.4 μg/g with recoveries of 80.1-91.6% for four main

Changes in Volatile Compounds of Chinese Luzhou-Flavor Liquor during the Fermentation and Distillation Process.

Science.gov (United States)

Ding, Xiaofei; Wu, Chongde; Huang, Jun; Zhou, Rongqing

2015-11-01

The aim of this study was to investigate the dynamic of volatile compounds in the Zaopei during the fermentation and distillation process by headspace solid-phase microextraction-gas chromatography mass spectrometry (HS-SPME-GCMS). Physicochemical properties analysis of Zaopei (fermented grains [FG], fermented grains mixed with sorghum [FGS], streamed grains [SG], and streamed grains mixed with Daqu [SGD]) showed distinct changes. A total number of 66 volatile compounds in the Zaopei were identified, in which butanoic acid, hexanoic acid, ethyl hexanoate, ethyl lactate, ethyl octanoate, hexyl hexanoate, ethyl hydrocinnamate, ethyl oleate, ethyl hexadecanoate, and ethyl linoleate were considered to be the dominant compounds due to their high concentrations. FG had the highest volatile compounds (112.43 mg/kg), which significantly decreased by 17.05% in the FGS, 67.12% in the SG, and 73.75% in the SGD. Furthermore, about 61.49% of volatile compounds of FGS were evaporated into raw liquor, whereas head, heart, and tail liquor accounted for 29.84%, 39.49%, and 30.67%, respectively. Each volatile class generally presented a decreasing trend, except for furans. Especially, the percentage of esters was 55.51% to 67.41% in the Zaopei, and reached 92.60% to 97.67% in the raw liquor. Principal component analysis based ordination of volatile compounds data segregated FGS and SGD samples. In addition, radar diagrams of the odor activity values suggested that intense flavor of fruit was weakened most from FG to SGD. The dynamic of volatile compounds in the Zaopei during the fermentation and distillation process was tested by SPME-GCMS. The result of this study demonstrated that both volatile compounds of Zaopei and thermal reaction during distillation simply determined the unique feature of raw liquor. This study was conducted based on the real products from liquor manufactory, so it is practicable that the method can be used in an industry setting. © 2015 Institute of Food

Effects of Methyl Jasmonate on the Composition of Volatile Compounds in Pyropia yezoensis

Science.gov (United States)

He, Lihong; Wang, Liang; Wang, Linfang; Shen, Songdong

2018-04-01

Volatile organic compounds in marine algae have been reported to comprise characteristic flavor of algae and play an important role in their growth, development and defensive response. Yet their biogeneration remain largely unknown. Here we studied the composition of volatile compouds in Pyropia yezoensis and their variations in response to methyl jasmonate (MeJA) and diethyldithiocarbamic acid (DIECA) treatment using gas chromatography-mass spectrometry (GC-MS). A total of 44 compounds belonging to the following chemical classes (n) were identified, including aldehydes (11), alcohols (8), acids and esters (6), alkanes (5), ketones (5), alkenes (3), and S- or N-containing miscellaneous compounds (6). External treatment with plant hormone MeJA increased the content of 1-dodecanol, 4-heptenal, and 2-propenoic acid-2-methyl dodecylester, but decreased the content of phytol, 3-heptadecene, 2-pentadecanone, and isophytol. When pretreated with DIECA, an inhibitor of the octadecanoid pathway leading to the biosynthesis of endogeneous jasmonates and some secondary metabolites, phytol and isophytol were increased, while 4-heptenal, 1-dodecanol, and 2-propenoic acid-2-methyl dodecylester were decreased, both of which were negatively correlated with their variations under MeJA treatment. Collectively, these results suggest that MeJA does affect the volatile composition of P. yezoensis, and the octadecanoid pathway together with endogenous jasmonate pathway may be involved in the biosynthesis of volatile compounds, thereby providing some preliminary envision on the composition and biogeneration of volatile compounds in P. yezoensis.

Determination of volatile aroma compounds of Ganoderma lucidum ...

African Journals Online (AJOL)

This study was conducted at Horticulture Department of Cukurova University, Adana, Turkey during 2010-2011. Fresh sample of Ganoderma lucidum collected from Mersin province of Turkey was used as material. Volatile aroma compounds were performed by Headspace Gas Chromatography (HS-GC/MS). Alcohols ...

Effect of volatile compounds on excimer laser power delivery.

Science.gov (United States)

Van Horn, Stewart D; Hovanesian, John A; Maloney, Robert K

2002-01-01

To determine whether vapors from perfume, hairspray, oil-based paint, or water-based paint affect excimer laser beam power delivery at the corneal surface. We measured the power delivery of an Apex Plus laser before, during, and after exposure to vapors from the following volatile compounds: three types of perfume, hair spray, an oil-based paint, and a water-based paint. A digital calorimeter was used to measure the steady-state beam power of the laser during laser discharge at the corneal plane. Multiple trials were run with each compound, and the change in laser energy over time was examined to determine if any of the compounds caused degradation of the laser optics. The presence of a volatile compound in the room caused no change in mean laser energy in comparison to before and after the compound was present. However, perfumes caused a progressive decline in laser beam power throughout the trials. Controlling for this progressive decline, there was no significant difference from perfume to perfume. None of the compounds tested caused a decline in laser beam power while present in the room. However, the presence of any perfume caused a deterioration in beam power over time, suggesting a degradation of the laser optics for all perfumes. Laser centers should consider advising their patients and staff to not wear perfumes in the laser suite.

Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

Science.gov (United States)

Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

2015-02-01

Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

Volatile Organic Compounds (VOCs) in the Ambient Air Of Concentration Unit of Sar-Cheshmeh Copper Complex

International Nuclear Information System (INIS)

Faghihi-Zrandi, A.; Akhgar, M. R.

2016-01-01

Air pollutants including gases, vapors and particles, are emitted from different sources. Volatile organic compounds are the most important pollutants in the ambient air of industries. The present study was carried out to identify and measurement of volatile organic compounds in concentration unit of Sar-Cheshmeh Copper Complex. In this study, sampling of the volatile organic compounds was done by using activated charcoal tube. To identify and measure these compounds gas chromatography/mass spectroscopy were used. Thirteen volatile organic compounds were identified in the ambient air of concentration unit. Among these compounds, the mean value and maximum concentration of isopropyl alcohol and nonane were 255, 640 μg/m3 and 1577, 14400 μg/m3, respectively. By using SPSS software and independent sample t- test, showed that there were no significant difference between mean value concentration of isopropyl alcohol and nonane in the ambient air and TLV values of these compounds (isopropyl alcohol; 200 ppm and nonane; 200 ppm) (P >0.05).

Production of fungal volatile organic compounds in bedding materials

OpenAIRE

S. LAPPALAINEN; A. PASANEN; P. PASANEN

2008-01-01

The high relative humidity of the air and many potential growth media, such as bedding materials, hay and grains in the horse stable, for example, provide suitable conditions for fungal growth. Metabolic activity of four common agricultural fungi incubated in peat and wood shavings at 25°C and 4°C was characterized in this study using previously specified volatile metabolites of micro-organisms and CO 2 production as indicators. The volatile organic compounds were collected into Tenax resin a...

Study on ionizing radiation effects in diesel and crude oil: organic compounds, hydrocarbon, sulfur and nitrogen

International Nuclear Information System (INIS)

Andrade, Luana dos Santos

2014-01-01

Petroleum is the most important energy and pollution source in the world, nowadays. New technologies in petrochemical industry aim to minimize energy spending at the process and to reduce pollution products. Sulfur and nitrogen compounds generate environmental problems; the most relevant is air pollution that affects the population health directly. The nuclear technology has been used in environmental protection through pollutants removal by free radicals produced at action of the radiation in water molecule. The objective of this study is to evaluate the radiation effects on oil and diesel, mainly in the hydrocarbons, organic sulfur, and nitrogen compounds. It was studied a molecule model of sulfur, named benzothiophene, diesel and crude oil samples. The samples were irradiated using a Co-60 source, Gammacell type. The total sulfur concentration in the samples was determined by X-ray fluorescence spectrometry, and organic compounds were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The study of molecular model showed that 95% was degraded at 20 kGy dose rate. Irradiation at 15 kGy of absorbed dose showed some cracking in petrol hydrocarbons, however with higher doses it was observed polymerization and low efficiency of cracking. It was observed that the sulfur compounds from diesel and petroleum was efficiently reduced. The applied doses of 15 kGy and 30 kGy were the most efficient on desulfurization of petroleum, and for diesel the highest variation was observed with 30 kGy and 50 kGy of absorbed dose. The distillation and chromatographic separation using an open column with palladium chloride as stationary phase showed a preferential separation of organic sulfur compounds in petroleum. (author)

Substitution of carcinogenic solvent dichloromethane for the extraction of volatile compounds in a fat-free model food system.

Science.gov (United States)

Cayot, Nathalie; Lafarge, Céline; Bou-Maroun, Elias; Cayot, Philippe

2016-07-22

Dichloromethane is known as a very efficient solvent, but, as other halogenated solvents, is recognized as a hazardous product (CMR substance). The objective of the present work is to propose substitution solvent for the extraction of volatile compounds. The most important physico-chemical parameters in the choice of an appropriate extraction solvent of volatile compounds are reviewed. Various solvents are selected on this basis and on their hazard characteristics. The selected solvents, safer than dichloromethane, are compared using the extraction efficiency of volatile compounds from a model food product able to interact with volatile compounds. Volatile compounds with different hydrophobicity are used. High extraction yields were positively correlated with high boiling points and high Log Kow values of volatile compounds. Mixtures of solvents such as azeotrope propan-2-one/cyclopentane, azeotrope ethyl acetate/ethanol, and mixture ethyl acetate/ethanol (3:1, v/v) gave higher extraction yields than those obtained with dichloromethane. Copyright © 2016 Elsevier B.V. All rights reserved.

ambient volatile organic compounds pollution and ozone formation

African Journals Online (AJOL)

OLUMAYEDE

2013-08-01

Aug 1, 2013 ... Volatile organic compound (VOC) species react at different rate and exhibit differences in reactivity with respect to ozone formation in polluted urban atmosphere. To assess this, the variations pattern, reactivity relative to OH radical and ozone creation potential of ambient VOCs were investigated in field.

Analysis of volatile organic compound from Elaeis guineensis inflorescences planted on different soil types in Malaysia

Science.gov (United States)

Muhamad Fahmi, M. H.; Ahmad Bukhary, A. K.; Norma, H.; Idris, A. B.

2016-11-01

The main attractant compound for Eleidobius kamerunicus to male spikelet Elaeis guineensis (oil palm) were determined by analyzing volatile organic compound extracted from E. guineenses inflorescences planted on different soil types namely peat soil, clay soil and sandy soil. Anthesizing male oil palm inflorescences were randomly choosen from palm aged between 4-5 years old age. Extraction of the volatiles from the oil palm inflorescences were performed by Accelerated Solvent Extraction method (ASE). The extracted volatile compound were determined by using gas chromatography-mass spectrometry. Out of ten identified compound, estragole was found to be a major compound in sandy soil (37.49%), clay soil (30.71%) and peat soil (27.79%). Other compound such as 9,12-octadecadieonic acid and n-hexadecanoic acid were found as major compound in peat soil (27.18%) and (7.45%); sandy soil (14.15 %) and (9.31%); and clay soil (30.23%) and (4.99%). This study shows that estragole was the predominant volatile compound detected in oil palm inflorescences with highly concentrated in palm planted in sandy soil type.

HS-SPME optimization and extraction of volatile compounds from soursop (Annona muricata L. pulp with emphasis on their characteristic impact compounds

Directory of Open Access Journals (Sweden)

Karen Leticia de SANTANA

Full Text Available Abstract Aroma and taste are decisive factors in the selection of any food. The aim of this study was to extract the volatile compounds present in soursop (Annona muricata L. pulp by Solid-phase microextraction (SPME technique using 3 different fibers (DVB/CAR/ PDMS, CAR/PDMS and PDMS/DVB. An experimental design was set up to evaluate the best extraction conditions wherein the variables were adsorption temperature, ionic strength and pulp concentration. The separation of volatiles was performed in chromatographic columns of different polarity (polar and non-polar while volatile compounds were identified by analysis in high resolution gas chromatography system coupled with mass spectrometry. The results obtained using 3 different fibers revealed the capture of about 40 compounds. The CAR/PDMS fiber was more efficient for the capture of esters and DVB/CAR/PDMS fiber for terpenes. The optimum conditions for capture of higher number of volatiles for polar column were 45 °C for extraction, 15% of ionic strength and 50% of pulp concentration which resulted in separation of 87 compounds. Among the principal character impact compounds from soursop are (E-2-hexenoate, methyl hexenoate and linalool.

Measurements of sulfur compounds in CO2 by diode laser atomic absorption spectrometry

International Nuclear Information System (INIS)

Franzke, J.; Stancu, D.G.; Niemax, K.

2003-01-01

Two simple methods for the analysis of the total concentration of sulfur in CO 2 by diode laser atomic absorption spectrometry of excited, metastable sulfur atoms in a direct current discharge are presented. In the first method, the CO 2 sample gas is mixed with the plasma gas (Ar or He) while the second is based on reproducible measurements of the sulfur released from the walls in a helium discharge after being deposited as a result of operating the discharge in pure CO 2 sample gas. The detection limits obtained satisfy the requirements for the control of sulfur compounds in CO 2 used in the food and beverage industry

Leaf Volatile Compounds and Associated Gene Expression during Short-Term Nitrogen Deficient Treatments in Cucumis Seedlings

Directory of Open Access Journals (Sweden)

Jie Deng

2016-11-01

Full Text Available Nitrogen (N is an important macronutrient for plant growth and development, but the regulatory mechanism of volatile compounds in response to N deficiency is not well understood, especially in cucumber, which consumes excessive N during growth. In this study, the major volatile compounds from cucumber leaves subjected to N deficiency were analyzed by GC-MS. A total of 24 volatile components were identified including 15 aldehydes, two ketones, two alkenes, and five other volatile compounds in 9930 leaves. Principal component analysis using volatile compounds from cucumber leaves provided good separation between N-sufficient and N-deficient treatments. The main volatiles in cucumber leaves were found to be C6 and C9 aldehydes, especially (E-2-hexanal and (E,Z-2,6-nonadienal. (E-2-hexanal belonged to the C6 aldehyde and was the most abundant compound, whereas (E,Z-2,6-nonadienal was the chief component of C9 aldehydes. During N-deficient treatment, short-chain volatile content was significantly improved at 5 day, other volatiles displayed significant reduction or no significantly changes in all sampling points. Improvement of short-chain volatiles was confirmed in the six other inbred lines at 5 day after N-deficient treatments. The expression analysis of 12 cucumber LOX genes and two HPL genes revealed that CsLOX19, CsLOX20, and CsLOX22 had common up-regulated expression patterns in response to N-deficient stress in most inbred lines; meanwhile, most sample points of CsHPL1 also had significant up-regulated expression patterns. This research focused on the relationship between volatiles in cucumber and different nitrogen environments to provide valuable insight into the effect of cultivation and management of the quality of cucumber and contributes to further research on volatile metabolism in cucumber.

Volatile aromatic compounds in Mexico City atmosphere: levels and source apportionment

Energy Technology Data Exchange (ETDEWEB)

Mugica, V. [Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D.F. (Mexico); Ruiz, M.E. [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Watson, J.; Chow, J. [Desert Research Institute, Reno, Nevada (United States)

2003-01-01

Samples of ambient air were simultaneously collected at three different sites of Mexico City in March of 1997 in order to quantify the most abundant volatile aromatic compounds and estimate the source contributions by application of the chemical mass balance model (CMB). Volatile aromatic compounds were around 20% of the total of non-methane hydrocarbons present in morning air samples. The most abundant volatile aromatic species in urban air were toluene and xylenes followed by 1, 2, 4 trimethylbenzene, benzene, ethylbenzene, metaethyltoluene, 1, 3, 5 trimethylbenzene, styrene, n propylbenzene, and isopropylbenzene. Sampling campaigns were carried out at crossroads, a bus station, a parking place, and areas where solvents and petroleum distillates are used, with the objective of determining people's exposure to volatile aromatic compounds. The CMB was applied for estimating the contribution of different sources to the presence of each one of the most abundant aromatic compounds. Motor vehicle exhaust was the main source of all aromatic compounds, especially gasoline exhaust, although diesel exhausts and asphalt operations also accounted for toluene, xylenes, ethylbenzene, propylbenzenes, and styrene. Graphic arts and paint applications had an important impact on the presence of toluene. [Spanish] Se colectaron simultaneamente muestras de aire ambiente en tres sitios de la Ciudad de Mexico durante el mes de marzo de 1997 con el fin de conocer las concentraciones y el origen de compuestos aromaticos utilizando el modelo de balance de masa de especies quimicas (CMB). Los compuestos aromaticos volatiles representaron alrededor del 20% del total de hidrocarburos no metalicos presentes en las muestras matutinas colectadas. Las especies aromaticas volatiles mas abundantes en el ambiente fueron el tolueno y los xilenos, seguidos por 1, 2, 4 trimetilbenceno, benceno, etilbenceno, metaetiltolueno, nporpilbenceno, isopropilbenceno, 1, 3, 5 trimetilbenceno y estireno. Se

Volatile organic compounds and Photobacterium phosphoreum associated with spoilage of modified-atmosphere-packaged raw pork

DEFF Research Database (Denmark)

Nieminen, Timo T.; Dalgaard, Paw; Björkroth, Johanna

2016-01-01

Accumulation of volatile organic compounds was monitored in association with sensory quality, bacterial concentrations and culture-independent microbial community analyses in raw pork loin and pork collar during storage under high-oxygen modified atmosphere at +4°C. Of the 48 volatile compounds...

Adsorption of Volatile Organic Compounds from Aqueous Solution by Granular Activated Carbon in Batch System

International Nuclear Information System (INIS)

Zeinali, F.; Ghoreyshi, A. A.; Najafpour, G.

2011-01-01

Chlorinated hydrocarbons and aromatics are the major volatile organic compounds that contaminate the ground water and industrial waste waters. The best way to overcome this problem is to recover the dissolved compounds in water. In order to evaluate the potential ability of granular activated carbon for recovery of volatile organic compounds from water, the equilibrium adsorption was investigated. This study deals with the adsorption of dichloromethane as a typical chlorinated volatile organic compound and toluene as the representative of aromatic volatile organic compounds on a commercial granular activated carbon. The adsorption isotherms of these two volatile organic compounds on granular activated carbon were measured at three different temperatures, toluene at 293, 303 and 313 K and dichloromethane at 298, 303 and 313 K within their solubility concentration range in water. The maximum adsorption capacity of dichloromethane and toluene adsorption by granular activated carbon was 4 and 0.2 mol/Kg-1, respectively. The experimental data obtained were correlated with different adsorption isotherm models. The Langmuir model was well adapted to the description of dichloromethane adsorption on granular activated carbon at all three temperatures, while the adsorption of toluene on granular activated carbon was found to be well described by the Langmuir-BET hybrid model at all three temperatures. The heat of adsorption was also calculated based on the thermodynamic equation of Clausius Clapeyron, which indicates the adsorption process is endothermic for both compounds.

Increase in volatilization of organic compounds using air sparging through addition in alcohol in a soil-water system.

Science.gov (United States)

Chao, Huan-Ping; Hsieh, Lin-Han Chiang; Tran, Hai Nguyen

2018-02-15

This study developed a novel method to promote the remediation efficiency of air sparging. According to the enhanced-volatilization theory presented in this study, selected alcohols added to groundwater can highly enhance the volatilization amounts of organic compounds with high Henry's law constants. In this study, the target organic compounds consisted of n-hexane, n-heptane, benzene, toluene, 1,1,2-trichloroethane, and tetrachloroethene. n-pentanol, n-hexanol, and n-heptanol were used to examine the changes in the volatilization amounts of organic compounds in the given period. Two types of soils with high and low organic matter were applied to evaluate the transport of organic compounds in the soil-water system. The volatilization amounts of the organic compounds increased with increasing alcohol concentrations. The volatilization amounts of the test organic compounds exhibited a decreasing order: n-heptanol>n-hexanol>n-pentanol. When 10mg/L n-heptanol was added to the system, the maximum volatilization enhancement rate was 18-fold higher than that in distilled water. Samples of soil with high organic matter might reduce the volatilization amounts by a factor of 5-10. In the present study, the optimal removal efficiency for aromatic compounds was approximately 98%. Copyright © 2017 Elsevier B.V. All rights reserved.

Ewe's diet (pasture vs grain-based feed) affects volatile profile of cooked meat from light lamb.

Science.gov (United States)

Almela, Elisabeth; Jordán, María José; Martínez, Cristina; Sotomayor, José Antonio; Bedia, Mario; Bañón, Sancho

2010-09-08

The effects of ewe's diet during gestation and lactation on the volatile compounds profile in cooked meat from light lamb were compared. Two lamb groups from ewes that had been fed pasture (PA) or grain-based concentrate (FE) were tested. Cooked loin mixed with saliva was analyzed by solid phase microextraction, gas chromatography, and mass spectrometry. The fiber coating used was divinylbenzene-carboxen-polydimethylsiloxane. The volatiles detected and quantified were aldehydes, alcohols, ketones, phenols, indole, and sulfur compounds. The ewe's diet strongly affected the volatile compounds profile of the cooked meat. The total volatiles concentration was higher in PA (409 mg kg(-1)) than in FE (201 mg kg(-1)). The major volatiles in PA were phenol, 4-methylphenol, and hexanoic acid, while the major volatile in FE was 3-hydroxy-2-butanone. No branched C8-C9 fatty acids responsible for mutton flavor were detected in either group. The findings suggest that nutritional strategies can be use during gestation and lactation to modify the aroma of light lamb meat in the light of consumer preferences.

Microlayer source of oxygenated volatile organic compounds in the summertime marine Arctic boundary layer

OpenAIRE

Mungall, Emma L.; Abbatt, Jonathan P. D.; Wentzell, Jeremy J. B.; Lee, Alex K. Y.; Thomas, Jennie L.; Blais, Marjolaine; Gosselin, Michel; Miller, Lisa A.; Papakyriakou, Tim; Willis, Megan D.; Liggio, John

2017-01-01

A biogeochemical connection between the atmosphere and the ocean is demonstrated whereby a marine source of oxygenated volatile organic compounds is identified. Compounds of this type are involved in the formation of secondary organic aerosol, which remains one of the most poorly understood components of Earth’s climate system due in part to the diverse sources of its volatile organic compound precursors. This is especially the case for marine environments, where there are more oxygenated vol...

Volatile Compounds in Dry Dog Foods and Their Influence on Sensory Aromatic Profile

Directory of Open Access Journals (Sweden)

Koushik Adhikari

2013-02-01

Full Text Available The aim of this study was to determine volatile compounds in dry dog foods and their possible influence on sensory aromatic profile. Grain-free dry dog foods were compared to dry dog foods manufactured with grain, but also with different protein sources for their aromatic volatiles. Solid-phase microextraction/gas chromatography/mass spectrometry was used to determine the aromatic compounds present in the headspace of these samples. Partial Least Squares regression was performed to correlate the instrumental aromatic data with the descriptive aroma analysis data. A total of 54 aromatic compounds were tentatively identified in the dry dog food samples, with aldehydes and ketones being the most represented organic volatiles group. Grain-added products were on the average higher in total volatiles than grain-free products. Partial Least Squares regression analysis indicated possible connections with sensory aromatic profile and grain-added samples, such as rancid aroma and aldehydes, especially hexanal. The results of this study showed that dry dog foods are products with complex odor characteristics and that grain-free products are less aromatic.

Manganese-Loaded Activated Carbon for the Removal of Organosulfur Compounds from High-Sulfur Diesel Fuels

OpenAIRE

Al-Ghouti, M.A.; Al-Degs, Y.S.

2014-01-01

The adsorptive capacity of activated carbon (AC) is significantly enhanced toward weakly interacting organosulfur compounds (OSC) from sulfur-rich diesel fuel. Sulfur compounds are selectively removed from diesel after surface modification by manganese dioxide (MnO2). A selective surface for OSC removal was created by loading MnO2 on the surface; π-complexation between the partially filled d-orbitals of Mn4+ and the S atom is the controlling mechanism for OSC removal. Principal component anal...

Synthesis and characterization of volatile technetium compound

International Nuclear Information System (INIS)

Childs, Bradley C.; Poineau, Frederic; Czerwinski, Ken R.

2013-01-01

Technetium-99 is an important fission (T 1/2 = 2.13.105 y) product of the nuclear industry. Technetium in its highest oxidation state (VII) is highly mobile and can represent a threat to the environment. There are over 55 million gallons of high level mixed waste located at the Hanford site. Waste tanks at the Hanford site contain Tc that could potentially leak, and in the context of management of technetium, a glass waste form was proposed to counteract the issue. In the process of synthesizing melt glass between the temperatures of 600°C and 1100°C, volatile technetium compounds were observed in the reaction tube. These compounds displayed characteristic colors based upon the reaction environments of either breathing air or nitrogen gas. A breathing air atmosphere produces a red compound that adheres to the walls of the reaction tube. An atmosphere of nitrogen gas produces a white compound that was observed on the walls of the reaction tube. (author)

Safety of food contact silicone rubber: Liberation of volatile compounds from soothers and teats

DEFF Research Database (Denmark)

Lund, Kirsten H.; Petersen, Jens Højslev

2002-01-01

The release of volatile compounds from soothers and teats made from silicone rubber has been investigated. Firstly, measurements of the total release of volatiles were performed according to the method in the draft European standard (CEN). Weight losses of 0.17-0.80% after four hours at 200 degrees......C were observed using gravimetric measurements. One product had a weight loss above the proposed CEN limit of 0.5%. Secondly, the volatile compounds were identified using a thermal desorption/cold trap injector on a gas chromatograph equipped with infrared spectroscopic (IR) and mass spectrometric (MS...

[Behavioral response of Anopheles albimanus to volatile compounds collected inside houses from the south of Chiapas, Mexico].

Science.gov (United States)

Ríos-Delgado, Silvany Mayoly; Rodríguez-Ramírez, Américo David; Cruz-López, Leopoldo; Escobar-Pérez, Luis Alonso; Aburto-Juárez, Ma de Lourdes; Torres-Estrada, José Luis

2008-01-01

To determine effects of volatile compounds in homes on the behavioral response of Anopheles albimanus. The study was conducted in January 2006, in the village of Nueva Independencia village, Suchiate, Chiapas. Volatile compounds were collected inside homes and the extracts were tested on unfed females in a Y-olfactometer. Extracts were analyzed in a gas chromatography-mass spectrometry system (GC-MS). Twenty eight extracts were obtained, twelve presented attraction and two repellency responses. GC-MS analyses of the extracts indicated variation in the volatile compound present in the extracts, but could not associated specific compounds with any particular effect. Within homes, volatiles presented attraction and repellency responses to An. albimanus. A definate pattern concerning the presence of a characteristic chemical compound and the observed response was not found.

Holographic detection of hydrocarbon gases and other volatile organic compounds.

Science.gov (United States)

Martínez-Hurtado, J L; Davidson, C A B; Blyth, J; Lowe, C R

2010-10-05

There is a need to develop sensors for real-time monitoring of volatile organic compounds (VOCs) and hydrocarbon gases in both external and indoor environments, since these compounds are of growing concern in human health and welfare. Current measurement technology for VOCs requires sophisticated equipment and lacks the prospect for rapid real-time monitoring. Holographic sensors can give a direct reading of the analyte concentration as a color change. We report a technique for recording holographic sensors by laser ablation of silver particles formed in situ by diffusion. This technique allows a readily available hydrophobic silicone elastomer to be transformed into an effective sensor for hydrocarbon gases and other volatile compounds. The intermolecular interactions present between the polymer and molecules are used to predict the sensor performance. The hydrophobicity of this material allows the sensor to operate without interference from water and other atmospheric gases and thus makes the sensor suitable for biomedical, industrial, or environmental analysis.

Characteristics of the volatile organic compounds -- Arid Integrated Demonstration Site

International Nuclear Information System (INIS)

Last, G.V.; Lenhard, R.J.; Bjornstad, B.N.; Evans, J.C.; Roberson, K.R.; Spane, F.A.; Amonette, J.E.; Rockhold, M.L.

1991-10-01

The Volatile Organic Compounds -- Arid Integrated Demonstration Program (VOC-Arid ID) is targeted at demonstration and testing of technologies for the evaluation and cleanup of volatile organic compounds and associated contaminants at arid DOE sites. The initial demonstration site is an area of carbon tetrachloride (CCl 4 ) contamination located near the center of the Hanford Site. The movement of CCl 4 and other volatile organic contaminants in the subsurface is very complex. The problem at the Hanford Site is further complicated by the concurrent discharge of other waste constituents including acids, lard oil, organic phosphates, and transuranic radionuclides. In addition, the subsurface environment is very complex, with large spatial variabilities in hydraulic properties. A thorough understanding of the problem is essential to the selection of appropriate containment, retrieval, and/or in situ remedial technologies. The effectiveness of remedial technologies depends on knowing where the contaminants are, how they are held up in a given physical and chemical subsurface environment; and knowing the physical, chemical, and microbiological changes that are induced by the various remedial technologies

A microfluidic device for open loop stripping of volatile organic compounds.

Science.gov (United States)

Cvetković, Benjamin Z; Dittrich, Petra S

2013-03-01

The detection of volatile organic compounds is of great importance for assessing the quality of water. In this contribution, we describe a miniaturized stripping device that allows fast online detection of organic solvents in water. The core component is a glass microfluidic chip that facilitates the creation of an annular-flowing stream of water and nitrogen gas. Volatile compounds are transferred efficiently from the water into the gas phase along the microfluidic pathway at room temperature within less than 5 s. Before exiting the microchip, the liquid phase is separated from the enriched gas phase by incorporating side capillaries through which the hydrophilic water phase is withdrawn. The gas phase is conveniently collected at the outlet reservoir by tubing. Finally, a semiconductor gas sensor analyzes the concentration of (volatile) organic compounds in the nitrogen gas. The operation and use of the stripping device is demonstrated for the organic solvents THF, 1-propanol, toluene, ethylbenzene, benzaldehyde, and methanol. The mobile, inexpensive, and continuously operating system with liquid flow rates in the low range of microliters per minute can be connected to other detectors or implemented in chemical production line for process control.

Release of Volatile Compounds from Polymeric Microcapsules Mediated by Photocatalytic Nanoparticles

Directory of Open Access Journals (Sweden)

J. Marques

2013-01-01

Full Text Available In this study we propose a suitable method for the solar-activated controlled release of volatile compounds from polymeric microcapsules bonded with photocatalytic nanoparticles. These reservoirs can find applications, for example, in the controlled release of insecticides, repellents, or fragrances, amongst other substances. The surfaces of the microcapsules have been functionalized with TiO2 nanoparticles. Upon ultraviolet irradiation, redox mechanisms are initiated on the semiconductor surface resulting in the dissociation of the polymer chains of the capsule wall and, finally, volatilization of the encapsulated compounds. The quantification of the output release has been performed by gas chromatography analysis coupled with mass spectroscopy.

Volatile compounds and some physico-chemical properties of pastırma produced with different nitrate levels

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Ahmet Akköse

2017-08-01

Full Text Available Objective The aim of the study was to evaluate the effects of different nitrate levels (150, 300, 450, and 600 ppm KNO3 on the volatile compounds and some other properties of pastırma. Methods Pastırma samples were produced under the controlled condition and analyses of volatile compounds, and thiobarbituric acid reactive substances (TBARS as an indicator of lipid oxidation, non-protein nitrogenous matter content as an indicator of proteolysis, color and residual nitrite were carried out on the final product. The profile of volatile compounds of pastırma samples was analyzed by gas chromatography/mass spectrometry using a solid phase microextraction. Results Nitrate level had a significant effect on pH value (p<0.05 and a very significant effect on TBARS value (p<0.01. No significant differences were determined in terms of aw value, non-protein nitrogenous substance content, color and residual nitrite between pastırma groups produced by using different nitrate levels. Nitrate level had a significant (p<0.05 or a very significant (p<0.01 effect on some volatile compounds. It was determined that the amounts and counts of volatile compounds were lower in the 450 and especially 600 ppm nitrate levels than 150 and 300 ppm nitrate levels (p<0.05. While the use of 600 ppm nitrate did not cause an increase in residual nitrite levels, the use of 150 ppm nitrate did not negatively affect the color of pastırma. However, the levels of volatile compounds decreased with an increasing level of nitrate. Conclusion The use of 600 ppm nitrate is not a risk in terms of residual nitrite in pastırma produced under controlled condition, however, this level is not suitable due to decrease in the amount of volatile compounds.

Influence of the yeast autolysates addition on the volatile compounds of sparkling white wines

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Pérez-Magariño Silvia

2014-01-01

Full Text Available During sparkling wine aging, different compounds such as polysaccharides can be released due to yeast autolysis that can cause important changes in wine composition. Yeast autolysis is a slow natural process that takes long time, and the addition of some products could improve the quality of these wines. The aim of this work was to study the effect of the addition of several commercial yeast autolysates on the volatile composition of white sparkling wines (Godello and Verdejo, and aged on lees for 9 months. The discriminant analyses indicated that the sparkling wines treated with PCP2 showed the highest differences in the volatile composition of both sparkling wines studied, being the ethyl esters, terpenes, decanoic acid and some alcohols, the compounds that were affected in a greater extent. This fact could be due to PCP2 presenting the highest mannoprotein percentage that can interact with volatile compounds, modulating their volatility and perception.

Characterization of selected volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyl compounds at a roadside monitoring station

Science.gov (United States)

Ho, K. F.; Lee, S. C.; Chiu, Gloria M. Y.

Volatile organic compounds (VOCs), PAHs and carbonyl compounds are the major toxic components in Hong Kong. Emissions from motor vehicles have been one of the primary pollution sources in the metropolitan areas throughout Hong Kong for a long time. A 1-yr monitoring program for VOCs, PAHs and carbonyl compounds had been performed at a roadside urban station at Hong Kong Polytechnic University in order to determine the variations and correlations of each selected species (VOCs, PAHs and carbonyl compounds). This study is aimed to analyze toxic volatile organic compounds (benzene, toluene, ethylbenzene and xylene), two carbonyl compounds (formaldehyde, acetaldehyde), and selective polycyclic aromatic hydrocarbons. The monitoring program started from 16 April 1999 to 30 March 2000. Ambient VOC concentrations, many of which originate from the same sources as particulate PAHs and carbonyls compounds, show significant quantities of benzene, toluene and xylenes. Correlations and multivariate analysis of selected gaseous and particulate phase organic pollutants were performed. Source identification by principle component analysis and hierarchical cluster analysis allowed the identification of four sources (factors) for the roadside monitoring station. Factor 1 represents the effect of diesel vehicle exhaust. Factor 2 shows the contribution of aromatic compounds. Factor 3 explains photochemical products—formaldehyde and acetaldehyde. Factor 4 explains the effect of gasoline vehicle exhaust.

PERUBAHAN KOMPOSISI VOLATIL DAGING BUAH MANGGA "KENSINGTON PRIDE" SELAMA PEMASAKAN [Changes in Volatile Compound Composition of Kensington Pride Mango Pulp During Fruit Ripening

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Herianus J.D Lalel

2003-08-01

Full Text Available Volatile compounds of ‘Kesington Pride’ mango produced from the pulp during fruit ripening were studied using headspace solid-phase microextraction (SPME as a sampling method and gas chromatography with a flame ionisation detector (GC-FID and gas chromatography mass spectrophotometry (GC-MS for analysis. Ethylene production and respiration reached a peak on the second and third day of ripening, respectively. Seventy-eight volatile compounds were identified from the pulp of ‘Kesington Pride’ mango; however, only 73 volatile compounds were present in notable amount. The most abundant group of volatile compounds was monoterpenes, accounting for abaout 44% of the total identified compounds, followed by sesquiterpenes (19%, aldehydes (11%,esters (10% aromatics (8%, alcohol (2%, ketones (2%, alkanes (1% and norisoprenoid (1%. -Terpinolene was the major compound during ripening. Except for -pinene, 3,7-dimethl-1,3,7-octatriene, 4-methl-1 (1-methylethylidene-cyclohexene, p-mentha-1,5,8-triene, aloocimene, the concentration of all other monoterpenes increased for the first six or eight days and decreased afterwards. All sesquiteroenes, p-cymene, p-cymen-9-ol,2-ethyl-1,4-dimethl benzene also increased during ripening and peaked on day four, six or eight of ripening. Ketones, aldehydes alkane and cis-3-hexenol, on the other hand, decreased during ripening. Ethanol, esters and norisoprenoid increased quite sharply at the end of ripening period.

Volatile and semivolatile organic compounds in laboratory peat fire emissions

Data.gov (United States)

U.S. Environmental Protection Agency — Supporting information Tables S3 and S4 list emission factors in g/kg of speciated volatile and particulate organic compounds emitted from peat burning. Peat samples...

Inhibition of Enzymatic Browning of Chlorogenic Acid by Sulfur-Containing Compounds

NARCIS (Netherlands)

Kuijpers, T.F.M.; Narvaez Cuenca, C.E.; Vincken, J.P.; Verloop, J.W.; Berkel, van W.J.H.; Gruppen, H.

2012-01-01

The antibrowning activity of sodium hydrogen sulfite (NaHSO3) was compared to that of other sulfur-containing compounds. Inhibition of enzymatic browning was investigated using a model browning system consisting of mushroom tyrosinase and chlorogenic acid (5-CQA). Development of brown color

Associations of Volatile Compounds with Sensory Aroma and Flavor: The Complex Nature of Flavor

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Edgar Chambers IV

2013-04-01

Full Text Available Attempts to relate sensory analysis data to specific chemicals such as volatile compounds have been frequent. Often these associations are difficult to interpret or are weak in nature. Although some difficulties may relate to the methods used, the difficulties also result from the complex nature of flavor. For example, there are multiple volatiles responsible for a flavor sensation, combinations of volatiles yield different flavors than those expected from individual compounds, and the differences in perception of volatiles in different matrices. This review identifies some of the reasons sensory analysis and instrumental measurements result in poor associations and suggests issues that need to be addressed in future research for better understanding of the relationships of flavor/aroma phenomena and chemical composition.

Characterization of Volatile Flavor Compounds in Chinese Rice Wine Fermented from Enzymatic Extruded Rice.

Science.gov (United States)

Xu, Enbo; Long, Jie; Wu, Zhengzong; Li, Hongyan; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan

2015-07-01

Enzymatic extrusion, instead of traditional steam cooking, to treat rice is an efficient and alternative pretreatment for Chinese rice wine fermentation. In order to determine the formation of volatiles in enzymatic extrusion-processed rice wine (EE), and to confirm its characteristic flavor compounds, headspace solid-phase micro-extraction followed by GC-MS was used. A total of 66 volatile compounds were identified in EE. During fermentation, most volatiles generated from enzymatic extruded rice had the similar trends with those from steam-cooked rice, but the differences in the concentration of volatiles indicated a changed balance of flavors release caused by enzymatic extrusion. Besides, the concentrations and sorts of volatiles in EEs fermented from different rice particle sizes, were not dramatically different. By principal component analysis, EE could be distinctly separated from other traditional Chinese rice wines according to its characteristic volatiles, namely, 2-heptanol, 1-octen-3-ol, ethyl 4-hydroxybenzoate, methylpentyl 2-propenoate, γ-hexalactone, and 4-vinylguaiacol. Enzymatic extrusion liquefaction has been a popular thermal treatment for cereals, and gradually being applied in fermentation and liquor-making industry all over the world. The characterization of volatile flavor compounds in Chinese rice wine processed by enzymatic extrusion liquefaction pretreatment, might be made use not only for a better understanding of this new-type rice wine, but for the further utilization of enzymatic extrusion in other wine or alcohol production as well. © 2015 Institute of Food Technologists®

Relationships between volatile compounds and sensory characteristics in virgin olive oil by analytical and chemometric approaches.

Science.gov (United States)

Procida, Giuseppe; Cichelli, Angelo; Lagazio, Corrado; Conte, Lanfranco S

2016-01-15

The volatile fraction of virgin olive oil is characterised by low molecular weight compounds that vaporise at room temperature. In order to obtain an aroma profile similar to natural olfactory perception, the composition of the volatile compounds was determined by applying dynamic headspace gas chromatography, performed at room temperature, with a cryogenic trap directly connected to a gas chromatograph-mass spectrometer system. Samples were also evaluated according to European Union and International Olive Council official methods for sensory evaluation. In this paper, the composition of the volatile fraction of 25 extra virgin olive oils from different regions of Italy was analysed and some preliminary considerations on relationships between chemical composition of volatile fraction and sensory characteristics are reported. Forty-two compounds were identified by means of the particular analytical technique used. All the analysed samples, classified as extra virgin by the panel test, never present peaks whose magnitude is important enough in defected oils. The study was focused on the evaluation of volatile compounds responsible for the positive impact on olive odour properties ('green-fruity' and 'sweet') and olfactory perception. Chemometric evaluation of data, obtained through headspace analysis and the panel test evaluation, showed a correlation between chemical compounds and sensory properties. On the basis of the results, the positive attributes of virgin olive oil are divided into two separated groups: sweet types or green types. Sixteen volatile compounds with known positive impact on odour properties were extracted and identified. In particular, eight compounds seem correlated with sweet properties whereas the green sensation appears to be correlated with eight other different substances. The content of the compounds at six carbon atoms proves to be very important in defining positive attributes of extra virgin olive oils and sensory evaluation. © 2015

Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

Science.gov (United States)

Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

2008-08-15

Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

Sensory irritating potency of some microbial volatile organic compounds (MVOCs) and a mixture of five MVOCs.

Science.gov (United States)

Korpi, A; Kasanen, J P; Alarie, Y; Kosma, V M; Pasanen, A L

1999-01-01

The authors investigated the ability/potencies of 3 microbial volatile organic compounds and a mixture of 5 microbial volatile organic compounds to cause eye and upper respiratory tract irritation (i.e., sensory irritation), with an animal bioassay. The authors estimated potencies by determining the concentration capable of decreasing the respiratory frequency of mice by 50% (i.e., the RD50 value). The RD50 values for 1-octen-3-ol, 3-octanol, and 3-octanone were 182 mg/m3 (35 ppm), 1359 mg/m3 (256 ppm), and 17586 mg/m3 (3360 ppm), respectively. Recommended indoor air levels calculated from the individual RD50 values for 1-octen-3-ol, 3-octanol, and 3-octanone were 100, 1000, and 13000 microg/m3, respectively-values considerably higher than the reported measured indoor air levels for these compounds. The RD50 value for a mixture of 5 microbial volatile organic compounds was also determined and found to be 3.6 times lower than estimated from the fractional concentrations and the respective RD50s of the individual components. The data support the conclusion that a variety of microbial volatile organic compounds may have some synergistic effects for the sensory irritation response, which constrains the interpretation and application of recommended indoor air levels of individual microbial volatile organic compounds. The results also showed that if a particular component of a mixture was much more potent than the other components, it may dominate the sensory irritation effect. With respect to irritation symptoms reported in moldy houses, the results of this study indicate that the contribution of microbial volatile organic compounds to these symptoms seems less than previously supposed.

Application of response surface methodology to optimise supercritical carbon dioxide extraction of volatile compounds from Crocus sativus.

Science.gov (United States)

Shao, Qingsong; Huang, Yuqiu; Zhou, Aicun; Guo, Haipeng; Zhang, Ailian; Wang, Yong

2014-05-01

Crocus sativus has been used as a traditional Chinese medicine for a long time. The volatile compounds of C. sativus appear biologically active and may act as antioxidants as well as anticonvulsants, antidepressants and antitumour agents. In order to obtain the highest possible yield of essential oils from C. sativus, response surface methodology was employed to optimise the conditions of supercritical fluid carbon dioxide extraction of the volatile compounds from C. sativus. Four factorswere investigated: temperature, pressure, extraction time and carbon dioxide flow rate. Furthermore, the chemical compositions of the volatile compounds extracted by supercritical fluid extraction were compared with those obtained by hydro-distillation and Soxhlet extraction. The optimum extraction conditions were found to be: optimised temperature 44.9°C, pressure 34.9 MPa, extraction time 150.2 min and CO₂ flow rate 10.1 L h⁻¹. Under these conditions, the mean extraction yield was 10.94 g kg⁻¹. The volatile compounds extracted by supercritical fluid extraction and Soxhlet extraction contained a large amount of unsaturated fatty acids. Response surface methodology was successfully applied for supercritical fluid CO₂ extraction optimisation of the volatile compounds from C. sativus. The study showed that pressure and CO₂ flow rate had significant effect on volatile compounds yield produced by supercritical fluid extraction. This study is beneficial for the further research operating on a large scale. © 2013 Society of Chemical Industry.

Comparison of methods for determining volatile compounds in cheese, milk, and whey powder

Science.gov (United States)

Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but selecting the proper procedures presents challenges. Heat is applied to drive volatiles from the samp...

Atomic and molecular physics of plasma-based environmental technologies for abatement of volatile organic compounds

International Nuclear Information System (INIS)

Penetrante, B. M.; Hsiao, M. C.; Bardsley, J. N.; Merritt, B. T.; Vogtin, G. E.; Kuthi, A.; Burkhart, C. P.; Bayless, J. R.

1997-01-01

Non-thermal plasma techniques represent a new generation of air emission control technology that potentially could treat large-volume emissions containing dilute concentrations of volatile organic compounds. In order to apply non-thermal plasmas in an industrial scale, it is important to establish the electrical power requirements and byproducts of the process.There is a need for reliable data concerning the primary decomposition mechanisms and subsequent chemical kinetics associated with non- thermal plasma processing of volatile organic compounds. There are many basic atomic and molecular physics issues that are essential in evaluating the economic performance of non-thermal plasma reactors. These studies are important in understanding how the input electrical power is dissipated in the plasma and how efficiently it is converted to the production of the plasma species (radicals, ions or electrons) responsible for the decomposition of the volatile organic compounds. This paper will present results from basic experimental and theoretical studies aimed at identifying the reaction mechanisms responsible for the primary decomposition of various types of volatile organic compounds. (authors)

Development of the colorimetric sensor array for detection of explosives and volatile organic compounds in air

DEFF Research Database (Denmark)

Kostesha, Natalie; Alstrøm, Tommy Sonne; Johnsen, C

2010-01-01

a color difference map which gives a unique fingerprint for each explosive and volatile organic compound. Such sensing technology can be used to screen for relevant explosives in a complex background as well as to distinguish mixtures of volatile organic compounds distributed in gas phase. This sensor......In the framework of the research project 'Xsense' at the Technical University of Denmark (DTU) we are developing a simple colorimetric sensor array which can be useful in detection of explosives like DNT and TNT, and identification of volatile organic compounds in the presence of water vapor in air...

Determination of some volatile compounds in alcoholic beverage by headspace solid-phase microextraction gas chromatography - mass spectrometry

Science.gov (United States)

Schmutzer, G.; Avram, V.; Feher, I.; David, L.; Moldovan, Z.

2012-02-01

The volatile composition of alcoholic beverage was studied by headspace solid-phase microextraction (HSSPME) method and gas chromatography - mass spectrometry (GC-MS). Some volatile compounds, such as alcohols, esters, terpenes and other are mainly responsible for the flavor of fortified wines and their amounts specify the quality of the alcoholic beverages. From this perspective it is interesting to develop a rapid, selective and sensitive analytical method suitable for simultaneous quantification of the main molecules being responsible for the organoleptic characteristic of alcoholic beverages. Vermouth fortified drink was analyzed in order to characterize the volatile profile. Using the HS-SPME/GC-MS a number of twenty-six volatile compounds from a commercial market alcoholic beverage were identified. The most abundant compounds were m-thymol, o-thymol and eugenol, alongside of the ethyl ester compounds.

Volatile compounds in medlar fruit (Mespilus germanica L. at two ripening stages

Directory of Open Access Journals (Sweden)

Veličković Milovan M.

2013-01-01

Full Text Available Medlar is the fruit of Mespilus germanica L. in the family of Rosaceae. The fruit can be eaten only if ‘bletted’ (softened by frost or longer storage. The effect of the maturation stages on the volatile compounds of the medlar fruit was investigated during two different stages. Volatile flavour substances were isolated from the minced pulp of unripe and full ripe medlar fruits by simultaneous steam distillation extraction (SDE with methilen chloride as the extracting solvent. The concentrate was analysed by GC-FID-MS. Hexanoic and hexadecanoic acids were the predominant acids, hexanal and (E-2-hexenal were the predominant aldehydes, (Z-3-hexenol and hexanol were the predominant alcohols, with p-cymene, terpinen-4-ol, and γ-terpiene (the terpenes responsible for the characteristic medlar flavour being also present. The C6 aliphatic compounds, such as hexanal and (E-2-hexenal, were observed as the major volatile constituents in the green stage. In contrast, hexanol and (Z-3-hexenol were the main volatiles in ripe fruits.

Measurement of volatile plant compounds in field ambient air by thermal desorption-gas chromatography-mass spectrometry.

Science.gov (United States)

Cai, Xiao-Ming; Xu, Xiu-Xiu; Bian, Lei; Luo, Zong-Xiu; Chen, Zong-Mao

2015-12-01

Determination of volatile plant compounds in field ambient air is important to understand chemical communication between plants and insects and will aid the development of semiochemicals from plants for pest control. In this study, a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method was developed to measure ultra-trace levels of volatile plant compounds in field ambient air. The desorption parameters of TD, including sorbent tube material, tube desorption temperature, desorption time, and cold trap temperature, were selected and optimized. In GC-MS analysis, the selected ion monitoring mode was used for enhanced sensitivity and selectivity. This method was sufficiently sensitive to detect part-per-trillion levels of volatile plant compounds in field ambient air. Laboratory and field evaluation revealed that the method presented high precision and accuracy. Field studies indicated that the background odor of tea plantations contained some common volatile plant compounds, such as (Z)-3-hexenol, methyl salicylate, and (E)-ocimene, at concentrations ranging from 1 to 3400 ng m(-3). In addition, the background odor in summer was more abundant in quality and quantity than in autumn. Relative to previous methods, the TD-GC-MS method is more sensitive, permitting accurate qualitative and quantitative measurements of volatile plant compounds in field ambient air.

40 CFR 60.542 - Standards for volatile organic compounds.

Science.gov (United States)

2010-07-01

... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542 Standards for volatile organic compounds. (a) On and after the date on which the initial performance test, required by § 60.8, is completed, but no later than...

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part 2, Field tests

Science.gov (United States)

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

The leaf volatile constituents of Isatis tinctoria by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry.

Science.gov (United States)

Condurso, Cettina; Verzera, Antonella; Romeo, Vincenza; Ziino, Marisa; Trozzi, Alessandra; Ragusa, Salvatore

2006-08-01

The leaf volatile constituents of Isatis tinctoria L. (Brassicaceae) have been studied by Solid-Phase Microextraction and Gas chromatography/Mass Spectrometry (SPME/GC-MS). Seventy components were fully characterized by mass spectra, linear retention indices, and injection of standards; the average composition (ppm) as single components and classes of substances is reported. Aliphatic hydrocarbons, acids, alcohols, aldehydes and esters, aromatic aldehydes, esters and ethers, furans, isothiocyanates and thiocyanates, sulfurated compounds, nitriles, terpenes and sesquiterpenes were identified. Leaf volatiles in Isatis tinctoria L. were characterized by a high amount of isothiocyanates which accounted for about 40 % of the total volatile fraction. Isothiocyanates are important and characteristic flavour compounds in Brassica vegetables and the cancer chemo-protective attributes are recently responsible for their growing interest.

Observations of volatile organic compounds over the North Atlantic Ocean: relationships to dominant cyanobacterial populations.

Science.gov (United States)

Swarthout, R.; Rossell, R.; Sive, B. C.; Zhou, Y.; Reddy, C. M.; Valentine, D. L.; Cox, D.

2017-12-01

Marine cyanobacteria are abundant primary producers that can have a major influence on the oceanic biogeochemical cycles. In particular, the prominent cyanobacterial genera Prochlorococcus, Synechococcus, and Trichodesmium can impact the air-sea flux of volatile organic compounds (VOCs) including reactive compounds, such as isoprene, that control the oxidative capacity of the atmosphere and climate-relevant compounds, such as dimethyl sulfide. These groups of cyanobacteria have been estimated to increase in abundance by up to 29% by the end of the century as a result of rising sea surface temperatures and dissolved carbon dioxide concentrations. Given their current and predicted future abundance, understanding the role of different cyanobacterial populations on VOC emissions from the ocean is critical in understanding the future oxidative capacity of the remote atmosphere and climate feedback cycles. During the May 2017 Phosphorus, Hydrocarbons, and Transcriptomics cruise aboard the R/V Neil Armstrong, 160 whole air canister samples were collected along a transect through the North Atlantic from Woods Hole, MA to Bermuda and back with 24-hour stops at nine stations encompassing different nutrient regimes and cyanobacterial populations. At each station, a diurnal time series of samples was collected and higher frequency sampling was conducted during transits of the north wall. Canister samples were analyzed on a five-detector gas chromatography system for over 80 individual VOCs including biogenics, aromatics, chlorinated and brominated compounds, and sulfur containing compounds. Trends in reactive and climate-relevant VOCs will be discussed as a function of the predominant cyanobacterial populations at each sample location. These data provide increased information on the spatial and diurnal variability of trace gases associated with these globally important photosynthetic cyanobacteria.

Analysis of Volatile Compounds from Solanumbetaceum Cav. Fruits from Panama by Head-Space Micro Extraction

Directory of Open Access Journals (Sweden)

Armando A. Durant

2013-01-01

Full Text Available The characterization of the volatile compounds of two varieties of Solanum betaceum Cav. by means of headspace solid-phase microextraction (HS-SPME coupled with gas chromatography-mass spectrometry ( GC-MS i s presented. The HS-SPME method for extraction of the volatiles compounds was optimized by using a 2 3 central composite design. Maximum extraction of volatile compounds was achieved by using a divinylbenzene-carboxen-polydimethylsiloxane (DVB/CAR/PDMS fiber, extraction temperature 76° C, incubation time 44 min, and extraction time of 46 min. The main types of compounds detected in both varieties are terpenoids, followed by aromatics, esters, and aldehydes. Golden-yellow cultivars contained higher levels of esters and terpenes, while the reddish-purple variety contained a significant amount of aromatic compounds. The data structure of the chemical information obtained as well as the relationship between variables was evaluated by means of principal component analysis and cluster analysis.

Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat.

Science.gov (United States)

Domínguez, Rubén; Gómez, María; Fonseca, Sonia; Lorenzo, José M

2014-06-01

The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (Pcooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (Pcooking methods led to increased total volatile compounds (between 366.7 and 633.1AU×10(6)/g dry matter) compared to raw steaks (216.4AU×10(6)/g dry matter). The roasted steaks showed the highest volatile content, indicating that increased cooking temperature increases the formation of volatile compounds. Aldehydes were the most abundant compounds in cooked samples, with amounts of 217.2, 364.5, 283.5 and 409.1AU×10(6)/g dry matter in grilled, microwaved, fried and roasted samples, respectively, whereas esters were the most abundant compounds in raw samples, with mean amounts of 98.8AU×10(6)/g dry matter. Copyright © 2014 Elsevier Ltd. All rights reserved.

Sulfur-Containing Agrochemicals.

Science.gov (United States)

Devendar, Ponnam; Yang, Guang-Fu

2017-10-09

Modern agricultural chemistry has to support farmers by providing innovative agrochemicals. In this context, the introduction of sulfur atoms into an active ingredient is still an important tool in modulating the properties of new crop-protection compounds. More than 30% of today's agrochemicals contain at least one sulfur atom, mainly in fungicides, herbicides and insecticides. A number of recently developed sulfur-containing agrochemical candidates represent a novel class of chemical compounds with new modes of action, so we intend to highlight the emerging interest in commercially active sulfur-containing compounds. This chapter gives a comprehensive overview of selected leading sulfur-containing pesticidal chemical families namely: sulfonylureas, sulfonamides, sulfur-containing heterocyclics, thioureas, sulfides, sulfones, sulfoxides and sulfoximines. Also, the most suitable large-scale synthetic methods of the recently launched or provisionally approved sulfur-containing agrochemicals from respective chemical families have been highlighted.

Selective determination of semi-volatile thiophene compounds in water by molecularly imprinted polymer thin films with direct headspace gas chromatography sulfur chemiluminescence detection.

Science.gov (United States)

Hijazi, Hassan Y; Bottaro, Christina S

2018-02-26

Water-compatible molecularly imprinted polymer (MIP) thin films are coupled with headspace gas chromatography sulfur chemiluminescence detection (HS-GC-SCD) to create a new approach for the determination of trace concentrations of thiophene compounds in water samples. Thiophene compounds are persistent, typically petrogenic, organic pollutants of concern due to their potential for biomagnification and bioaccumulation, mutagenicity, and carcinogenicity in terrestrial and aquatic fauna. Identification and quantitation in water, particularly following oil spills, is a priority. Following adsorption of the thiophenes to the MIPs, the MIP-bound analytes are analyzed directly by HS-GC-SCD, with minimal sample manipulation and virtually no organic solvent. Calibration curves of spiked seawater were linear from 5 μg L -1 to 100 μg L -1 and limits of detection (LOD) were in the range of 0.24-0.82 μg L -1 . Low matrix effects were observed in the analysis of thiophene compounds in seawater making the method suitable for use in fresh and saline waters without modification. Acceptable reproducibility was obtained for analysis of thiophene compounds from spiked seawater samples at RSDs ≤7.0% (n = 3).

Influence of volatile compounds and food preservatives in the ...

African Journals Online (AJOL)

... suppress fumonisisin B1 production to maximum extent. Camphor at a concentration of 15 mg/ml could inhibit fumonisin B1 production among different food preservatives studied. From the above results it is concluded that volatile compounds and food preservatives can be employed in the management of fumonisins (B1) ...

Assessment of the health risks and odor concentration of volatile compounds from a municipal solid waste landfill in China.

Science.gov (United States)

Wu, Chuandong; Liu, Jiemin; Liu, Shihua; Li, Wenhui; Yan, Luchun; Shu, Mushui; Zhao, Peng; Zhou, Peng; Cao, Wenbin

2018-07-01

Municipal solid waste (MSW) landfills are a source of odorous and toxic compounds. In this work, we present an integrated assessment of the odor concentration and human health risks of volatile compounds to evaluate the environmental quality at a MSW landfill. Air samples were collected seasonally from six areas of the landfill with different functions. The total concentrations of the compounds ranged from 204.0 to 7426.7 μg m -3 , and the concentrations in temporarily and permanently capped areas were 50.3 and 83.4% lower than those in the tipping area, respectively. The odor concentration was greatest at the leachate collection tank (1732-6254 ou E m -3 ) and tipping area (1573-4113 ou E m -3 ) and was mainly caused by hydrogen sulfide (57.9 and 49.1%, respectively). Moreover, the odor concentration was positively correlated with the temperature (r = 0.500, p waste areas exceeded acceptable levels. Moreover, the cumulative HI (2.5-5.7) and R (1.0E-04 to 3.4E-04) in the waste areas should receive special attention since they were above acceptable levels during all of the seasons. Aromatic and halogenated compounds dominated the cumulative R, accounting for 79 and 21% of the total, on average, while for the cumulative HI, sulfur compounds contributed the most (67%). Copyright © 2018 Elsevier Ltd. All rights reserved.

Corrosion evaluation of materials in sulfur compound environments

International Nuclear Information System (INIS)

Maoying Teng; Iuanjou Yang

1993-01-01

The para-toluene sulfonic acid (PTSA) serves as a catalyst in producing diethylene glycol dibenzoate (DEGDB) and decomposes with increasing time at elevated temperature. Due to the presence of bisulfite ion, it is important to evaluate the corrosion properties of materials in this metastable environments. A potentiodynamic method was used to screen materials' properties in a PTSA solution. A surface analysis technique was also performed to investigate the oxide films. The critical current density and passive current density were substantially reduced when Fe alloyed with Cr and/or Ni. With the addition of Mo in Fe-Ni-Cr alloys, the critical current density was lowered further to show the beneficial effect of alloyed Mo. A plot of the corrosion rate of materials in DEGDB as a function of Ni/Cr ratio shows the linearity with increasing Ni/Cr ratio, disregard the type of materials. The corrosion rate of pure chromium can be estimated as ∼ 2.0 mpy by extrapolation of the linearity to Ni/Cr = 0. This is also the minimum corrosion rate that even Fe-Ni-Cr alloys were alloyed with Mo. Surface analysis results showed that the dissolution of Fe and/or Ni leads to a higher surface chromium content and results in the formation of chromium oxide on metal surface. This chromium oxide then prevents metal from corrosion. It is concluded that the higher the nickel content the higher the corrosion rate of materials. The composition potential-pH diagrams for Fe-S-H 2 O and Ni-S-H 2 O show that the stability fields of FeS and NiS cover a wide range of pH. The effect of sulfur or sulfide ions in promoting dissolution of Fe and/or Ni are highly possible. The activating influence of sulfur compounds on Ni is stronger than that of Fe, although the highly electronic conductivity of iron sulfides can catalyze the cathodic reaction. Undoubtedly, sulfur compound strongly depassivates high Ni contents materials

Effect of Gamma-Irradiation on the Volatile Flavor Compounds from Dried Ginger (Zingiber officinale Roscoe)

International Nuclear Information System (INIS)

No, K.M.; Seo, H.Y.; Gyawali, Rajendra; Shim, S.L.; Yang, S.H.; Lee, S.J.; Kim, K.S.

2005-01-01

The effect of gamma irradiation on volatile components of Korean dried ginger (Zingiber officinale Roscoe) was studied and compared with non-irradiated sample. Volatile compounds from non- and irradiated samples were extracted using simultaneous distillation-extraction (SDE) apparatus and analyzed by gas chromatography-mass spectrometer (GC/MS). A total of 83 and 71 compounds were identified and quantified from non-and irradiated dried ginger at dose of 10 kGy. Identified components were hydrocarbons, alcohols, aldehydes, esters, ketones and miscellaneous compounds

Nanostructured Polypyrrole-Based Ammonia and Volatile Organic Compound Sensors

Directory of Open Access Journals (Sweden)

Milena Šetka

2017-03-01

Full Text Available The aim of this review is to summarize the recent progress in the fabrication of efficient nanostructured polymer-based sensors with special focus on polypyrrole. The correlation between physico-chemical parameters, mainly morphology of various polypyrrole nanostructures, and their sensitivity towards selected gas and volatile organic compounds (VOC is provided. The different approaches of polypyrrole modification with other functional materials are also discussed. With respect to possible sensors application in medicine, namely in the diagnosis of diseases via the detection of volatile biomarkers from human breath, the sensor interaction with humidity is described as well. The major attention is paid to analytes such as ammonia and various alcohols.

The human volatilome: volatile organic compounds (VOCs) in exhaled breath, skin emanations, urine, feces and saliva.

Science.gov (United States)

Amann, Anton; Costello, Ben de Lacy; Miekisch, Wolfram; Schubert, Jochen; Buszewski, Bogusław; Pleil, Joachim; Ratcliffe, Norman; Risby, Terence

2014-09-01

Breath analysis is a young field of research with its roots in antiquity. Antoine Lavoisier discovered carbon dioxide in exhaled breath during the period 1777-1783, Wilhelm (Vilém) Petters discovered acetone in breath in 1857 and Johannes Müller reported the first quantitative measurements of acetone in 1898. A recent review reported 1765 volatile compounds appearing in exhaled breath, skin emanations, urine, saliva, human breast milk, blood and feces. For a large number of compounds, real-time analysis of exhaled breath or skin emanations has been performed, e.g., during exertion of effort on a stationary bicycle or during sleep. Volatile compounds in exhaled breath, which record historical exposure, are called the 'exposome'. Changes in biogenic volatile organic compound concentrations can be used to mirror metabolic or (patho)physiological processes in the whole body or blood concentrations of drugs (e.g. propofol) in clinical settings-even during artificial ventilation or during surgery. Also compounds released by bacterial strains like Pseudomonas aeruginosa or Streptococcus pneumonia could be very interesting. Methyl methacrylate (CAS 80-62-6), for example, was observed in the headspace of Streptococcus pneumonia in concentrations up to 1420 ppb. Fecal volatiles have been implicated in differentiating certain infectious bowel diseases such as Clostridium difficile, Campylobacter, Salmonella and Cholera. They have also been used to differentiate other non-infectious conditions such as irritable bowel syndrome and inflammatory bowel disease. In addition, alterations in urine volatiles have been used to detect urinary tract infections, bladder, prostate and other cancers. Peroxidation of lipids and other biomolecules by reactive oxygen species produce volatile compounds like ethane and 1-pentane. Noninvasive detection and therapeutic monitoring of oxidative stress would be highly desirable in autoimmunological, neurological, inflammatory diseases and cancer

Prediction of periodontopathic bacteria in dental plaque of periodontal healthy subjects by measurement of volatile sulfur compounds in mouth air.

Science.gov (United States)

Kishi, Mitsuo; Ohara-Nemoto, Yuko; Takahashi, Masahiro; Kishi, Kayo; Kimura, Shigenobu; Aizawa, Fumie; Yonemitsu, Masami

2013-03-01

The aim of this study was to determine whether measurements of volatile sulfur compounds (VSCs) are useful to predict colonization of periodontopathic bacteria. For this purpose, we assessed the relationships among distributions of 4 species of periodontopathic bacteria in tongue coating and dental plaque, oral conditions including VSC concentration in mouth air, and smoking habit of periodontal healthy young subjects. The subjects were 108 young adults (mean age, 23.5±2.56 years) without clinical periodontal pockets. Information regarding smoking habit was obtained by interview. After VSC concentration in mouth, air was measured with a portable sulfide monitor (Halimeter(®)), non-stimulated saliva flow and dental caries status were assessed, and tongue coating and dental plaque samples were collected from the subjects. The tongue coating samples were weighed to determine the amount. The colonization of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Treponema denticola in both tongue coating and plaque samples was investigated using species-specific polymerase chain reaction assays. Significant relationships were observed between the colonization of periodontopathic bacteria in tongue coating and plaque samples, especially that of P. gingivalis. VSC concentration showed the most significant association with colonization of P. gingivalis in both tongue coating and dental plaque. Logistic regression analysis demonstrated that the adjusted partial correlation coefficient [Exp(B)] values for VSC concentration with the colonization of P. gingivalis, P. intermedia, and T. denticola in dental plaque were 135, 35.4 and 10.4, respectively. In addition, smoking habit was also shown to be a significant variable in regression models [Exp(B)=6.19, 8.92 and 2.53, respectively]. Therefore, receiver operating characteristic analysis was performed to predict the colonization of periodontal bacteria in dental plaque in the subjects divided by smoking

Synthesis and biological activity of sulfur compounds showing structural analogy with combretastatin A-4

Energy Technology Data Exchange (ETDEWEB)

Santos, Edson dos A. dos; Prado, Paulo C.; Carvalho, Wanderley R. de; Lima, Ricardo V. de; Beatriz, Adilson; Lima, Denis P. de, E-mail: denis.lima@ufms.br [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Departamento de Quimica; Hamel, Ernest [Screening Technologies Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute at Frederick, National Institutes of Health, Frederick, MD (United States); Dyba, Marzena A. [Basic Science Program , SAIC-Frederick, Inc., Structural Biophysics Laboratory National Cancer Institute, Frederick, MD (United States); Albuquerque, Sergio [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas

2013-09-01

We extended our previous exploration of sulfur bridges as bioisosteric replacements for atoms forming the bridge between the aromatic rings of combretastatin A-4. Employing coupling reactions between 5-iodo-1,2,3-trimethoxybenzene and substituted thiols, followed by oxidation to sulfones with m-CPBA, different locations for attaching the sulfur atom to ring A through the synthesis of nine compounds were examined. Antitubulin activity was performed with electrophoretically homogenous bovine brain tubulin, and activity occurred with the 1,2,3-trimethoxy-4-[(4-methoxyphenyl)thio]benzene (12), while the other compounds were inactive. The compounds were also tested for leishmanicidal activity using promastigote forms of Leishmania braziliensis (MHOM/BR175/M2904),and the greatest activity was observed with 1,2,3-trimethoxy-4-(phenylthio)benzene (10) and 1,2,3-trimethoxy-4-[(4-methoxyphenyl) sulfinyl]benzene (15). (author)

Analysis of Organic Volatile Flavor Compounds in Fermented Stinky Tofu Using SPME with Different Fiber Coatings

Directory of Open Access Journals (Sweden)

Wei Guan

2012-03-01

Full Text Available The organic volatile flavor compounds in fermented stinky tofu (FST were studied using SPME-GC/MS. A total of 39 volatile compounds were identified, including nine esters, seven alcohols, five alkenes, four sulfides, three heterocycles, three carboxylic acids, three ketones, two aldehydes, one phenol, one amine and one ether. These compounds were determined by MS, and conformed by comparison of the retention times of the separated constituents with those of authentic samples and by comparison of retention indexes (RIs of separated constituents with the RIs reported in the literature. The predominant volatile compound in FST was indole, followed by dimethyl trisulfide, phenol, dimethyl disulfide and dimethyl tetrasulfide. In order to find a better extraction time, the extraction times was optimized for each type of SPME fiber; the results show that the best extraction time for Carboxen/PDMS is 60 min, for PDMS/DVB 30 min, for DVB/CAR/PDMS 60 min and for PDMS 75 min. Of the four fibers used in this work, Carboxen/PDMS is found to be the most suitable to extract the organic volatile flavor compounds in fermented stinky tofu.

Lipid oxidation in baked products: impact of formula and process on the generation of volatile compounds.

Science.gov (United States)

Maire, Murielle; Rega, Barbara; Cuvelier, Marie-Elisabeth; Soto, Paola; Giampaoli, Pierre

2013-12-15

This paper investigates the effect of ingredients on the reactions occurring during the making of sponge cake and leading to the generation of volatile compounds related to flavour quality. To obtain systems sensitive to lipid oxidation (LO), a formulation design was applied varying the composition of fatty matter and eggs. Oxidation of polyunsaturated fatty acids (PUFA) and formation of related volatile compounds were followed at the different steps of cake-making. Optimised dynamic Solid Phase Micro Extraction was applied to selectively extract either volatile or semi-volatile compounds directly from the baking vapours. We show for the first time that in the case of alveolar baked products, lipid oxidation occurs very early during the step of dough preparation and to a minor extent during the baking process. The generation of lipid oxidation compounds depends on PUFA content and on the presence of endogenous antioxidants in the raw matter. Egg yolk seemed to play a double role on reactivity: protecting unsaturated lipids from oxidation and being necessary to generate a broad class of compounds of the Maillard reaction during baking and linked to the typical flavour of sponge cake. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of packaging material on enological parameters and volatile compounds of dry white wine.

Science.gov (United States)

Revi, M; Badeka, A; Kontakos, S; Kontominas, M G

2014-01-01

The enological parameters and volatile compounds of white wine packaged in dark coloured glass and two commercial bag-in-box (BIB) pouches (low density polyethylene - LDPE and ethylene vinyl acetate - EVA lined) were determined for a period of 6 months at 20 °C. Parameters monitored included: titratable acidity, volatile acidity, pH, total SO2, free SO2, colour, volatile compounds and sensory attributes. The BIB packaging materials affected the titratable acidity, total and free SO2 and colour of wine. A substantial portion of the wine aroma compounds was adsorbed by the plastic materials or lost to the environment through leakage of the valve fitment. Between the two plastics, the LDPE lined pouch showed a considerably higher aroma sorption as compared to EVA. Wine packaged in glass retained the largest portion of its aroma compounds. Sensory evaluation showed that white wine packaged in both plastics was of acceptable quality for 3 months vs. at least 6 months for that in glass bottles. Copyright © 2013 Elsevier Ltd. All rights reserved.

An investigation on the chemotactic responses of different entomopathogenic nematode strains to mechanically damaged maize root volatile compounds.

Science.gov (United States)

Laznik, Z; Trdan, S

2013-07-01

Entomopathogenic nematodes (EPNs) respond to a variety of stimuli when foraging. In a laboratory investigation, we tested the chemotactic responses of 8 EPN strains (Steinernema and Heterorhabditis) to three mechanically damaged maize root compounds (linalool, α-caryophyllene and β-caryophyllene). We hypothesized that the EPN directional response to the tested volatile compounds would vary among the species and volatile compound and may be related to foraging strategies. The nematodes with an intermediate foraging strategy (Steinernema feltiae) proved to be less active in their movement toward volatile compounds in a comparison with the ambushers (Steinernema carpocapsae) and cruisers (Steinernema kraussei and Heterorhabditis bacteriophora); β-caryophyllene was found to be the most attractive substance in our experiment. The results of our investigation showed that the cruisers were more attracted to β-caryophyllene than the ambushers and intermediates. The foraging strategy did not affect the movement of the IJs toward the other tested volatile compounds or the control. Our results suggest that the response to different volatile cues is more a strain-specific characteristic than a different host-searching strategy. Only S. carpocapsae strain B49 displayed an attraction to linalool, whereas S. kraussei showed a retarded reaction to β-caryophyllene and α-caryophyllene in our experiment. The EPN strains showed only a weak attraction to α-caryophyllene, suggesting that this volatile compound could not have an important role in the orientation of IJs to the damaged roots of maize plants. These results expand our knowledge of volatile compounds as the cues that may be used by EPNs for finding hosts or other aspects of navigation in the soil. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of volatile compounds and food preservatives in the ...

African Journals Online (AJOL)

STORAGESEVER

2009-09-01

Sep 1, 2009 ... On the other hand, vapors of propanol failed to inhibit the growth and fumonisins production. Acetic acid, acetone, butanol and benzene were also not much effec- tive in the control of growth and fumonisins production by. F. moniliforme. The rest of the volatile compounds were mild in their toxicity as they ...

Salt lakes of Western Australia - Natural abiotic formation of volatile organic compounds

Science.gov (United States)

Krause, T.; Studenroth, S.; Mulder, I.; Tubbesing, C.; Kotte, K.; Ofner, J.; Junkermann, W.; Schöler, H. F.

2012-04-01

Western Australia is a semi-/arid region that is heavily influenced by global climate change and agricultural land use. The area is known for its many ephemeral saline and hypersaline lakes with a wide range of hydrogeochemical parameters that have gradually changed over the last fifty years. Historically, the region was covered by eucalyptus trees and shrubs, but was cleared mainly within 10 years after WWII to make room for wheat and live stock. After the clearance of the deep rooted native plants the groundwater started to rise, bringing increased amounts of dissolved salts and minerals to the surface and discharging them into streams and lakes. Thus most of Western Australia is influenced by secondary salinisation (soil salting) [1]. Another problem is that the discharged minerals affect the pH of ground and surface water, which ranges from acidic to slightly basic. During the 2011 campaign surface water was measured with a pH between 2.5 and 7.1. Another phenomenon in Western Australia is the decrease of rainfall over the last decades assumed to be linked to the secondary salinisation. The rising saline and mineral rich groundwater increases the biotical and abiotical activity of the salt lakes. Halogenated and non-halogenated volatile organic compounds emitted from those lakes undergo fast oxidation and chemical reactions to form small particles modifying cloud microphysics and thus suppressing rain events [2]. Our objective is to gain a better understanding of this extreme environment with its hypersaline acidic lakes with regard to the potential abiotic formation of volatile organic compounds and its impact on the local climate. In spring 2011 fifty-three sediment samples from ten salt lakes in the Lake King region where taken, freeze-dried and ground. In order to simulate the abiotic formation of volatile organic compounds the soil samples were resuspended with water in gas-tight headspace vials. The headspace was measured using a purge and trap GC

Chemical Composition of the Volatile Components of Tropaeolum majus L. (Garden Nasturtium from North Western Algeria

Directory of Open Access Journals (Sweden)

B. BENYELLES

2015-11-01

Full Text Available Essential oil from Tropaeolum majus L. aerial parts, a plant native to North Western Algeria, was obtained by hydrodistillation. The oil volatile components were identified by a combination of gas chromatography/flame ionization detection (GC/FID, GC-mass spectrometry (GC-MS techniques, and NMR spectroscopy. Nine components representing 92.0 % of the essential oil total (GC/FID chromatogram were identified. The most abundant compounds were benzyl isothiocyanate (82.5 %, benzene acetonitrile (3.9 % and 2-phenylethyl isovalerate (2.9 %. Higher content in nitrogen- and sulfur-containing compounds accounting to 86.4 % of the volatile fraction composition of T. majus were quantified.

Volatile organic compounds in the unsaturated zone from radioactive wastes

Science.gov (United States)

Baker, Ronald J.; Andraski, Brian J.; Stonestrom, David A.; Luo, Wentai

2012-01-01

Volatile organic compounds (VOCs) are often comingled with low-level radioactive wastes (LLRW), but little is known about subsurface VOC emanations from LLRW landfills. The current study systematically quantified VOCs associated with LLRW over an 11-yr period at the USGS Amargosa Desert Research Site (ADRS) in southwestern Nevada. Unsaturated-zone gas samples of VOCs were collected by adsorption on resin cartridges and analyzed by thermal desorption and GC/MS. Sixty of 87 VOC method analytes were detected in the 110-m-thick unsaturated zone surrounding a LLRW disposal facility. Chlorofluorocarbons (CFCs) were detected in 100% of samples collected. Chlorofluorocarbons are powerful greenhouse gases, deplete stratospheric ozone, and are likely released from LLRW facilities worldwide. Soil-gas samples collected from a depth of 24 m and a horizontal distance 100 m south of the nearest waste-disposal trench contained >60,000 ppbv total VOCs, including >37,000 ppbv CFCs. Extensive sampling in the shallow unsaturated zone (0–2 m deep) identified areas where total VOC concentrations exceeded 5000 ppbv at the 1.5-m depth. Volatile organic compound concentrations exceeded background levels up to 300 m from the facility. Maximum vertical diffusive fluxes of total VOCs were estimated to be 1 g m-2 yr-1. Volatile organic compound distributions were similar but not identical to those previously determined for tritium and elemental mercury. To our knowledge, this study is the first to characterize the unsaturated zone distribution of VOCs emanating from a LLRW landfill. Our results may help explain anomalous transport of radionuclides at the ADRS and elsewhere.

Biogenic volatile organic compounds from the urban forest of the Metropolitan Region, Chile

International Nuclear Information System (INIS)

Préndez, Margarita; Carvajal, Virginia; Corada, Karina; Morales, Johanna; Alarcón, Francis; Peralta, Hugo

2013-01-01

Tropospheric ozone is a secondary pollutant whose primary sources are volatile organic compounds and nitrogen oxides. The national standard is exceeded on a third of summer days in some areas of the Chilean Metropolitan Region (MR). This study reports normalized springtime experimental emissions factors (EF) for biogenic volatile organic compounds from tree species corresponding to approximately 31% of urban trees in the MR. A Photochemical Ozone Creation Index (POCI) was calculated using Photochemical Ozone Creation Potential of quantified terpenes. Ten species, natives and exotics, were analysed using static enclosure technique. Terpene quantification was performed using GC-FID, thermal desorption, cryogenic concentration and automatic injection. Observed EF and POCI values for terpenes from exotic species were 78 times greater than native values; within the same family, exotic EF and POCI values were 28 and 26 times greater than natives. These results support reforestation with native species for improved urban pollution management. -- First experimental determination of the emission factors of biogenic volatile organic compounds in the urban forest of the Metropolitan Region, Chile

Volatile compound diversity and conserved alarm behaviour in Triatoma dimidiata.

Science.gov (United States)

May-Concha, Irving; Rojas, Julio C; Cruz-López, Leopoldo; Ibarra-Cerdeña, Carlos N; Ramsey, Janine M

2015-02-06

Triatoma dimidiata (Latreille) is a key vector complex of Trypanosoma cruzi, etiologic agent of Chagas disease, as it spans North, Central, and South America. Although morphological and genetic studies clearly indicate existence of at least five clades within the species, there has been no robust or systematic revision, or appropriate nomenclature change for species within the complex. Three of the clades (haplogroups) are distributed in Mexico, and recent evidence attests to dispersal of clades across previously "presumed" monotypic geographic regions. Evidence of niche conservatism among sister species of this complex suggests that geographic dispersal is possible for non-sympatric populations, although no information is available on the behavioural aspects of potential interclade interactions, for instance whether differentiation of chemical signaling or response to these signals could impede communication among the haplogroups. Volatiles emitted by disturbed bugs, Brindley's (BGs), and metasternal (MGs) glands were identified using solid-phase micro-extraction (SPME) and gas chromatography coupled mass spectrometry (GC-MS). Volatile compounds emitted by BGs and MGs, and those secreted by disturbed nymphs and adults, of the three Mexican T. dimidiata haplogroups were tested for avoidance behaviour by conspecific nymphs and adults using an olfactometer. Triatoma dimidiata haplogroups all have three age-related alarm responses: absence of response by early stage nymphs, stage-specific response by 4-5th stage nymphs, and a shared 4-5th nymph and adult response to adult compounds. Disturbed bugs released 15 to 24 compounds depending on the haplogroup, among which were three pyrazines, the first report of these organoleptics in Triatominae. Isobutyric acid from BGs was the most abundant molecule in the response in all haplogroups, in addition to 15 (h1) to 21 (h2 and h3) MG compounds. Avoidance behaviour of disturbed bugs and volatiles emitted by BGs were haplogroup

New method for reduction of burning sulfur of coal

International Nuclear Information System (INIS)

Lyutskanov, L.; Dushanov, D.

1998-01-01

The coal pyrolysis is key phase in the the pyrolysis-combustion cycle as it provides char for combustor. The behaviour of sulfur compounds during coal pyrolysis depends on factors as rank of coal, quantity of sulfur and sulfur forms distribution in the coal, quantity and kind of mineral matter and the process conditions. The mineral content of coal may inhibit or catalyze the formation of volatile sulfur compounds. The pyrolysis itself is a mean of removing inorganic and organic sulfur but anyway a portion of it remains in the char while the other moves into the tar and gas. The aim of this study was to determine an optimal reduction of burning sulfur at the coal pyrolysis by varying parametric conditions. The pyrolysis of different kinds of coal has been studied. The samples with size particles o C at atmospheric pressure and with a heating rate of 6-50 o C min -1 . They were treated with exhaust gas and nitrogen at an addition of steam and air. The char obtained remains up to 10 min at the final temperature. The char samples cool without a contact with air. Two methods of desulfurization-pyrolysis were studied - using 9-vertical tubular reactor and 9-horizontal turning reactor. The results obtained show that at all samples there is a decrease of burning sulfur with maximal removal efficiency 83%. For example at a pyrolysis of Maritsa Iztok lignite coal the burning sulfur is only 16% in comparison with the control sample. The remained is 90% sulfate, 10% organic and pyrite traces when a mixture 'exhaust gas-water stream-air' was used. The method of desulfurization by pyrolysis could be applied at different kinds of coal and different conditions. Char obtained as a clean product can be used for generating electric power. This innovation is in a stage of patenting

Volatile earliest Triassic sulfur cycle

DEFF Research Database (Denmark)

Schobben, Martin; Stebbins, Alan; Algeo, Thomas J.

2017-01-01

model experiment. Exposure of evaporite deposits having a high δ 34S may account for the source change, with a possible role for the Siberian Traps volcanism by magmatic remobilization of Cambrian rock salt. A high sulfur cycle turnover rate would have left the ocean system vulnerable to development......Marine biodiversity decreases and ecosystem destruction during the end-Permian mass extinction (EPME) have been linked to widespread marine euxinic conditions. Changes in the biogeochemical sulfur cycle, microbial sulfate reduction (MSR), and marine dissolved sulfate concentrations during...... fractionation and point to a more universal control, i.e., contemporaneous seawater sulfate concentration.The MSR-trend transfer function yielded estimates of seawater sulfate of 0.6-2.8mM for the latest Permian to earliest Triassic, suggesting a balanced oceanic S-cycle with equal S inputs and outputs...

Identification of the predominant volatile compounds produced by Aspergillus flavus.

Science.gov (United States)

Kamiński, E; Libbey, L M; Stawicki, S; Wasowicz, E

1972-11-01

A culture of Aspergillus flavus grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH(2)Cl(2), and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and cis-2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the cis designation to 2-octen-1-ol. Both oct-1-en-3-ol and cis-2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.

A dynamic two-dimensional system for measuring volatile organic compound volatilization and movement in soils.

Science.gov (United States)

Allaire, S E; Yates, S R; Ernst, F F; Gan, J

2002-01-01

There is an important need to develop instrumentation that allows better understanding of atmospheric emission of toxic volatile compounds associated with soil management. For this purpose, chemical movement and distribution in the soil profile should be simultaneously monitored with its volatilization. A two-dimensional rectangular soil column was constructed and a dynamic sequential volatilization flux chamber was attached to the top of the column. The flux chamber was connected through a manifold valve to a gas chromatograph (GC) for real-time concentration measurement. Gas distribution in the soil profile was sampled with gas-tight syringes at selected times and analyzed with a GC. A pressure transducer was connected to a scanivalve to automatically measure the pressure distribution in the gas phase of the soil profile. The system application was demonstrated by packing the column with a sandy loam in a symmetrical bed-furrow system. A 5-h furrow irrigation was started 24 h after the injection of a soil fumigant, propargyl bromide (3-bromo-1-propyne; 3BP). The experience showed the importance of measuring lateral volatilization variability, pressure distribution in the gas phase, chemical distribution between the different phases (liquid, gas, and sorbed), and the effect of irrigation on the volatilization. Gas movement, volatilization, water infiltration, and distribution of degradation product (Br-) were symmetric around the bed within 10%. The system saves labor cost and time. This versatile system can be modified and used to compare management practices, estimate concentration-time indexes for pest control, study chemical movement, degradation, and emissions, and test mathematical models.

Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

DEFF Research Database (Denmark)

FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

1992-01-01

Isotope exchange reactions between S-35-labeled sulfur compounds were studied in anoxic estuarine sediment slurries at 21-degrees-C and pH 7.4-7.7. Two experiments labeled with radioactive elemental sulfur (S-35-degrees) and one labeled with radioactive sulfate ((SO42-)-S-35) were performed as time......% of the total S-35 was recovered in the SIGMA-HS- pool in less than 1.5 h. With no detectable SIGMA-HS- (less than 1-mu-M) in the slurry, 58% of the total S-35 was observed in the pyrite pool within 1.5 h. The FeS pool received up to 31% of all S-35 added. The rapid S-35 incorporation from S-35-degrees...... into SIGMA-HS- and FeS pools was explained by isotope exchange reactions. In contrast, there was evidence that the radioactivity observed in the 'pyrite pool' was caused by adhesion of the added S-35-degrees to the FeS2 grains. In all S-35-degrees-labeled experiments we also observed oxidation...

[Study on two preparation methods for beta-CD inclusion compound of four traditional Chinese medicine volatile oils].

Science.gov (United States)

Li, Hailiang; Cui, Xiaoli; Tong, Yan; Gong, Muxin

2012-04-01

To compare inclusion effects and process conditions of two preparation methods-colloid mill and saturated solution-for beta-CD inclusion compound of four traditional Chinese medicine volatile oils and study the relationship between each process condition and volatile oil physical properties and the regularity of selective inclusion of volatile oil components. Volatile oils from Nardostachyos Radix et Rhizoma, Amomi Fructus, Zingiberis Rhizoma and Angelicaesinensis Radix were prepared using two methods in the orthogonal test. These inclusion compounds by optimized processes were assessed and compared by such methods as TLC, IR and scanning electron microscope. Inclusion oils were extracted by steam distillation, and the components found before and after inclusion were analyzed by GC-MS. Analysis showed that new inclusion compounds, but inclusion compounds prepared by the two processes had differences to some extent. The colloid mill method showed a better inclusion effect than the saturated solution method, indicating that their process conditions had relations with volatile oil physical properties. There were differences in the inclusion selectivity of components between each other. The colloid mill method for inclusion preparation is more suitable for industrial requirements. To prepare volatile oil inclusion compounds with heavy gravity and high refractive index, the colloid mill method needs longer time and more water, while the saturated solution method requires higher temperature and more beta-cyclodextrin. The inclusion complex prepared with the colloid mill method contains extended molecular weight chemical composition, but the kinds of components are reduced.

Volatile Compounds of the Leaves and Flowers of Lavandula dhofarensis A.G. Miller

Directory of Open Access Journals (Sweden)

John R. Williams

2013-12-01

Full Text Available The leaves and flowers of Lavandula dhofarensis were collected from the Dhofar region of Oman and hydro-distilled to give low boiling volatiles, which did not condense at 10 oC.  The dichloromethane extract of the hydrosol was analyzed by GC/FID and GC/MS. Sixty four compounds were identified in the volatiles of the leaves, accounting for 78.7% of the total.  The major components were caryophyllene oxide (8.0%, germacrene (7.9%, spathulenol (7.8%, and b-caryophyllene (6.6%. Eighty six compounds were also identified in the volatiles of the leaves plus flowers, comprising 94.5% of the total. The major compounds were camphor (12.9%, viridiflorol (10.5%, a-terpinyl acetate (7.5%, valerenal (7.2%, a-gurjunene (5.6%, and spathulenol (5.5%. Compounds such as linalool, linalyl acetate, 1,8-cineole, and b-ocimene, which are usually found as the major components of lavender oils, were either absent or detected at low levels  (<0.1% in the hydrosol of L. dhofarensis. This investigation showed that the fragrance essence of L. dhofarensis is different from the other Lavandula species. L. dhofarensisis is regionally endemic to wetter areas of Oman.

Modeling long-term uptake and re-volatilization of semi-volatile organic compounds (SVOCs) across the soil-atmosphere interface.

Science.gov (United States)

Bao, Zhongwen; Haberer, Christina; Maier, Uli; Beckingham, Barbara; Amos, Richard T; Grathwohl, Peter

2015-12-15

Soil-atmosphere exchange is important for the environmental fate and atmospheric transport of many semi-volatile organic compounds (SVOCs). This study focuses on modeling the vapor phase exchange of semi-volatile hydrophobic organic pollutants between soil and the atmosphere using the multicomponent reactive transport code MIN3P. MIN3P is typically applied to simulate aqueous and vapor phase transport and reaction processes in the subsurface. We extended the code to also include an atmospheric boundary layer where eddy diffusion takes place. The relevant processes and parameters affecting soil-atmosphere exchange were investigated in several 1-D model scenarios and at various time scales (from years to centuries). Phenanthrene was chosen as a model compound, but results apply for other hydrophobic organic compounds as well. Gaseous phenanthrene was assumed to be constantly supplied to the system during a pollution period and a subsequent regulation period (with a 50% decline in the emission rate). Our results indicate that long-term soil-atmosphere exchange of phenanthrene is controlled by the soil compartment - re-volatilization thus depends on soil properties. A sensitivity analysis showed that accumulation and transport in soils in the short term is dominated by diffusion, whereas in the long term groundwater recharge and biodegradation become relevant. As expected, sorption causes retardation and slows down transport and biodegradation. If atmospheric concentration is reduced (e.g. after environmental regulations), re-volatilization from soil to the atmosphere occurs only for a relatively short time period. Therefore, the model results demonstrate that soils generally are sinks for atmospheric pollutants. The atmospheric boundary layer is only relevant for time scales of less than one month. The extended MIN3P code can also be applied to simulate fluctuating concentrations in the atmosphere, for instance due to temperature changes in the topsoil. Copyright �

The role of the canonical biplot method in the study of volatile compounds in cheeses of variable composition

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Martin, M.I.; Vicente Tavera, S.; Revilla Martin, I.; Vivar Quintana, A.M.; Gonzalez Perez, C.; Hernandez Hierro, J.M.; Lobos Ortega, I.A.

2016-07-01

The canonical biplot method (CB) is used to determine the discriminatory power of volatile chemical compounds in cheese. These volatile compounds were used as variables in order to differentiate among 6 groups or populations of cheeses (combinations of two seasons (winter and summer) with 3 types of cheese (cow, sheep and goat’s milk). We analyzed a total of 17 volatile compounds by means of gas chromatography coupled with mass detection. The compounds included aldehydes and methyl-aldehydes, alcohols (primary, secondary and branched chain), ketones, methyl-ketones and esters in winter (WC) and summer (SC) cow’s cheeses, winter (WSh) and summer (SSh) sheep’s cheeses and in winter (WG) and summer (SG) goat’s cheeses. The CB method allows differences to be found as a function of the elaboration of the cheeses, the seasonality of the milk, and the separation of the six groups of cheeses, characterizing the specific volatile chemical compounds responsible for such differences. (Author)

The fight against Volatile Organic Compounds (VOC)

International Nuclear Information System (INIS)

Anon.

1993-01-01

This paper strikes the balance of the fight against organic volatile compounds emissions in France and in Europe. The first part describes the influence of VOC on production of Ozone in troposphere and gives numerical data on permissive emission values in atmosphere. The second part describes french and european policy and regulations. The third part gives the principle methods and devices for COV measurement in the atmosphere. In the last part, effluents treatment is given: thermal incineration, catalytic incineration, adsorption on active carbon, biologic purification, condensation and separative processes on membrane

Beyond the network of plants volatile organic compounds

OpenAIRE

Vivaldo, Gianna; Masi, Elisa; Taiti, Cosimo; Caldarelli, Guido; Mancuso, Stefano

2017-01-01

Plants emission of volatile organic compounds (VOCs) is involved in a wide class of ecological functions, as VOCs play a crucial role in plants interactions with biotic and abiotic factors. Accordingly, they vary widely across species and underpin differences in ecological strategy. In this paper, VOCs spontaneously emitted by 109 plant species (belonging to 56 different families) have been qualitatively and quantitatively analysed in order to classify plants species. By using bipartite netwo...

Biologically produced sulfur

NARCIS (Netherlands)

Kleinjan, W.E.; Keizer, de A.; Janssen, A.J.H.

2003-01-01

Sulfur compound oxidizing bacteria produce sulfur as an intermediate in the oxidation of hydrogen sulfide to sulfate. Sulfur produced by these microorganisms can be stored in sulfur globules, located either inside or outside the cell. Excreted sulfur globules are colloidal particles which are

Factors Effecting the Total Volatile Organic Compound (TVOC Concentrations in Slovak Households

Directory of Open Access Journals (Sweden)

Ľudmila Mečiarová

2017-11-01

Full Text Available Thirty five Slovak households were selected for an investigation of indoor environmental quality. Measuring of indoor air physical and chemical factors and a questionnaire survey was performed during May 2017. The range of permissible operative temperature was not met in 11% of objects. Relative humidity met the legislative requirements in all monitored homes. Concentrations of total volatile organic compounds (TVOCs were significantly higher in the apartments than in the family houses. The average TVOC levels in the apartments and family houses were 519.7 µg/m3 and 330.2 µg/m3, respectively. Statistical analysis confirmed the effect of indoor air temperature, relative humidity and particulate matter (PM0.5 and PM1 on the levels of TVOCs. Higher TVOC levels were observed also in homes where it is not a common practice to open windows during cleaning activities. Other factors that had a statistically significant effect on concentrations of volatile organic compounds were heating type, attached garage, location of the apartment within residential building (the floor, as well as number of occupants. Higher TVOC concentrations were observed in indoor than outdoor environment, while further analysis showed the significant impact of indoor emission sources on the level of these compounds in buildings. The questionnaire study showed a discrepancy between objective measurement and subjective assessment in the household environment, and pointed to insufficient public awareness about volatile organic compounds (VOCs.

Radiation induced sulfur dioxide removal

International Nuclear Information System (INIS)

Chmielewski, A.G.

2000-01-01

The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

Changes in SPME-extracted volatile compounds from Iberian ham during ripening

Directory of Open Access Journals (Sweden)

García, Carmen

2009-07-01

Full Text Available A headspace SPME procedure was tested to study the evolution of volatile compounds during the ripening of Iberian hams from pigs reared in a Montanera system (outdoorbased, with acorn and pasture available and a HO-Pienso system (indoor-based, with a high oleic acid concentrate. The effect of the ripening time on volatile compounds was more marked than the effect of feeding system. Most volatile compounds affected by the ripening time were compounds that come from Strecker and Maillard reactions, which increased significantly ( p Un procedimiento de microextración en fase sólida (SPME en espacio de cabeza fue ensayado para estudiar la evolución de los compuestos volátiles durante la curación de Jamones Ibéricos de cerdos criados en régimen de montanera (en libertad, con bellotas y pasto disponible y un sistema OH-Pienso (estabulados, con un pienso alto en ácido oléico. El efecto del tiempo de curación en los compuestos volátiles fue más marcado que el efecto de la alimentación. La mayoría de los compuestos volátiles afectados por el tiempo de curación fueron compuestos que proceden de la reacción de Strecker y Maillard, que se incrementaron significativamente (p p < 0.05. Algunos de ellos (ácido butanoico, 2,6- dimetilpiracina y 1-octen-3-ol fueron más abundantes en jamones de Montanera que en jamones de Pienso. Estas pequeñas diferencias podrían ser importantes porque los compuestos involucrados han sido identificados como aromas del jamón Ibérico.

Potential for ion-induced nucleation of volatile organic compounds by radon decay in indoor environments

International Nuclear Information System (INIS)

Daisey, J.M.

1991-11-01

There is considerable interest in the ''unattached'' fraction of radon progeny in indoor air because of its significance to the estimation of the risks of radon exposure. Because of its high mobility in air, the unattached fraction is more efficiently deposited in the respiratory tract. Variation in the diameter of the ''unattached'' fraction and in its diffusion coefficient can be due to clustering of other atmospheric species around the 218 PoO 2 + ion. The purpose of this study was to investigate the potential for the formation of clusters of vapor phase organic compounds, found in indoor air, around the 218 PoO 2 + ion and to determine which were most likely to form clusters. A secondary purpose was to provide a compilation of measurements of indoor organic compounds for future experiments and theoretical calculations by the radon research community. The classical charged liquid droplet theory (Thomson equation) was used to estimate the Gibbs free energy of ion-induced nucleation and to provide an indication of the indoor organic compounds most likely to undergo ion-induced nucleation. Forty-four volatile and semi-volatile organic compounds out of the more than 300 which have been reported in indoor air were investigated. Water vapor was included for comparison. The results indicate that there is a potential for the formation of clusters of organic compounds around the 218 PoO 2 + ion. The compounds with the greatest potential for cluster formation are the volatile oxidized hydrocarbons (e.g., n-butanol, phenol, hexanal, nonanal, benzaldehyde, the ketones and the acetates) and the semi-volatile organic compounds (pentachlorophenol, nicotine, chlordane, chlorpyrifos)

Removal of sulfur compounds from diesel using ArF laser and oxygen.

Science.gov (United States)

Gondal, M A; Siddiqui, M N; Al-Hooshani, K

2013-01-01

A laser-based technique for deep desulfurization of diesel and other hydrocarbon fuels by removal of dimethyldibenzothiophene (DMDBT), a persistent sulfur contaminant in fuel oils has been developed. We report a selective laser excitation of DMDBT in diesel and model compounds such as n-hexane in a reaction chamber under oxygen environment where oxidative reactions can take place. ArF laser emitting at 193 nm was employed for excitation of oxygen and DMDBT, while for process optimization, the laser energy was varied from 50 to 200 mJ/cm(2). The laser-irradiated DMDBT solution under continuous oxygen flow was analyzed by UV absorption spectrometer to determine the photochemical oxidative degradation of DMDBT. In just 5 min of laser irradiation time, almost 95% DMDBT was depleted in a diesel containing 200 ppm of DMDBT. This article provides a new method for the removal of sulfur compounds from diesel by laser based photochemical process.

Volatile compounds emitted by diverse phytopathogenic microorganisms promote plant growth and flowering through cytokinin action

Czech Academy of Sciences Publication Activity Database

Sanchez-Lopez, A.; Baslam, M.; De Diego, N.; Jose Munoz, F.; Bahaji, A.; Almagro, G.; Ricarte-Bermejo, A.; Garcia-Gomez, P.; Li, J.; Humplík, J.F.; Novák, Ondřej; Spíchal, L.; Doležal, Karel; Baroja-Fernandez, E.; Pozueta-Romero, J.

2016-01-01

Roč. 39, č. 12 (2016), s. 2592-2608 ISSN 0140-7791 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : exceptionally high-levels * tandem mass-spectrometry * arabidopsis-thaliana * nitric-oxide * bacterial volatiles * floral transition * anthocyanin biosynthesis * transgenic arabidopsis * liquid-chromatography * organic-compounds * cytokinin * flowering * growth promotion * microbial volatile compounds * photoregulation * photosynthesis * plant-microbe interaction * starch Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 6.173, year: 2016

Volatile organic compounds released by blowfly larvae and pupae: new perspectives in forensic entomology.

Science.gov (United States)

Frederickx, C; Dekeirsschieter, J; Brostaux, Y; Wathelet, J-P; Verheggen, F J; Haubruge, E

2012-06-10

To evaluate postmortem intervals (PMIs), one should take into account the determined age of necrophagous flies present on the cadaver. However, PMI determination needs further improvement, and rapid and accurate approaches have therefore to be developed. While previous studies have focussed on insect cuticular hydrocarbons, here we explore the volatile profile released by larvae and pupae of Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). We monitored changes in volatile compounds daily, by headspace solid-phase microextraction, followed by gas chromatography-mass spectrometry. Branched and unbranched hydrocarbons, alcohols, esters and acids were identified, and the volatile profile was shown to vary, in both composition and quantity, with the age of the larva/pupa under investigation. We concluded, based on the analysis of the released volatile organic compounds, that it is possible to increase the accuracy of the estimated PMI, through improved estimation of the age of blowflies present on the cadaver. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

75 FR 57390 - Approval and Promulgation of Implementation Plans; Alabama: Volatile Organic Compounds

Science.gov (United States)

2010-09-21

... Environmental Management (ADEM) on March 3, 2010. The revision modifies the definition of ``volatile organic... the VOC definition on the basis that these compounds make a negligible contribution to tropospheric..., 2009, which excludes these compounds from the regulatory VOC definition. This action is being taken...

Comparison of methods for determining volatile compounds in milk, cheese, and whey powder

Science.gov (United States)

Solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted for optimal SPME release while not generating new compounds that are abs...

Distribution of Total Volatile Organic Compounds at taxi drivers in Tehran

Directory of Open Access Journals (Sweden)

Seyyed Mohammad Javad Golhosseini

2015-06-01

Full Text Available Air pollution is currently the most serious environmental health threat worldwide. Volatile Organic Compounds (VOC are considered as the main effective factors in causing air pollution. Vehicles are among the major sources which emit these compounds, so it seems that automobiles’ microenvironment is one of the places where people are exposed to high concentration of VOC. Evaluating the exposure amount of Total Volatile Organic Compounds (TVOC can indeed be used as an indicator to estimate the amount of exposure to every individual VOC. This study was conducted on the concentration of TVOC inside Tehran taxies for a period of one year. For this purpose, a real time instrument equipped with photo-ionization detector (PID was used. Consequently, the highest and the lowest measured TVOC in taxies equaled 3.33 ppm and 0.72 ppm, respectively. In addition, the arithmetic mean of TVOC concentration was 1.77±0.53 ppm inside the examined taxies. In this study, the parameters like measurement time, climate and vehicle conditions were found to have significant effect on the amount of exposure to TVOC.

Novel collection method for volatile organic compounds (VOCs) from dogs

Science.gov (United States)

Host derived chemical cues are an important aspect of arthropod attraction to potential hosts. Host cues that act over longer distances include CO2, heat, and water vapor, while cues such as volatile organic compounds (VOCs) act over closer distances. Domestic dogs are important hosts for disease cy...

Distribution of volatile organic compounds over a semiconductor Industrial Park in Taiwan.

Science.gov (United States)

Chiu, Kong-Hwa; Wu, Ben-Zen; Chang, Chih-Chung; Sree, Usha; Lo, Jiunn-Guang

2005-02-15

This study examined volatile organic compounds (VOC) concentration in ambient air collected during the years 2000--2003 at several different locations of Hsinchu Science-based Industrial Park (HSIP) in Taiwan. A canister automated GC-MS system analyzed the volatile organics in ambient air grasp samples according to T0-15 method. Oxygenated volatiles were the most abundant VOC detected in HSIP followed by aromatics that are commonly used as solvents in the semiconductor industries. The major components measured in the ambient air are 2-propanol (29-135 ppbv), acetone (12-164 ppbv), benzene (0.7-1.7 ppbv), and toluene (13-20 ppbv). At some of the sampling locations, odorous compounds such as carbon disulfide and dimethyl sulfide levels exceed threshold values. The estimated toluene/benzene ratio is very high at most of the sites. However, the total amount of VOC is reduced over the years from 2000 to 2003 due to strict implementation on use and discharge of solvents in industries. There exists no definite seasonal pattern for sporadic occurrence of high levels of some of the volatile organics. Stagnant weather conditions with low wind speeds aid accumulation of toxic species at ground level. The results entail that hi-tech semiconductor industries are still a potential source for harmful organic substances to surrounding microenvironment.

Volatile compounds in whole meal bread crust: The effects of yeast level and fermentation temperature.

Science.gov (United States)

Nor Qhairul Izzreen, M N; Hansen, Se S; Petersen, Mikael A

2016-11-01

The influence of fermentation temperatures (8°C, 16°C, and 32°C) and yeast levels (2%, 4%, and 6% of the flour) on the formation of volatile compounds in the crust of whole meal wheat bread was investigated. The fermentation times were regulated to optimum bread height for each treatment. The volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In all crust samples 28 volatile compounds out of 58 compounds were identified and the other 30 compounds were tentatively identified. Higher fermentation temperatures promoted the formation of Maillard reaction products 3-methyl-1-butanol, pyrazine, 2-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-vinylpyrazine, 3-hydroxy-2-butanone, 3-(methylsulfanyl)-propanal, and 5-methyl-2-furancarboxaldehyde whereas at lower temperature (8°C) the formation of 2- and 3-methylbutanal was favored. Higher levels of yeast promoted the formation of 3-methyl-1-butanol, 2-methyl-1-propanol and 3-(methylsulfanyl)-propanal, whereas hexanal was promoted in the crust fermented with lower yeast level. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adsorption of sulfur compound utilizing rice husk ash modified with niobium

International Nuclear Information System (INIS)

Cavalcanti, Rodrigo M.; Pessoa Júnior, Wanison A.G.; Braga, Valdeilson S.; Barros, Ivoneide de C.L.

2015-01-01

Graphical abstract: - Highlights: • Adsorbents based in RHA modified with niobium were prepared by impregnation. • The impregnation modified the particle size and topology of RHA particles. • The adsorbents were applied in sulfur removal in model liquid fuels. • The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% niobium oxide. • The adsorbent show great selectivity in adsorption experiments. - Abstract: Adsorbents based in rice husk ash (RHA) modified with niobium pentoxide were prepared for impregnation methods and applied in sulfur removal in liquid fuels. The solids were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption and thermal analysis; they show that there was no qualitative change in the amorphous structure of the RHA; however, the method of impregnation could modify the particle size and topology of RHA particles. The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% Nb 2 O 5 at a dosage of 10 g L −1 , after 4 h of contact with the model fuel. The kinetic study of adsorption of thiophene showed that the models of pseudo-second order and intra-particle diffusion best fit the experimental data. The adsorption experiments with the thiophenic derivatives compounds show a large selectivity of the adsorbent.

Adsorption of sulfur compound utilizing rice husk ash modified with niobium

Energy Technology Data Exchange (ETDEWEB)

Cavalcanti, Rodrigo M.; Pessoa Júnior, Wanison A.G. [Laboratório de Catálise Química e Materiais (CATAMA), Instituto de Ciências Exatas, Universidade Federal do Amazonas (UFAM), Av. Gen. Rodrigo Otávio Jordão Ramos, 6200, 69077-000 Manaus, AM (Brazil); Braga, Valdeilson S. [Laboratório de Catálise, Centro das Ciências Exatas e das Tecnologias, Universidade Federal do Oeste da Bahia, Rua Professor José Seabra de Lemos, 316, Recanto dos Pássaros, 47808-021 Barreira, BA (Brazil); Barros, Ivoneide de C.L., E-mail: iclbarros@gmail.com [Laboratório de Catálise Química e Materiais (CATAMA), Instituto de Ciências Exatas, Universidade Federal do Amazonas (UFAM), Av. Gen. Rodrigo Otávio Jordão Ramos, 6200, 69077-000 Manaus, AM (Brazil)

2015-11-15

Graphical abstract: - Highlights: • Adsorbents based in RHA modified with niobium were prepared by impregnation. • The impregnation modified the particle size and topology of RHA particles. • The adsorbents were applied in sulfur removal in model liquid fuels. • The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% niobium oxide. • The adsorbent show great selectivity in adsorption experiments. - Abstract: Adsorbents based in rice husk ash (RHA) modified with niobium pentoxide were prepared for impregnation methods and applied in sulfur removal in liquid fuels. The solids were characterized by X-ray diffraction, infrared spectroscopy, scanning electron microscopy, nitrogen physisorption and thermal analysis; they show that there was no qualitative change in the amorphous structure of the RHA; however, the method of impregnation could modify the particle size and topology of RHA particles. The larger sulfur removal (>50%) was achieved using RHA with 5 wt.% Nb{sub 2}O{sub 5} at a dosage of 10 g L{sup −1}, after 4 h of contact with the model fuel. The kinetic study of adsorption of thiophene showed that the models of pseudo-second order and intra-particle diffusion best fit the experimental data. The adsorption experiments with the thiophenic derivatives compounds show a large selectivity of the adsorbent.

GCMS investigation of volatile compounds in green coffee affected by potato taste defect and the Antestia bug.

Science.gov (United States)

Jackels, Susan C; Marshall, Eric E; Omaiye, Angelica G; Gianan, Robert L; Lee, Fabrice T; Jackels, Charles F

2014-10-22

Potato taste defect (PTD) is a flavor defect in East African coffee associated with Antestiopsis orbitalis feeding and 3-isopropyl-2-methoxypyrazine (IPMP) in the coffee. To elucidate the manifestation of PTD, surface and interior volatile compounds of PTD and non-PTD green coffees were sampled by headspace solid phase microextraction and analyzed by gas chromatography mass spectrometry. Principal component analysis of the chromatographic data revealed a profile of surface volatiles distinguishing PTD from non-PTD coffees dominated by tridecane, dodecane, and tetradecane. While not detected in surface volatiles, IPMP was found in interior volatiles of PTD coffee. Desiccated antestia bugs were analyzed by GCMS, revealing that the three most prevalent volatiles were tridecane, dodecane, and tetradecane, as was found in the surface profile PTD coffee. Coffee having visible insect damage exhibited both a PTD surface volatile profile and IPMP in interior volatiles, supporting the hypothesis linking antestia bug feeding activity with PTD profile compounds on the surface and IPMP in the interior of the beans.

Efficacy of HOCl scavenging by sulfur-containing compounds: antioxidant activity of glutathione disulfide?

NARCIS (Netherlands)

den Hartog, G.J.M.; Haenen, G.R.M.M.; Vegt, E.; van der Vijgh, W.J.F.; Bast, A.

2002-01-01

Efficacy of HOCl scavenging by sulfur-containing compounds: antioxidant activity of glutathione disulfide? den Hartog GJ, Haenen GR, Vegt E, van der Vijgh WJ, Bast A. Department of Pharmacology and Toxicology, Maastricht University, The Netherlands. Hypochlorous acid (HOCl) is a bactericidal

Volatile compounds from leaves of the African spider plant (Gynandropsis gynandra) with bioactivity against spider mite (Tetranychus urticae)

DEFF Research Database (Denmark)

Nyalala, Samuel Odeyo; Petersen, Mikael Agerlin; Grout, Brian William Wilson

2013-01-01

Previous studies have demonstrated that Gynandropsis gynandra emits acetonitrile as a foliar volatile from intact plants and isolated leaves, and that this compound is an effective spider mite repellent. This study has used gas chromatography–mass spectrometry to investigate volatile compounds...... emitted from homogenised G. gynandra leaves to evaluate their tissue acetonitrile content and to look for other compounds that might be exploited for the management of spider mites. Acetonitrile was absent from the homogenised tissues of five lines of G. gynandra, studied over two seasons. Thirteen...... volatile compounds were emitted by G. gynandra at significantly higher levels than mite-susceptible pot roses, including isothiocyanates, aldehydes, esters, alcohols and terpenes. Six representative compounds were selected to assess bioactivity. Spider mite populations were completely inactive after a 2¿h...

Factors that influence the volatile organic compound content in human breath

NARCIS (Netherlands)

Blanchet, L.; Smolinska, Agnieszka; Baranska, Agnieszka; Tigchelaar-Feenstra, E.; Swertz, M.; Zhernakova, A.; Dallinga, J. W.; Wijmenga, C.; van Schooten, Frederik J.

Background. Thousands of endogenous and exogenous volatile organic compounds (VOCs) are excreted in each breath. Inflammatory and deviant metabolic processes affect the level of endogeneous VOCs, which can serve as specific biomarkers for clinical diagnosis and disease monitoring. Important issues

Electrospun Polyurethane Fibers for Absorption of Volatile Organic Compounds from Air

NARCIS (Netherlands)

Scholten, E.; Bromberg, L.; Rutledge, G.C.; Hatton, T.A.

2011-01-01

Electrospun polyurethane fibers for removal of volatile organic compounds (VOC) from air with rapid VOC absorption and desorption have been developed. Polyurethanes based on 4,4-methylenebis(phenylisocyanate) (MDI) and aliphatic isophorone diisocyanate as the hard segments and butanediol and

Biological relevance of volatile organic compounds emitted during the pathogenic interactions between apple plants and Erwinia amylovora.

Science.gov (United States)

Cellini, Antonio; Buriani, Giampaolo; Rocchi, Lorenzo; Rondelli, Elena; Savioli, Stefano; Rodriguez Estrada, Maria T; Cristescu, Simona M; Costa, Guglielmo; Spinelli, Francesco

2018-01-01

Volatile organic compounds emitted during the infection of apple (Malus pumila var. domestica) plants by Erwinia amylovora or Pseudomonas syringae pv. syringae were studied by gas chromatography-mass spectrometry and proton transfer reaction-mass spectrometry, and used to treat uninfected plants. Infected plants showed a disease-specific emission of volatile organic compounds, including several bio-active compounds, such as hexenal isomers and 2,3-butanediol. Leaf growth promotion and a higher resistance to the pathogen, expressed as a lower bacterial growth and migration in plant tissues, were detected in plants exposed to volatile compounds from E. amylovora-infected plants. Transcriptional analysis revealed the activation of salicylic acid synthesis and signal transduction in healthy plants exposed to volatiles produced by E. amylovora-infected neighbour plants. In contrast, in the same plants, salicylic acid-dependent responses were repressed after infection, whereas oxylipin metabolism was activated. These results clarify some metabolic and ecological aspects of the pathogenic adaptation of E. amylovora to its host. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Oceanic Emissions and Atmospheric Depositions of Volatile Organic Compounds

Science.gov (United States)

Yang, M.; Blomquist, B.; Beale, R.; Nightingale, P. D.; Liss, P. S.

2015-12-01

Atmospheric volatile organic compounds (VOCs) affect the tropospheric oxidative capacity due to their ubiquitous abundance and relatively high reactivity towards the hydroxyal radical. Over the ocean and away from terrestrial emission sources, oxygenated volatile organic compounds (OVOCs) make up a large fraction of VOCs as airmasses age and become more oxidized. In addition to being produced or destroyed in the marine atmosphere, OVOCs can also be emitted from or deposited to the surface ocean. Here we first present direct air-sea flux measurements of three of the most abundant OVOCs - methanol, acetone, and acetaldehyde, by the eddy covariance technique from two cruises in the Atlantic: the Atlantic Meridional Transect in 2012 and the High Wind Gas Exchange Study in 2013. The OVOC mixing ratios were quantified by a high resolution proton-reaction-transfer mass spectrometer with isotopically labeled standards and their air-sea (net) fluxes were derived from the eddy covariance technique. Net methanol flux was consistently from the atmosphere to the surface ocean, while acetone varied from supersaturation (emission) in the subtropics to undersaturation (deposition) in the higher latitudes of the North Atlantic. The net air-sea flux of acetaldehyde is near zero through out the Atlantic despite the apparent supersaturation of this compound in the surface ocean. Knowing the dissolved concentrations and in situ production rates of these compounds in seawater, we then estimate their bulk atmospheric depositions and oceanic emissions. Lastly, we summarize the state of knowledge on the air-sea transport of a number of organic gasses, and postulate the magnitude and environmental impact of total organic carbon transfer between the ocean and the atmosphere.

Identification of volatile compound markers during the ripening and senescence of lulo (Solanum quitoense Lam.).

Science.gov (United States)

Corpas Iguarán, Eduardo; Taborda Ocampo, Gonzalo; Tapasco Alzate, Omar

2018-01-01

Lulo ( Solanum quitoense Lam.) is an exotic fruit cultivated in Colombia. During ripening and senescence, this climactic fruit undergoes biochemical processes that produce the volatiles responsible for its aroma. This study aimed to evaluate the changes in the volatile content during the ripening and senescence of lulo. Analysis of the volatile composition of lulo harvested in each of its five ripening stages and during its senescence time when stored at 18 ± 2 °C was performed using HS-SPME with GC-MS. Throughout ripening, the most notable change was the transformation of alcohols such as (Z)-3-hexen-1-ol and 1-penten-3-ol to afford esters such as (Z)-3-hexenyl acetate and ketones such as 1-penten-3-one. Some acids reacted with alcohols to produce acetate and hexanoate esters, concentrations which increased more than sixfold between stage one and five. Moreover, all the major compounds were C 6 straight chain compounds related to the lipoxygenase pathway. During senescence, majority of compounds were methyl esters, which increased in concentration consistently until day eight. Remarkably, the content of methyl butanoate increased from 0.9% of the total amount of volatiles on day two up to 76.4% on day eight. Some of these volatiles are probably contributors to the "off flavor" during senescence.

Determination of non-volatile radiolytic compounds in ethylene co-vinyl alcohol

International Nuclear Information System (INIS)

Kothapalli, A.; Sadler, G.

2003-01-01

The use of ionizing radiation on food contact polymers is increasing due to the critical role of the package in holding or containing the irradiated foods [Food Add. Contam. 18(6) (2001) 475]. Irradiation benefits the food if properly applied and the food is pre-packaged prior to irradiation to protect it from subsequent recontamination. The United States Food and Drug Administration (USFDA) has approved the use of ionizing radiation within the dosage range of 0-60 kGy on limited films since the 1960s [USFDA 21CFR 179.45]. The obstacle in the way of approval of additional polymers is that FDA fears that these materials may undergo changes during irradiation producing toxic radiolytic fragments. Ethylene co-vinyl alcohol (EVOH), which is often used in food applications, is not approved by the FDA for pre-packaged irradiated foods. The present work examines the non-volatile radiolytic compounds, which may be formed due to exposure to gamma irradiation at the dosage levels of 3 and 10 kGy versus a non-radiated control. Irradiated EVOH is subjected to extraction with 95:5 ethanol and water (by volume) as the food simulating solvent (FSS) for a period of 10 days at 40 deg. C, which models the amount of radiolytic compound a food would extract in 1 year [USFDA Chemistry Requirement for Food Contact Notification]. The FSS is then analyzed for the presence of non-volatile compounds using advanced liquid chromatographic techniques. The chromatograms obtained from different dosages show that non-volatile radiolytic compounds are not formed in EVOH and it would, therefore be in compliance with safety demands of USFDA [Available at: http://www.cfsan.fda.gov/~dms/opa-guid.htmlref and http://www.access.gpo.gov/nara/cfr/cfr-table-search.htmlpage1

Determination of non-volatile radiolytic compounds in ethylene co-vinyl alcohol

Science.gov (United States)

Kothapalli, A.; Sadler, G.

2003-08-01

The use of ionizing radiation on food contact polymers is increasing due to the critical role of the package in holding or containing the irradiated foods [Food Add. Contam. 18(6) (2001) 475]. Irradiation benefits the food if properly applied and the food is pre-packaged prior to irradiation to protect it from subsequent recontamination. The United States Food and Drug Administration (USFDA) has approved the use of ionizing radiation within the dosage range of 0-60 kGy on limited films since the 1960s [USFDA 21CFR 179.45]. The obstacle in the way of approval of additional polymers is that FDA fears that these materials may undergo changes during irradiation producing toxic radiolytic fragments. Ethylene co-vinyl alcohol (EVOH), which is often used in food applications, is not approved by the FDA for pre-packaged irradiated foods. The present work examines the non-volatile radiolytic compounds, which may be formed due to exposure to gamma irradiation at the dosage levels of 3 and 10 kGy versus a non-radiated control. Irradiated EVOH is subjected to extraction with 95:5 ethanol and water (by volume) as the food simulating solvent (FSS) for a period of 10 days at 40 °C, which models the amount of radiolytic compound a food would extract in 1 year [USFDA Chemistry Requirement for Food Contact Notification]. The FSS is then analyzed for the presence of non-volatile compounds using advanced liquid chromatographic techniques. The chromatograms obtained from different dosages show that non-volatile radiolytic compounds are not formed in EVOH and it would, therefore be in compliance with safety demands of USFDA [Available at: http://www.cfsan.fda.gov/~dms/opa-guid.html#ref and http://www.access.gpo.gov/nara/cfr/cfr-table-search.html#page1].

Comparison of two common adsorption materials for thermal desorption gas chromatography - mass spectrometry of biogenic volatile organic compounds.

Science.gov (United States)

Marcillo, Andrea; Jakimovska, Viktorija; Widdig, Anja; Birkemeyer, Claudia

2017-09-08

Volatile organic compounds (VOCs) are commonly collected from gaseous samples by adsorption to materials such as the porous polymer Tenax TA. Adsorbed compounds are subsequently released from these materials by thermal desorption (TD) and separated then by gas chromatography (GC) with flame ionization (FID) or mass spectrometry (MS) detection. Tenax TA is known to be particularly suitable for non-polar to semipolar volatiles, however, many volatiles from environmental and biological samples possess a rather polar character. Therefore, we tested if the polymer XAD-2, which so far is widely used to adsorb organic compounds from aqueous and organic solvents, could provide a broader coverage for (semi)polar VOCs during gas-phase sampling. Mixtures of volatile compounds covering a wide range of volatility (bp. 20-256°C) and different chemical classes were introduced by liquid spiking into sorbent tubes with one of the two porous polymers, Tenax TA or XAD-2, and analyzed by TD/GC-MS. At first, an internal standard mixture composed of 17 authentic standards was used to optimize desorption temperature with respect to sorbent degradation and loading time for calibration. Secondly, we tested the detectability of a complex standard mixture composed of 57 volatiles, most of them common constituents of the body odor of mammals. Moreover, the performance of XAD-2 compared with Tenax TA was assessed as limit of quantitation and linearity for the internal standard mixture and 33 compounds from the complex standard mixture. Volatiles were analyzed in a range between 0.01-∼250ng/tube depending on the compound and material. Lower limits of quantitation were between 0.01 and 3 ng±0.9). Interestingly, we found different kinetics for compound adsorption with XAD-2, and a partially better sensitivity in comparison with Tenax TA. For these analytes, XAD-2 might be recommended as an alternative of Tenax TA for TD/GC-MS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Microbial communities related to volatile organic compound emission in automobile air conditioning units.

Science.gov (United States)

Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

2013-10-01

During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded.

Characterization of Volatile Compounds with HS-SPME from Oxidized n-3 PUFA Rich Oils via Rancimat Tests.

Science.gov (United States)

Yang, Kai-Min; Cheng, Ming-Ching; Chen, Chih-Wei; Tseng, Chin-Yin; Lin, Li-Yun; Chiang, Po-Yuan

2017-02-01

Algae oil and fish oil are n-3 PUFA mainstream commercial products. The various sources for the stability of n-3 PUFA oxidation are influenced by the fatty acid composition, extraction and refined processing. In this study, the oil stability index (OSI) occurs within 2.3 to 7.6 hours with three different n-3 PUFA rich oil. To set the OSI in the Rancimat test as the oil stability limit and observed various degrees of oxidation (0, 25, 50, 75, 100 and 125%). The volatile oxidation compounds were analyzed via headspace-solid phase microextraction (HS-SPME) and GC/MS. We detected 51 volatile compound variations during the oxidation, which were composed of aldehydes, hydrocarbons, cyclic compounds, alcohols, benzene compounds, ketones, furans, ester and pyrrolidine. The off-flavor characteristics can be strongly influenced by the synergy effects of volatile oxidation compounds. Chemometric analysis (PCA and AHC) was applied to identify the sensitive oxidation marker compounds, which included a (E,E)-2,4-heptadienal appropriate marker, via lipid oxidation in the n-3 PUFA rich oil.

Effect of hot air drying on volatile compounds of Flammulina velutipes detected by HS-SPME-GC-MS and electronic nose.

Science.gov (United States)

Yang, Wenjian; Yu, Jie; Pei, Fei; Mariga, Alfred Mugambi; Ma, Ning; Fang, Yong; Hu, Qiuhui

2016-04-01

Volatile compounds are important factors that affect the flavor quality of Flammulina velutipes, but the changes occurring during hot air drying is still unclear. To clarify the dynamic changes of flavor components during hot air drying, comprehensive flavor characterization and volatile compounds of F. velutipes were evaluated using electronic nose technology and headspace solid phase micro-extraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS), respectively. Results showed that volatile components in F. velutipes significantly changed during hot air drying according to the principal component analysis and radar fingerprint chart of electronic nose. Volatile compounds of fresh F. velutipes consisted mainly of ketones, aldehydes and alcohols, and 3-octanone was the dominant compound. Drying process could significantly decrease the relative content of ketones and promoted the generation of alcohols, acids, and esters, which became the main volatile compounds of dried F. velutipes. These may provide a theoretical basis for the formation mechanism of flavor substances in dried F. velutipes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Development of techniques of production of sulfur-35 and its inorganic compounds

International Nuclear Information System (INIS)

Shikata, Eiji

1981-12-01

Techniques to produce routinely Curies of carrier-free sulfur-35 from neutron irradiated potassium chloride were developed. Firstly the ratio of sulfur-35 to phosphorus-32 produced respectively by the reactions 35 Cl(n,p) 35 S and 35 Cl(n,α) 32 P was determined. For the post-irradiation process, two processes of anion exchange and cation exchange were studied. The former process was based on the selective elution of carrier-free sulfate after precipitation of the bulk of potassium chloride by ethanol and the latter process on the selective adsorption of carrier-free phosphate on Fe +3 -cation exchange resin. A gloved box with various appendant equipments was constructed for routine production and a glass apparatus was installed in it. Sulfur-35 from 1 Ci to 5 Ci has been produced by the cation exchange process several times every year during past few years, and products of high quality have been obtained with yields higher than 90% without any troubles. In the studies on the synthesis of sulfur-35 labeled inorganic compounds, sulfate[ 35 S] was reduced with tin(II)-phosphoric acid to hydrogen sulfide[ 35 S], which was oxidized to elementary sulfur[ 35 S]. Sulfate[ 35 S] of sodium or copper(II) was precipitated from an aqueous solution of sodium or copper(II) chloride containing carrier-free sulfate [ 35 S] by adding carrier of either one of the sulfates and ethanol. Copper(II) sulfate[ 35 S] was pyrolyzed to evolve sulfur[ 35 S] dioxide, which was fixed in a sodium hydroxide solution as sodium sulfite[ 35 S]. This was allowed to react with colloidal sulfur in a boiling solution in the presence of 2-octanol to form thiosulfate[ 35 S] efficiently. By treating target potassium chloride before and after irradiation in an oxygen-free atmosphere, approximately 60% of sulfur-35 was recovered as thiosulfate. Reduction with nascent hydrogen and decomposition with acid of the thiosulfate were studied to prepare elementary sulfur [ 35 S]. (author)

Sensory and volatile profiles of monofloral honeys produced by native stingless bees of the brazilian semiarid region.

Science.gov (United States)

Costa, Ana Caroliny Vieira da; Sousa, Janaína Maria Batista; da Silva, Maria Aparecida Azevedo Pereira; Garruti, Deborah Dos Santos; Madruga, Marta Suely

2018-03-01

Monofloral honeys produced by stingless bees M. subnitida Ducke and M. scutellaris Latrelle in typical flowering of the Brazilian semi-arid Ziziphus juazeiro Mart (juazeiro), Croton heliotropiifolius Kunth (velame branco) and Mimosa arenosa willd Poir (jurema branca) were characterized in relation to volatile and sensorial profile. It identified 11 sensory descriptors and 96 volatile compounds. It was noticed a strong effect of flowering in sensorial profile and volatile of honeys. Juazeiro honey stood out with a higher characteristic aroma, taste sweet, caramel flavor and levels of aromatic aldehydes; jurema honey has been described with herb and beeswax aroma and the presence of sulfur compounds and ketones; volatile acids associated with acid taste, medicinal taste and clove aroma characterized the velame branco honey. These results demonstrate that the knowledge of the sensory and aroma profile of these honeys can contribute to characterization of its floral and geographical identity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Volatile and intermediate volatility organic compounds in suburban Paris: variability, origin and importance for SOA formation

International Nuclear Information System (INIS)

Ait-Helal, W.; Borbon, A.; Beekmann, M.; Doussin, J.F.; Durand-Jolibois, R.; Grand, N.; Michoud, V.; Miet, K.; Perrier, S.; Siour, G.; Zapf, P.; Sauvage, S.; Fronval, I.; Leonardis, T.; Locoge, N.; Gouw, J.A. de; Colomb, A.; Gros, V.; Lopez, M.

2014-01-01

Measurements of gaseous and particulate organic carbon were performed during the MEGAPOLI experiments, in July 2009 and January-February 2010, at the SIRTA observatory in suburban Paris. Measurements comprise primary and secondary volatile organic compounds (VOCs), of both anthropogenic and biogenic origins, including C12-C16 n-alkanes of intermediate volatility (IVOCs), suspected to be efficient precursors of secondary organic aerosol (SOA). The time series of gaseous carbon are generally consistent with times series of particulate organic carbon at regional scale, and are clearly affected by meteorology and air mass origin. Concentration levels of anthropogenic VOCs in urban and suburban Paris were surprisingly low (2-963 ppt) compared to other mega-cities worldwide and to rural continental sites. Urban enhancement ratios of anthropogenic VOC pairs agree well between the urban and suburban Paris sites, showing the regional extent of anthropogenic sources of similar composition. Contrary to other primary anthropogenic VOCs (aromatics and alkanes), IVOCs showed lower concentrations in winter (≤ 5 ppt) compared to summer (13-27 ppt), which cannot be explained by the gas-particle partitioning theory. Higher concentrations of most oxygenated VOCs in winter (18-5984 ppt) suggest their dominant primary anthropogenic origin. The respective role of primary anthropogenic gaseous compounds in regional SOA formation was investigated by estimating the SOA mass concentration expected from the anthropogenic VOCs and IVOCs (I/VOCs) measured at SIRTA. From an integrated approach based on emission ratios and SOA yields, 38% of the SOA measured at SIRTA is explained by the measured concentrations of I/VOCs, with a 2% contribution by C12-C16 n-alkane IVOCs. From the results of an alternative time-resolved approach, the average IVOC contribution to SOA formation is estimated to be 7 %, which is half of the average contribution of the traditional aromatic compounds (15 %). Both

Total Oxidation of Model Volatile Organic Compounds over Some Commercial Catalysts

Czech Academy of Sciences Publication Activity Database

Matějová, Lenka; Topka, Pavel; Jirátová, Květa; Šolcová, Olga

2012-01-01

Roč. 443, NOV 7 (2012), s. 40-49 ISSN 0926-860X R&D Projects: GA MPO FR-TI1/059 Institutional support: RVO:67985858 Keywords : volatile organic compounds * oxidation * ethanol Subject RIV: DM - Solid Waste and Recycling Impact factor: 3.410, year: 2012

Possibility of use of Azgir underground nuclear cavities for burial of sulfur and her toxic compounds - products of oil refining

International Nuclear Information System (INIS)

Akhmetov, E.Z.; Adymov, Zh.I.

1998-01-01

The intensive growth of production oil and gas in Western Kazakhstan increases ecological vulnerability of an environment and a fauna because of the pressure of negative consequences arising with production, refining and transportation of the oil raw material, and also because of pernicious influence of accompanying products and wastes of oil refining manufacture being chemically dangerous and toxic, requiring special conditions of the handling, warehousing and storage for provision of ecological safety. A problem of the reclamation, safe warehousing, storage and long-term disposal (burial) of such accompanying products and wastes, as for example, sulfur and its compounds till now is not solved. For example, the mass of the accumulated mountains of crystal sulfur makes on cautious calculations from 2 up to 3 million tonnes also creates real danger of the propagation and harmful influence on the environment. The neutralization of sulfur and its compounds means removal them from the active handling with an environment, i.e. creation of such conditions in which sulfur products for a long time cannot cause harm atmosphere, underground medium and waters, vegetative and animal world. For it is offered to use underground cavities in a salt dome raising Large Azgir and the funnel-shaped hollow in persalt rocks formed as a result of underground nuclear explosions, carried out in 1978-1979 years near village Azgir Atyrau province. The sulfur products is possible to place on a long safe storage in funnel-shaped hollow (the A9 platform) volume 1,5 million cubic meters, by keeping, if necessary, an possibility of their extraction for needs of the future generations or to remove in underground nuclear cavities in stone salt (the A8 and A11 platforms) total volume 330000 cubic meters, from which it is not provided in the future to take out the sulfur products. At this the sulfur is removed from an environment on a storage or burial in the inactive form, i.e. the sulfur products

Marine Vibrio Species Produce the Volatile Organic Compound Acetone

OpenAIRE

Nemecek-Marshall, M.; Wojciechowski, C.; Kuzma, J.; Silver, G. M.; Fall, R.

1995-01-01

While screening aerobic, heterotrophic marine bacteria for production of volatile organic compounds, we found that a group of isolates produced substantial amounts of acetone. Acetone production was confirmed by gas chromatography, gas chromatography-mass spectrometry, and high-performance liquid chromatography. The major acetone producers were identified as nonclinical Vibrio species. Acetone production was maximal in the stationary phase of growth and was stimulated by addition of l-leucine...

Emissions of Volatile Organic Compounds (VOCs) from Animal Husbandry: Chemical Compositions, Separation of Sources and Animal Types

Science.gov (United States)

Yuan, B.; Coggon, M.; Koss, A.; Warneke, C.; Eilerman, S. J.; Neuman, J. A.; Peischl, J.; Aikin, K. C.; Ryerson, T. B.; De Gouw, J. A.

2016-12-01

Concentrated animal feeding operations (CAFOs) are important sources of volatile organic compounds (VOCs) in the atmosphere. We used a hydronium ion time-of-flight chemical ionization mass spectrometer (H3O+ ToF-CIMS) to measure VOC emissions from CAFOs in the Northern Front Range of Colorado during an aircraft campaign (SONGNEX) for regional contributions and from a mobile laboratory sampling for chemical characterizations of individual animal feedlots. The main VOCs emitted from CAFOs include carboxylic acids, alcohols, carbonyls, phenolic species, sulfur- and nitrogen-containing species. Alcohols and carboxylic acids dominate VOC concentrations. Sulfur-containing and phenolic species become more important in terms of odor activity values and NO3 reactivity, respectively. The high time-resolution mobile measurements allow the separation of the sources of VOCs from different parts of the operations occurring within the facilities. We show that the increase of ethanol concentrations were primarily associated with feed storage and handling. We apply a multivariate regression analysis using NH3 and ethanol as tracers to attribute the relative importance of animal-related emissions (animal exhalation and waste) and feed-related emissions (feed storage and handling) for different VOC species. Feed storage and handling contribute significantly to emissions of alcohols, carbonyls and carboxylic acids. Phenolic species and nitrogen-containing species are predominantly associated with animals and their waste. VOC ratios can be potentially used as indicators for the separation of emissions from dairy and beef cattle from the regional aircraft measurements.

In situ extraction and analysis of volatiles and simple molecules in interplanetary dust particles, contaminants, and silica aerogel

Science.gov (United States)

Hartmetz, C. P.; Gibson, E. K., Jr.; Blanford, G. E.

1990-01-01

Results are presented for the analyses of eight interplanetary dust particles (IDPs) for the volatile elements H, C, N, O, and S and their molecular species, as well as of the volatiles associated with contaminants (i.e., the compounds used during the collection and curation of IDPs), which were carried out using a laser microprobe interfaced with a quadrupole mass spectrometer. It was found that the volatile species from contaminants were always present in the spectra of IDPs. Despite the contamination problems, several indigenous molecular species could be identified, including OH, CO2 or C2H4, C and CS2, CO2 along with CO (possibly indicating the presence of carbonate), H2S, SO, COS, SO2, and CS2. In some cases, the sulfur components can be attributed to aerosols; however, in one of the IDPs, the presence of H2S, SO, COS, and SO2 indicates the possible presence of elemental sulfur.

Comparison of the neurotoxicities between volatile organic compounds and fragrant organic compounds on human neuroblastoma SK-N-SH cells and primary cultured rat neurons

Directory of Open Access Journals (Sweden)

Yasue Yamada

2015-01-01

Full Text Available These are many volatile organic compounds (VOCs that are synthesized, produced from petroleum or derived from natural compounds, mostly plants. Fragrant and volatile organic compounds from plants have been used as food additives, medicines and aromatherapy. Several clinical and pathological studies have shown that chronic abuse of VOCs, mainly toluene, causes several neuropsychiatric disorders. Little is known about the mechanisms of neurotoxicity of the solvents. n-Octanal, nonanal, and 2-ethyl-1-hexanol, which are used catalyzers or intermediates of chemical reactions, are released into the environment. Essential oils have the functions of self-defense, sterilization, and antibiosis in plants. When volatile organic compounds enter the body, there is the possibility that they will pass through the blood–brain barrier (BBB and affect the central nervous system (CNS. However, the direct effects of volatile organic compounds on neural function and their toxicities are still unclear. We compared the toxicities of n-octanal, nonanal and 2-ethyl-1-hexanol with those of five naturally derived fragrant organic compounds (FOCs, linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and n-phenethyl alcohol. MTT assay of human neuroblastoma SK-N-SH cells showed that the IC50 values of linalool, cis-3-hexen-1-ol, isoamyl alcohol, n-propyl alcohol and phenethyl alcohol were 1.33, 2.3, >5, >5, and 2.39 mM, respectively, and the IC50 values of toluene, n-octanal, nonanal and 2-ethyl-1-hexanol were 850, 37.2, 8.31 and 15.1 μM, respectively. FOCs showed lower toxicities than those of VOCs. These results indicate that FOCs are safer than other compounds.

A Simplified Model for Volatile-N Oxidation

DEFF Research Database (Denmark)

Hansen, Stine; Glarborg, Peter

2010-01-01

In solid fuel flames, NO is largely formed from the oxidation of volatile nitrogen compounds such as HCN and NH3. To be able to model the nitrogen chemistry in these flames, it is necessary to have an adequate model for volatile-N oxidation. Simple global models for oxidation of HCN and NH3 from...... the literature should be used cautiously, since their predictive capabilities are limited, particularly under reducing conditions. Models for HCN/NH3/NO conversion based on the systematic reduction of a detailed chemical kinetic model offer high accuracy but rely on input estimates of combustion intermediates...... for the sub-bituminous and bituminous coals, especially at lower temperatures. The semiempirical correlations for estimating radical concentrations may also be useful in combination with models for other trace species, such as sulfur oxides, organic species, etc....

The scent of colorectal cancer: detection by volatile organic compound analysis

NARCIS (Netherlands)

de Boer, Nanne K. H.; de Meij, Tim G. J.; Oort, Frank A.; Ben Larbi, Ilhame; Mulder, Chris J. J.; van Bodegraven, Adriaan A.; van der Schee, Marc P.

2014-01-01

The overall metabolic state of an individual is reflected by emitted volatile organic compounds (VOCs), which are gaseous carbon-based chemicals. In this review, we will describe the potential of VOCs as fully noninvasive markers for the detection of neoplastic lesions of the colon. VOCs are

Control of postharvest Botrytis fruit rot of strawberry by volatile organic compounds of Candida intermedia.

Science.gov (United States)

Huang, R; Li, G Q; Zhang, J; Yang, L; Che, H J; Jiang, D H; Huang, H C

2011-07-01

A study was conducted to identify volatile organic compounds or volatiles produced by Candida intermedia strain C410 using gas chromatography-mass spectrometry, and to determine efficacy of the volatiles of C. intermedia in suppression of conidial germination and mycelial growth of Botrytis cinerea and control of Botrytis fruit rot of strawberry. Results showed that, among 49 volatiles (esters, alcohols, alkenes, alkanes, alkynes, organic acids, ketones, and aldehydes) identified from C. intermedia cultures on yeast extract peptone dextrose agar, two compounds, 1,3,5,7-cyclooctatetraene and 3-methyl-1-butanol, were the most abundant. Synthetic chemicals of 1,3,5,7-cyclooctatetraene; 3-methyl-1-butanol; 2-nonanone; pentanoic acid, 4-methyl-, ethyl ester; 3-methyl-1-butanol, acetate; acetic acid, pentyl ester; and hexanoic acid, ethyl ester were highly inhibitory to conidial germination and mycelial growth of B. cinerea. Inhibition of conidial germination and mycelial growth of B. cinerea by volatiles of C. intermedia was also observed. Meanwhile, results showed that incidence and severity of Botrytis fruit rot of strawberry was significantly (P intermedia cultures or C. intermedia-infested strawberry fruit. These results suggest that the volatiles of C. intermedia C410 are promising biofumigants for control of Botrytis fruit rot of strawberry.

Volatile organic compounds emissions from gasoline and diesel powered vehicle

Energy Technology Data Exchange (ETDEWEB)

Mugica, V [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico); Vega, E; Sanchez, G; Reyes, E; Arriaga, J. L [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Chow, J; Watson, J; Egami, R [Desert Research Institute, Reno, NV (United States)

2001-01-01

In this research, volatile organic compound emissions were characterized from gasoline and diesel vehicles. Sampling campaigns in the Metropolitan Area of Mexico City were designed and carried out in tunnels, crossroads, and truck and bus terminals. The samples were analyzed with gas chromatography getting more than 250 different compounds, being more or less 60 of them the 80% of all the emissions. The most abundant are the two carbon compounds, as a result of the combustion, and compounds related to fuels compositions, like isopentane, xylenes, toluene among others. The profiles obtained in tunnels and crossroads were very similar with the exception of the 3 and 4 carbon compounds, which were found in bigger proportion in the profiles at crossroads. This may probably be due to the blend with the ambient air. The profiles corresponding to trucks and buses have a smaller content of two carbon compounds and a bigger content of xylenes, toluene and ethylbenzene. The variations in the proportions of the compounds allow differentiating the profiles of vehicles using gasoline and diesel. [Spanish] En este trabajo se caracterizaron las emisiones de compuestos organicos volatiles provenientes de vehiculos a gasolina y a diesel. Para ello, se disenaron diversas campanas de muestreo en la zona Metropolitana de la Ciudad de Mexico, en tuneles, cruceros y estaciones de camiones de carga y autobuses. Las muestras se analizaron con cromatografia, de gases obteniendose mas de 250 compuestos distintos, de los cuales aproximadamente 60 corresponden a mas del 80% de las emisiones. Los compuestos mas abundantes son los de dos carbonos, resultado de la combustion, y 4 carbonos que se encontraron en mayor proporcion en los perfiles de cruceros, lo cual se debe probablemente a la mezcla con el aire ambiente. Los perfiles correspondientes a camiones de carga y autobuses tienen un menor contenido de compuestos de dos carbonos y un mayor contenido de xilenos, tolueno y etilbenceno. Estas

Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development

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Yuying Li

2016-04-01

Full Text Available Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS was employed to identify the volatile organic compounds (VOCs emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%–83% followed by (E,E-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties.

Chemical protection of bacteria and cultured mammalian cells by sulfur--containing compounds

Energy Technology Data Exchange (ETDEWEB)

Antoku, S [Hiroshima Univ. (Japan). Research Inst. for Nuclear Medicine and Biology

1975-03-01

Protection by sulfur-containing compounds was studied using bacteria E. coli Bsub(H) and cultured mouse leukemic cells, L 5178 Y. The protective mechanisms are discussed. The dose reduction factors of non-sulfhydryl compounds observed in the bacteria were the same as those observed in mammalian cells, and the protective activity of these compounds was proportional to their reaction rates with hydroxyl radicals. On the other hand, sulfhydryl compounds, with the exception of glutathione, offered a much greater protection than was anticipated from their radical scavenging activity. From studies under anoxia, the protection of cysteine was explained by its OH scavenging and competition with oxygen. In addition, for MEA, protection against the direct action of radiation was suggested. This was supported by the significant protection in the frozen state.

Tentative Identification of Volatile Flavor Compounds in Commercial Budu, a Malaysian Fish Sauce, Using GC-MS

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Yazid Abdul Manap

2012-05-01

Full Text Available Budu is a famous Malaysian fish sauce, usually used as seasoning and condiment in cooking. Budu is produced by mixing fish and salt at certain ratio followed by fermentation for six months in closed tanks. In this study, four commercial brands of Budu were analyzed for their chemical properties (pH, salt content and volatile compounds. The pH of Budu samples ranged from 4.50–4.92, while the salt (NaCl content ranged between 11.80% and 22.50% (w/v. For tentative identification of volatile flavor compounds in Budu, two GC columns have been used, DB-WAX and HP-5MS. A total of 44 volatile compounds have been detected and 16 were common for both columns. 3-Methyl-1-butanol, 2-methylbutanal, 3-methylbutanal, dimethyl disulfide, 3-(methylthio-propanal, 3-methylbutanoic acid and benzaldehye have been identified as the aroma-active compounds in Budu due to their lower threshold values.

Combinatorial synthesis by nature: volatile organic sulfur-containing constituents of Ruta chalepensis L.

Science.gov (United States)

Escher, Sina; Niclass, Yvan; van de Waal, Matthijs; Starkenmann, Christian

2006-09-01

Ongoing interest in discovering new natural fragrance and flavor ingredients prompted us to examine a solvent extract of sulfurous-sweaty smelling Ruta chalepensis L. (Rutaceae) plant material more closely. Twenty-one sulfur-containing constituents of similar structures were identified by GC/MS techniques. Amongst them, 14 have never been described to occur in nature. The compounds 1-18 belong to a family of natural flavor and fragrance molecules having a 1,3-positioned O,S moiety in common. The identities of the natural constituents were confirmed by comparison with synthetic reference samples, and the organoleptic properties of the latter were studied. The relative and absolute configurations of the four stereoisomers of 4-methyl-3-sulfanylhexan-1-ol (5) were established by stereoselective synthesis. The natural isomers consisted of a 65 : 35 mixture of (3R,4S)-5 and (3S,4S)-5.

Extraction and GC determination of volatile aroma compounds from extracts of three plant species of the Apiaceae family

Science.gov (United States)

Stan, M.; Soran, M. L.; Varodi, C.; Lung, I.; Copolovici, L.; MǎruÅ£oiu, C.

2013-11-01

Parsley (Petroselinum crispum), dill (Anethum graveolens) and celery (Apium graveolens), three aromatic plants belonging to the Apiaceae (Umbelliferae) botanical family, were selected as sources of essential or volatile oils. Essential oils are composed of a large diversity of volatile aroma compounds. Plant-derived essential oils and extracts have long been used as natural agents in food preservation, pharmaceuticals and medicinal therapies. In the present study, the plant extracts from leaves of parsley, dill and celery, were obtained by maceration, ultrasound-assisted extraction and microwave-assisted extraction. All extractions were performed at 30°C, using different solvents (ethanol, diethyl ether, n-hexane) and solvent mixtures (1:1, v/v). The most effective solvent system for the extraction of volatile aroma compounds was diethyl ether - n-hexane (1:1, v/v). Extraction efficiency and determination of aroma volatiles were performed by GC-FID and GC-MS, respectively. The major volatile compounds present in plant extracts were myristicin, α-phellandrene, β-phellandrene, 1,3,8-p-menthatriene, apiol, dill ether and allyl phenoxyacetate.

Ammonia volatilization from coated urea forms

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Carlos Antonio Costa do Nascimento

2013-08-01

Full Text Available Nitrogen fertilization is a major component of the cost of agricultural production, due to the high cost and low efficiency of fertilizers. In the case of urea, the low efficiency is mainly due to losses by volatilization, which are more pronounced in cultivation systems in which plant residues are left on the soil. The objective of this work was to compare the influence of urea coated with sulfur or boric acid and copper sulfate with conventional N fertilizers on N volatilization losses in sugar cane harvested after stubble burning. The sources urea, sulfur-coated urea, urea coated with boric acid and copper sulfate, as well as nitrate and ammonium sulfate, were tested at amounts containing N rates of 120 kg ha-1 N. The integration of new technologies in urea fertilization can reduce N losses by volatilization. These losses were most reduced when using nitrate and ammonium sulfate. The application of a readily acidified substance (boric acid to urea was more efficient in reducing volatilization losses and nutrient removal by sugar cane than that of a substance with gradual acidification (elemental sulfur.

Dependence of Oak-Related Volatile Compounds on the Physicochemical Characteristics of Barrel-Aged Wines

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Pedro Rodríguez-Rodríguez

2012-01-01

Full Text Available This paper focuses on the effect of some of the physicochemical characteristics of wines such as volatile acidity, titratable acidity, pH, free SO2 and alcohol content on the accumulation of oak-related volatile compounds in barrel-aged wines, in order to give more light on the contradictory results found by other authors in this respect. For this, three different single variety wines were aged for twelve months in barrels with the same characteristics (same cooperage, wood origin, toasting level and volume, repeating the experiment in two consecutive years. Our results show that the percentage of wine alcohol and its titratable acidity positively correlated with the final concentration of vanillin and guaiacyl compounds in the oak-matured wines and negatively with the cis- and trans-β-methyl-γ-octalactone concentration. Therefore, when studying the effect of oak barrel variables (oak origin and seasoning, size of the barrel, number of uses, etc. on the concentration of oak-related volatile compounds in wine, the effect of the physicochemical variables of the wine, especially titratable acidity and alcohol content, should also be taken into account since the final wine aroma composition will also depend on these characteristics.

Odour Detection Threshold Determination of Volatile Compounds in Topical Skin Formulations

DEFF Research Database (Denmark)

Thomsen, Birgitte Raagaard; Hyldig, Grethe; Taylor, Robert

2018-01-01

determination and also odour description by a trained sensory panel. In one case, the odour detection threshold value was 50 times higher (less detectable) in skin care products than in water, whereas for other volatile compounds the odour detection threshold value was only 1.5 times higher. The odour...

40 CFR 60.542a - Alternate standard for volatile organic compounds.

Science.gov (United States)

2010-07-01

... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for the Rubber Tire Manufacturing Industry § 60.542a Alternate standard for volatile organic compounds. (a) On and after the date on which the initial performance test, required by § 60.8, is completed, but no...

Applications of Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry (SPME-GC/MS in the Study of Grape and Wine Volatile Compounds

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Annarita Panighel

2014-12-01

Full Text Available Volatile compounds are responsible for the wine “bouquet”, which is perceived by sniffing the headspace of a glass, and of the aroma component (palate-aroma of the overall flavor, which is perceived on drinking. Grape aroma compounds are transferred to the wine and undergo minimal alteration during fermentation (e.g., monoterpenes and methoxypyrazines; others are precursors of aroma compounds which form in winemaking and during wine aging (e.g., glycosidically-bound volatile compounds and C13-norisoprenoids. Headspace solid phase microextraction (HS-SPME is a fast and simple technique which was developed for analysis of volatile compounds. This review describes some SPME methods coupled with gas chromatography/mass spectrometry (GC/MS used to study the grape and wine volatiles.

Natural Variation of Volatile Compounds in Virgin Olive Oil Analyzed by HS-SPME/GC-MS-FID

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Carlos Sanz

2018-04-01

Full Text Available Virgin olive oil is unique among plant oils for its high levels of oleic acid, and the presence of a wide range of minor components, which are responsible for both its health-promoting properties and characteristic aroma, and only produced when olives are crushed during the industrial process used for oil production. The genetic variability of the major volatile compounds comprising the oil aroma was studied in a representative sample of olive cultivars from the World Olive Germplasm Collection (IFAPA, Cordoba, Spain, by means of the headspace solid-phase microextraction/gas chromatography–mass spectrometry–flame ionization detection (HS-SPME/GC-MS-FID. The analytical data demonstrated that a high variability is found for the content of volatile compounds in olive species, and that most of the volatile compounds found in the oils were synthesized by the enzymes included in the so-called lipoxygenase pathway. Multivariate analysis allowed the identification of cultivars that are particularly interesting, in terms of volatile composition and presumed organoleptic quality, which can be used both to identify old olive cultivars that give rise to oils with a high organoleptic quality, and in parent selection for olive breeding programs.

Description, Properties, and Degradation of Selected Volatile Organic Compounds Detected in Ground Water--A Review of Selected Literature

Science.gov (United States)

Lawrence, Stephen J.

2006-01-01

This report provides abridged information describing the most salient properties and biodegradation of 27 chlorinated volatile organic compounds detected during ground-water studies in the United States. This information is condensed from an extensive list of reports, papers, and literature published by the U.S. Government, various State governments, and peer-reviewed journals. The list includes literature reviews, compilations, and summaries describing volatile organic compounds in ground water. This report cross-references common names and synonyms associated with volatile organic compounds with the naming conventions supported by the International Union of Pure and Applied Chemistry. In addition, the report describes basic physical characteristics of those compounds such as Henry's Law constant, water solubility, density, octanol-water partition (log Kow), and organic carbon partition (log Koc) coefficients. Descriptions and illustrations are provided for natural and laboratory biodegradation rates, chemical by-products, and degradation pathways.

The life sulfuric: microbial ecology of sulfur cycling in marine sediments.

Science.gov (United States)

Wasmund, Kenneth; Mußmann, Marc; Loy, Alexander

2017-08-01

Almost the entire seafloor is covered with sediments that can be more than 10 000 m thick and represent a vast microbial ecosystem that is a major component of Earth's element and energy cycles. Notably, a significant proportion of microbial life in marine sediments can exploit energy conserved during transformations of sulfur compounds among different redox states. Sulfur cycling, which is primarily driven by sulfate reduction, is tightly interwoven with other important element cycles (carbon, nitrogen, iron, manganese) and therefore has profound implications for both cellular- and ecosystem-level processes. Sulfur-transforming microorganisms have evolved diverse genetic, metabolic, and in some cases, peculiar phenotypic features to fill an array of ecological niches in marine sediments. Here, we review recent and selected findings on the microbial guilds that are involved in the transformation of different sulfur compounds in marine sediments and emphasise how these are interlinked and have a major influence on ecology and biogeochemistry in the seafloor. Extraordinary discoveries have increased our knowledge on microbial sulfur cycling, mainly in sulfate-rich surface sediments, yet many questions remain regarding how sulfur redox processes may sustain the deep-subsurface biosphere and the impact of organic sulfur compounds on the marine sulfur cycle. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Volatile organic compound measurements in the California/Mexico border region during SCOS97

International Nuclear Information System (INIS)

Zielinska, B.; Sagebiel, J.; Harshfield, G.; Pasek, R.

2001-01-01

Measurements of volatile organic compounds (VOC) were carried out in the California/Mexico border region during the Southern California Ozone Study in the summer of 1997 (SCOS97). Integrated 3-h samples were collected in Rosarito (south of Tijuana, Mexico) and in Mexicali during intensive operational periods (IOP), twice per IOP day. VOC were collected using stainless-steel 6-l canisters; carbonyl compounds were collected using 2,4-dinitrophenylhydrazine (DNPH) impregnated C18 SepPak cartridges. The canister samples were analyzed for speciated volatile hydrocarbons (C 2 -C 12 ), CO, CO 2 , CH 4 , methyl t-butyl ether (MTBE), and halogenated hydrocarbons. DNPH-impregnated cartridges were analyzed for 14 C 1 -C 7 carbonyl compounds. The concentrations of all species were higher at Mexicali than in Rosarito. A good correlation between total non-methane hydrocarbons (TNMHC), CO, and other pollutants associated with motor vehicle emissions observed for Mexicali indicates that the main source of TNMHC at this site is vehicular traffic

Volatile compounds of young wines from cabernet sauvignon, cabernet gernischet and chardonnay varieties grown in the loess plateau region of china.

Science.gov (United States)

Jiang, Bao; Zhang, Zhenwen

2010-12-10

In order to elucidate the aroma components of wine produced in the Loess Plateau region of China, volatile compounds of young wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay varieties grown in the new ecological region were investigated for the first time in this research. Among the volatile compounds analyzed by HS-SPME with GC-MS, a total of 45, 44 and 42 volatile compounds were identified and quantified in Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. In the volatiles detected, alcohols formed the most abundant group in the aroma compounds of the three wines, followed by esters and fatty acids. According to their odor active values (OAVs), 18 volatile compounds were always present in the three wines at concentrations higher than their threshold values, but ethyl octanoate, ethyl hexanoate, and isoamyl acetate were found to jointly contribute to 92.9%, 93.3%, and 98.7%, of the global aroma of Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. These odorants are associated with "fruity'' and ''ripe fruit'' odor descriptors.

Volatile Compounds of Young Wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay Varieties Grown in the Loess Plateau Region of China

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Zhenwen Zhang

2010-12-01

Full Text Available In order to elucidate the aroma components of wine produced in the Loess Plateau region of China, volatile compounds of young wines from Cabernet Sauvignon, Cabernet Gernischet and Chardonnay varieties grown in the new ecological region were investigated for the first time in this research. Among the volatile compounds analyzed by HS-SPME with GC-MS, a total of 45, 44 and 42 volatile compounds were identified and quantified in Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. In the volatiles detected, alcohols formed the most abundant group in the aroma compounds of the three wines, followed by esters and fatty acids. According to their odor active values (OAVs, 18 volatile compounds were always present in the three wines at concentrations higher than their threshold values, but ethyl octanoate, ethyl hexanoate, and isoamyl acetate were found to jointly contribute to 92.9%, 93.3%, and 98.7%, of the global aroma of Cabernet Sauvignon, Cabernet Gernischet and Chardonnay wines, respectively. These odorants are associated with “fruity’’ and ‘‘ripe fruit’’ odor descriptors.

Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

Science.gov (United States)

Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one of the important interactions between anthropogenic emissions related to combustion and natural emissions from the biosphere. This interaction has been recognized for more than 3 d...

Assessment of volatile compound profiles and the deduced sensory significance of virgin olive oils from the progeny of Picual×Arbequina cultivars.

Science.gov (United States)

Pérez, Ana G; de la Rosa, Raúl; Pascual, Mar; Sánchez-Ortiz, Araceli; Romero-Segura, Carmen; León, Lorenzo; Sanz, Carlos

2016-01-08

Volatile compounds are responsible for most of the sensory qualities of virgin olive oil and they are synthesized when enzymes and substrates come together as olive fruit is crushed during the industrial process to obtain the oil. Here we have studied the variability among the major volatile compounds in virgin olive oil prepared from the progeny of a cross of Picual and Arbequina olive cultivars (Olea europaea L.). The volatile compounds were isolated by SPME, and analyzed by HRGC-MS and HRGC-FID. Most of the volatile compounds found in the progeny's oil are produced by the enzymes in the so-called lipoxygenase pathway, and they may be clustered into different groups according to their chain length and polyunsaturated fatty acid origin (linoleic and linolenic acids). In addition, a group of compounds derived from amino acid metabolism and two terpenes also contributed significantly to the volatile fraction, some of which had significant odor values in most of the genotypes evaluated. The volatile compound content of the progeny was very varied, widely transgressing the progenitor levels, suggesting that in breeding programs it might be more effective to consider a larger number of individuals within the same cross than using different crosses with fewer individuals. Multivariate analysis allowed genotypes with particularly interesting volatile compositions to be identified and their flavor quality deduced. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of volatile organic compounds in pleural effusions by headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry.

Science.gov (United States)

Huang, Zhongping; Zhang, Jie; Zhang, Peipei; Wang, Hong; Pan, Zaifa; Wang, Lili

2016-07-01

Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap device, with the construction of a cold column head by freezing a segment of metal capillary with liquid nitrogen. A total of 76 volatile organic compounds were identified in 50 pleural effusion samples (20 malignant effusions and 30 benign effusions). Among them, 34 more volatile organic compounds were detected with the retention time less than 8 min, by comparing with the normal headspace solid-phase microextraction coupled with gas chromatography and mass spectrometry method. Furthermore, 24 volatile organic compounds with high occurrence frequency in pleural effusion samples, 18 of which with the retention time less than 8 min, were selected for the comparative analysis. The results of average peak area comparison and box-plot analysis showed that except for cyclohexanone, 2-ethyl-1-hexanol, and tetramethylbenzene, which have been reported as potential cancer biomarkers, cyclohexanol, dichloromethane, ethyl acetate, n-heptane, ethylbenzene, and xylene also had differential expression between malignant and benign effusions. Therefore, the proposed approach was valuable for the comprehensive characterization of volatile organic compounds in pleural effusions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Volatile compound changes during shelf life of dried Boletus edulis: comparison between SPME-GC-MS and PTR-ToF-MS analysis.

Science.gov (United States)

Aprea, Eugenio; Romano, Andrea; Betta, Emanuela; Biasioli, Franco; Cappellin, Luca; Fanti, Marco; Gasperi, Flavia

2015-01-01

Drying process is commonly used to allow long time storage of valuable porcini mushrooms (Boletus edulis). Although considered a stable product dried porcini flavour changes during storage. Monitoring of volatile compounds during shelf life may help to understand the nature of the observed changes. In the present work two mass spectrometric techniques were used to monitor the evolution of volatile compounds during commercial shelf life of dried porcini. Solid phase microextraction (SPME) coupled to gas chromatography - mass spectrometry (GC-MS) allowed the identification of 66 volatile compounds, 36 of which reported for the first time, monitored during the commercial shelf life of dried porcini. Proton transfer reaction - time of flight - mass spectrometry (PTR-ToF-MS) , a direct injection mass spectrometric technique, was shown to be a fast and sensitive instrument for the general monitoring of volatile compound evolution during storage of dried porcini. Furthermore, PTR-ToF-MS grants access to compounds whose determination would otherwise require lengthy pre-concentration and/or derivatization steps such as ammonia and small volatile amines. The two techniques, both used for the first time to study dried porcini, provided detailed description of time evolution of volatile compounds during shelf life. Alcohols, aldehydes, ketones and monoterpenes diminish during the storage while carboxylic acids, pyrazines, lactones and amines increase. The storage temperature modifies the rate of the observed changes influencing the final quality of the dried porcini. We showed the advantages of both techniques, suggesting a strategy to be adopted to follow time evolution of volatile compounds in food products during shelf life, based on the identification of compounds by GC-MS and the rapid time monitoring by PTR-ToF-MS measurements in order to maximize the advantages of both techniques. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of gamma radiation on the content β-carotene and volatile compounds of cantaloupe melon

International Nuclear Information System (INIS)

Souza, Stefania P. de; Cardozo, Monique; Lima, Keila dos S.C.; Lima, Antonio L. dos S.

2011-01-01

The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs 137 source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in β-carotene. Both total content of carotenoids and specific β-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and α -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 kGy ranging from 0.8 to 9

Effect of gamma radiation on the content {beta}-carotene and volatile compounds of cantaloupe melon

Energy Technology Data Exchange (ETDEWEB)

Souza, Stefania P. de; Cardozo, Monique; Lima, Keila dos S.C.; Lima, Antonio L. dos S., E-mail: keila@ime.eb.br, E-mail: santoslima@ime.eb.br [Departamento de Quimica - IME - Instituto Militar de Engenharia, RJ (Brazil)

2011-07-01

The Japanese melon or cantaloupe (Cucumis melo L.) is characterized by fruits with almost 1.0 Kg, pulp usually salmon and musky scent. The fruits when ripe are sensitive to post harvest handling. This low transport resistance and reduced shelf-life makes it necessary to delay the ripening of fruit. In this way the use of irradiation technique is a good choice. Irradiation is the process of exposing food to high doses of gamma rays. The processing of fruits and vegetables with ionizing radiation has as main purpose to ensure its preservation. However, like other forms of food processing, irradiation may cause changes in chemical composition and nutritional value. This study aims to assess possible changes in carotene content and volatile compounds caused by exposure of cantaloupe melon fruit to gamma irradiation. Irradiation of the samples occurred in Centro Tecnologico do Exercito (Guaratiba-RJ), using Gamma irradiator (Cs{sub 137} source, dose rate 1.8 kGy/h), being applied 0.5 and 1.0 kGy doses and separated a control group not irradiated. Carotenoids were extracted with acetone and then suffered partition to petroleum ether, solvent was removed under nitrogen flow and the remainder dissolved in acetone again. The chromatographic analysis was performed using a Shimadzu gas chromatograph, with C30 column. For volatile compounds, we used gas chromatography (GC) associated with mass (MS). As a result, it was verified in analysis of carotenoids that cantaloupe melon is rich in {beta}-carotene. Both total content of carotenoids and specific {beta}-carotene amount wasn't suffer significant reduction in irradiated fruits at two doses, demonstrating that the irradiation process under these conditions implies a small loss of nutrients. The major volatile compounds were: 2-methyl-1-butyl acetate, ethyl hexanoate, n-hexyl acetate, benzyl acetate, 6-nonenyl acetate and {alpha} -terpinyl acetate. For all compounds we observed an increase in the volatile content in 0.5 k

Sulfur and nitrogen compounds in air and precipitation over the former Soviet Union in 1980-1995

Energy Technology Data Exchange (ETDEWEB)

Paramonov, S.; Ryaboshapko, A.; Gromov, S. [Inst. of Global Climate and Ecology, Moscow (Russian Federation); Granat, L.; Rodhe, H. [Stockholm Univ. (Sweden). Dept. of Meteorology

1999-12-01

Published information on sulfur and nitrogen compounds in air and precipitation in background regions of the Former Soviet Union (F SU) was collected and analyzed. Bad or doubtful data were removed. The spatial patterns of sulphur and nitrogen compounds indicate that western and southern regions are the most polluted and eastern Siberia the cleanest. Dry deposition of oxidized sulfur and nitrogen on all the F SU territory was estimated to 3.3 Mt S and 1.6 Mt N per year (an average of 0. 15 gS/m{sup 2} yr and 0.07 gN/m{sup 2} yr). Deposition with precipitation was estimated to 14.7 Mt S and 7.9 Mt N per year (an average of 0.66 gS/m{sup 2}yr and 0.35 gN/m{sup 2}yr). Deposition fluxes are largest during the warm season. Data from the GAW monitoring network during the period 1980-1995 showed a visible increase of nitrate and ammonium in precipitation whereas the concentration of sulfate was rather stable. The sulfur dioxide concentration in air decreased significantly in several regions of the F SU during the decade 1980-1990. The data on nitrogen compounds in air are too limited to permit any firm conclusions regarding trends.

Wine phenolic compounds influence the production of volatile phenols by wine-related lactic acid bacteria.

Science.gov (United States)

Silva, I; Campos, F M; Hogg, T; Couto, J A

2011-08-01

To evaluate the effect of wine phenolic compounds on the production of volatile phenols (4-vinylphenol [4VP] and 4-ethylphenol [4EP]) from the metabolism of p-coumaric acid by lactic acid bacteria (LAB). Lactobacillus plantarum, Lactobacillus collinoides and Pediococcus pentosaceus were grown in MRS medium supplemented with p-coumaric acid, in the presence of different phenolic compounds: nonflavonoids (hydroxycinnamic and benzoic acids) and flavonoids (flavonols and flavanols). The inducibility of the enzymes involved in the p-coumaric acid metabolism was studied in resting cells. The hydroxycinnamic acids tested stimulated the capacity of LAB to synthesize volatile phenols. Growth in the presence of hydroxycinnamic acids, especially caffeic acid, induced the production of 4VP by resting cells. The hydroxybenzoic acids did not significantly affect the behaviour of the studied strains. Some of the flavonoids showed an effect on the production of volatile phenols, although strongly dependent on the bacterial species. Relatively high concentrations (1 g l(-1) ) of tannins inhibited the synthesis of 4VP by Lact. plantarum. Hydroxycinnamic acids were the main compounds stimulating the production of volatile phenols by LAB. The results suggest that caffeic and ferulic acids induce the synthesis of the cinnamate decarboxylase involved in the metabolism of p-coumaric acid. On the other hand, tannins exert an inhibitory effect. This study highlights the capacity of LAB to produce volatile phenols and that this activity is markedly influenced by the phenolic composition of the medium. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Application of Atmospheric Pressure Photoionization H/D-exchange Mass Spectrometry for Speciation of Sulfur-containing Compounds.

Science.gov (United States)

Acter, Thamina; Kim, Donghwi; Ahmed, Arif; Ha, Ji-Hyoung; Kim, Sunghwan

2017-08-01

Herein we report the observation of atmospheric pressure in-source hydrogen-deuterium exchange (HDX) of thiol group for the first time. The HDX for thiol group was optimized for positive atmospheric pressure photoionization (APPI) mass spectrometry (MS). The optimized HDX-MS was applied for 31 model compounds (thiols, thiophenes, and sulfides) to demonstrate that exchanged peaks were observed only for thiols. The optimized method has been successfully applied to the isolated fractions of sulfur-rich oil samples. The exchange of one and two thiol hydrogens with deuterium was observed in the thiol fraction; no HDX was observed in the other fractions. Thus, the results presented in this study demonstrate that the HDX-MS method using APPI ionization source can be effective for speciation of sulfur compounds. This method has the potential to be used to access corrosion problems caused by thiol-containing compounds. Graphical Abstract ᅟ.

Volatile compounds and odor preferences of ground beef added with garlic and red wine, and irradiated with charcoal pack

Science.gov (United States)

Lee, Kyung Haeng; Yun, Hyejeong; Lee, Ju Woon; Ahn, Dong Uk; Lee, Eun Joo; Jo, Cheorun

2012-08-01

Irradiation is the most efficient non-thermal technology for improving hygienic quality and extending the shelf-life of food products. One of the adverse effects of food irradiation, however, is off-flavor production, which significantly affects the sensory preferences for certain foods. In this study, garlic (5%, w/w) and red wine (1:1, w/w) were added to ground beef to increase the radiation sensitivity of pathogens and improve meat odor/flavor. Samples were irradiated at 0 or 5 kGy in the presence of charcoal pack. SPME-GC-MS analysis was performed to measure the changes in the volatile compounds and sensory characteristics of the samples. The amount of total volatile compounds produced from ground beef was greater when the sample was irradiated. When garlic and red wine were added to the ground beef, the amount of volatile compounds significantly increased, and the amount of volatile compounds increased even further after irradiation. However, when the samples were irradiated with charcoal pack, the amount of volatile compounds decreased significantly. Sensory evaluation indicated that charcoal pack significantly increased the odor preferences for both irradiated and non-irradiated ground beef added with garlic. These results indicated that addition of charcoal pack to ground beef could reduce off-odor problems induced by irradiation, and this effect was consistent even when certain additives such as garlic and red wine were added.

Influence of pulsed electric field treatments on the volatile compounds of milk in comparison with pasteurized processing.

Science.gov (United States)

Zhang, Sha; Yang, Ruijin; Zhao, Wei; Hua, Xiao; Zhang, Wenbin; Zhang, Zhong

2011-01-01

Effects of pulsed electric field (PEF) treatments on the volatile profiles of milk were studied and compared with pasteurized treatment of high temperature short time (HTST) (75 °C, 15 s). Volatile compounds were extracted by solid-phase micro-extraction (SPME) and identified by gas chromatography/mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). A total of 37 volatile compounds were determined by GC-MS, and 19 volatile compounds were considered to be major contributors to the characteristic flavor of milk samples. PEF treatment resulted in an increase in aldehydes. Milk treated with PEF at 30 kV/cm showed the highest content of pentanal, hexanal, and nonanal, while heptanal and decanal contents were lower than in pasteurized milk, but higher than in raw milk. All the methyl ketones detected in PEF milk were lower than in pasteurized milk. No significant differences in acids (acetic acid, butanoic acid, hexanoic acid, octanoic acid, and decanoic acid), lactones, and alcohols were observed between pasteurized and PEF-treated samples; however, 2(5H)-furanone was only detected in PEF-treated milk. Although GC-MS results showed that there were some volatile differences between pasteurized and PEF-treated milk, GC-O data showed no significant difference between the 2 samples.

Quantitative analysis of sulfur forms of coal and the pyrolysis behavior of sulfur compounds; Sekitanchu no io kagobutsu no keitaibetsu gan`yuryo no teiryo to sono netsubunkai kyodo

Energy Technology Data Exchange (ETDEWEB)

Mae, K.; Miura, K.; Shimada, M. [Kyoto University, Kyoto (Japan). Faculty of Engineering

1996-10-28

As part of the studies on coal utilization basics, considerations were given on quantification of sulfur forms of coal and the pyrolysis behavior of sulfur compounds. With the temperature raising oxidation method, a thermo-balance was connected directly to a mass analyzer, and the coal temperature was raised at a rate of 5{degree}C per minute and gasified. Peak division was performed on SO2 and COS production to derive sulfur forms of coal. Using the slow-speed pyrolysis method, production rates of H2S, COS, SO2 and mercaptans were measured at a temperature raising rate of 20{degree}C per minute. Sulfur content in char was also measured. With the quick pyrolysis method, a Curie point pyrolyzer was connected directly to a gas chromatograph, by which secondary reaction is suppressed, and initial pyrolytic behavior can be tracked. All kinds of coals produce a considerable amount of SO2 in the slow-speed pyrolysis, but very little in the quick pyrolysis. Instead, H2S and mercaptans are produced. Sulfur compound producing mechanisms vary depending on the temperature raising rates. By using a parallel primary reaction model, analysis was made on reactions of H2S production based on different activation energies, such as those generated from pyrite decomposition and organic sulfur decomposition. The analytic result agreed also with that from the temperature raising oxidation method. 4 refs., 6 figs., 1 tab.

Impact of elevated CO2 and O3 concentrations on biogenic volatile organic compounds emissions from Ginkgo biloba.

Science.gov (United States)

Li, Dewen; Chen, Ying; Shi, Yi; He, Xingyuan; Chen, Xin

2009-04-01

In natural environment with ambient air, ginkgo trees emitted volatile organic compounds 0.18 microg g(-1) h(-1) in July, and 0.92 microg g(-1) h(-1) in September. Isoprene and limonene were the most abundant detected compounds. In September, alpha-pinene accounted for 22.5% of the total. Elevated CO(2) concentration in OTCs increased isoprene emission significantly in July (pemission was enhanced in July and decreased in September by elevated CO(2). Exposed to elevated O(3) increased the isoprene and monoterpenes emissions in July and September, and the total volatile organic compounds emission rates were 0.48 microg g(-1) h(-1) (in July) and 2.24 microg g(-1) h(-1) (in September), respectively. The combination of elevated CO(2) and O(3) did not have any effect on biogenic volatile organic compounds emissions, except increases of isoprene and Delta3-carene in September.

Measurement of in-vehicle volatile organic compounds under static conditions.

Science.gov (United States)

You, Ke-wei; Ge, Yun-shan; Hu, Bin; Ning, Zhan-wu; Zhao, Shou-tang; Zhang, Yan-ni; Xie, Peng

2007-01-01

The types and quantities of volatile organic compounds (VOCs) inside vehicles have been determined in one new vehicle and two old vehicles under static conditions using the Thermodesorber-Gas Chromatograph/Mass Spectrometer (TD-GC/MS). Air sampling and analysis was conducted under the requirement of USEPA Method TO-17. A room-size, environment test chamber was utilized to provide stable and accurate control of the required environmental conditions (temperature, humidity, horizontal and vertical airflow velocity, and background VOCs concentration). Static vehicle testing demonstrated that although the amount of total volatile organic compounds (TVOC) detected within each vehicle was relatively distinct (4940 microg/m3 in the new vehicle A, 1240 microg/m3 in used vehicle B, and 132 microg/m3 in used vehicle C), toluene, xylene, some aromatic compounds, and various C7-C12 alkanes were among the predominant VOC species in all three vehicles tested. In addition, tetramethyl succinonitrile, possibly derived from foam cushions was detected in vehicle B. The types and quantities of VOCs varied considerably according to various kinds of factors, such as, vehicle age, vehicle model, temperature, air exchange rate, and environment airflow velocity. For example, if the airflow velocity increases from 0.1 m/s to 0.7 m/s, the vehicle's air exchange rate increases from 0.15 h(-1) to 0.67 h(-1), and in-vehicle TVOC concentration decreases from 1780 to 1201 microg/m3.

Development of sampling method and chromatographic analysis of volatile organic compounds emitted from human skin.

Science.gov (United States)

Grabowska-Polanowska, Beata; Miarka, Przemysław; Skowron, Monika; Sułowicz, Joanna; Wojtyna, Katarzyna; Moskal, Karolina; Śliwka, Ireneusz

2017-10-01

The studies on volatile organic compounds emitted from skin are an interest for chemists, biologists and physicians due to their role in development of different scientific areas, including medical diagnostics, forensic medicine and the perfume design. This paper presents a proposal of two sampling methods applied to skin odor collection: the first one uses a bag of cellulose film, the second one, using cellulose sachets filled with active carbon. Volatile organic compounds were adsorbed on carbon sorbent, removed via thermal desorption and analyzed using gas chromatograph with mass spectrometer. The first sampling method allowed identification of more compounds (52) comparing to the second one (30). Quantitative analyses for acetone, butanal, pentanal and hexanal were done. The skin odor sampling method using a bag of cellulose film, allowed the identification of many more compounds when compared with the method using a sachet filled with active carbon.

Characterization of odor-active compounds in cooked meat of farmed obscure puffer (Takifugu obscurus using gas chromatography–mass spectrometry–olfactometry

Directory of Open Access Journals (Sweden)

Ning-Ping Tao

2014-12-01

Full Text Available The volatile and odor-active compounds in cooked meat of farmed obscure puffer (Takifugu obscurus were analyzed by gas chromatography–mass spectrometry–olfactometry (GC–MS–O. The volatile compounds were extracted by the simultaneous distillation–extraction (SDE method, then separated and identified by GC–MS. Odor-active compounds in the SDE extract were characterized by GC–MS–O. A total of 68 volatile compounds were found, including 23 aldehydes, 10 alcohols, nine ketones, 17 N- or S-containing compounds and aromatics, three acids, three alkanes, and three esters. Of these, 31 odor-active compounds were detected and identified. Trimethylamine (fishy, octanal (grassy, leafy, green, (E-2-octenal (roast, fatty, 1-octen-3-ol (fishy, fatty, mushroom, grassy, 2-ethyl-1-hexanethiol (cooked fish, (E,E-2,4-octadienal (cooked meat, sweet, 2-acetylthiazole (meaty, roast, nutty, sulfur, 2-acetylpyrrole (nutty, walnut, bread were identified as the key odorants in the cooked meat of farmed obscure puffer based on posterior intensity and time-intensity methods.

Volatile organic compound (VOC) emissions during malting and beer manufacture

Science.gov (United States)

Gibson, Nigel B.; Costigan, Gavin T.; Swannell, Richard P. J.; Woodfield, Michael J.

Estimates have been made of the amounts of volatile organic compounds (VOCs) released during different stages of beer manufacture. The estimates are based on recent measurements and plant specification data supplied by manufacturers. Data were obtained for three main manufacturing processes (malting, wort processing and fermentation) for three commercial beer types. Some data on the speciation of emitted compounds have been obtained. Based on these measurements, an estimate of the total unabated VOC emission. from the U.K. brewing industry was calculated as 3.5 kta -1, over 95% of which was generated during barley malting. This value does not include any correction for air pollution control.

Application of HS-SPME and GC-MS to characterization of volatile compounds emitted from Osmanthus flowers.

Science.gov (United States)

Deng, Chunhui; Song, Guoxin; Hu, Yaoming

2004-12-01

Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for characterization of volatile compounds emitted from two varieties Osmanthus flowers of O. fragrans var. latifolius and O. fragrans var. thunbergii. The SPME parameters were studied, the optimum conditions of a 65 microm carbowax/divinylbenzene (CW/DVB), extraction temperature of 22 degrees C and extraction time of 10 min were obtained and applied to extraction of the volatile emissions. Fourteen compounds released from both varieties of Osmanthus flowers were separated and identified by GC-MS, which mainly included alpha-linalool, beta-linalool, trans-linalool oxide, cis-linalool oxide, alpha-lonone, beta-lonone, capraldehyde and decalactone. By comparing their peak areas, we found that the sums of the fourteen compounds from the two Osmanthus flowers were very close, while the relative contents of individual volatile compounds in the two emissions were very different. The relative content of alpha-linalool and beta-linalool in O. fragrans var. latifolius were 39.46% and 0.51%, while in O. fragrans var. thunbergii were 9.53% and 27.71%. Due to their different relative contents, the two varieties of flower have different fragrances.

Characterisation of commercial aromatised vinegars: phenolic compounds, volatile composition and antioxidant activity.

Science.gov (United States)

Cejudo-Bastante, María J; Durán-Guerrero, Enrique; Natera-Marín, Ramón; Castro-Mejías, Remedios; García-Barroso, Carmelo

2013-04-01

Nineteen commercially available aromatised vinegars, which were representative of this type of product, were tested to ascertain their phenolic and volatile composition and antioxidant activity. The aromatised vinegars came from different raw materials such as fruits, spices, herbs and vegetables. The antioxidant activity was determined by means of photochemiluminescence, phenolic profile by using ultra performance liquid chromatography with ultraviolet detection, and the volatile composition was determined by using stir bar sorptive extraction-gas chromatography-mass spectrometry. Nine polyphenolic compounds and 141 volatile compounds were identified. Vinegar aromatised with black truffle and rosemary obtained the highest values of antioxidant activity, followed by those aromatised with lemon, tarragon, aromatic herbs and vegetables. Antioxidant activity was highly correlated with the presence of trans-p-coutaric acid, trans-caftaric acid, 5-hydroxy-methylfurfural and furfural. Moreover, (Z)-3-hexen-1-ol was exclusive to the vinegar aromatised with tarragon, while p-menth-1,8-ol, dimethyl styrene, 4-methyl acetophenone and nootkatone were only found in vinegar aromatised with lemon. On the basis of the results from the cluster analysis of cases, it can be concluded that the grouping responds more to the trademark of each vinegar than to the raw material. © 2012 Society of Chemical Industry.

Volatile compounds and odor preferences of ground beef added with garlic and red wine, and irradiated with charcoal pack

International Nuclear Information System (INIS)

Lee, Kyung Haeng; Yun, Hyejeong; Lee, Ju Woon; Ahn, Dong Uk; Lee, Eun Joo; Jo, Cheorun

2012-01-01

Irradiation is the most efficient non-thermal technology for improving hygienic quality and extending the shelf-life of food products. One of the adverse effects of food irradiation, however, is off-flavor production, which significantly affects the sensory preferences for certain foods. In this study, garlic (5%, w/w) and red wine (1:1, w/w) were added to ground beef to increase the radiation sensitivity of pathogens and improve meat odor/flavor. Samples were irradiated at 0 or 5 kGy in the presence of charcoal pack. SPME-GC–MS analysis was performed to measure the changes in the volatile compounds and sensory characteristics of the samples. The amount of total volatile compounds produced from ground beef was greater when the sample was irradiated. When garlic and red wine were added to the ground beef, the amount of volatile compounds significantly increased, and the amount of volatile compounds increased even further after irradiation. However, when the samples were irradiated with charcoal pack, the amount of volatile compounds decreased significantly. Sensory evaluation indicated that charcoal pack significantly increased the odor preferences for both irradiated and non-irradiated ground beef added with garlic. These results indicated that addition of charcoal pack to ground beef could reduce off-odor problems induced by irradiation, and this effect was consistent even when certain additives such as garlic and red wine were added. - Highlights: ► Garlic and red wine were added to ground beef and irradiated at 5 kGy in the presence of charcoal pack. ► When the samples were irradiated with charcoal pack, the amount of volatile compounds decreased significantly and it affected sensory score. ► Thus, addition of charcoal pack to ground beef could reduce off-odor problems induced by irradiation. ► This effect was consistent when additives, such as garlic and red wine, were added into ground beef.

Contribution of Histidine and Lysine to the Generation of Volatile Compounds in Jinhua Ham Exposed to Ripening Conditions Via Maillard Reaction.

Science.gov (United States)

Zhu, Chao-Zhi; Zhao, Jing-Li; Tian, Wei; Liu, Yan-Xia; Li, Miao-Yun; Zhao, Gai-Ming

2018-01-01

To evaluate the role of Maillard reactions in the generation of flavor compounds in Jinhua ham, the reactions of glucose and ethanal with histidine and lysine, respectively, were studied by simulating the ripening conditions of Jinhua ham. The volatile products produced were analyzed using solid phase microextraction-gas chromatography/mass spectrometry. The results showed that 8 volatile compounds were generated by the reaction of glucose and histidine and 10 volatile compounds were generated by the reaction of glucose and lysine. Reactions of ethanal with lysine and with histidine both generated 31 volatile compounds that contributed to the flavor of Jinhua ham. This indicates that histidine and lysine related to Maillard reactions possibly play important roles in the generation of the unique flavor compounds in Jinhua ham. This research demonstrates that free amino acids participate in the generation of volatile compounds from Jinhua ham via the Maillard reaction and provides a basic mechanism to explain flavor formation in Jinhua ham. Jinhua ham is a well-known traditional Chinese dry-cured meat product. However, the formation of the compounds comprising its special flavor is not well understood. Our results indicate that Maillard reactions occur in Jinhua ham under ripening conditions. This work illustrates the contribution of Maillard reactions to the flavor of Jinhua ham. © 2017 Institute of Food Technologists®.

Simultaneous Microwave Extraction and Separation of Volatile and Non-Volatile Organic Compounds of Boldo Leaves. From Lab to Industrial Scale

Directory of Open Access Journals (Sweden)

Loïc Petigny

2014-04-01

Full Text Available Microwave extraction and separation has been used to increase the concentration of the extract compared to the conventional method with the same solid/liquid ratio, reducing extraction time and separate at the same time Volatile Organic Compounds (VOC from non-Volatile Organic Compounds (NVOC of boldo leaves. As preliminary study, a response surface method has been used to optimize the extraction of soluble material and the separation of VOC from the plant in laboratory scale. The results from the statistical analysis revealed that the optimized conditions were: microwave power 200 W, extraction time 56 min and solid liquid ratio of 7.5% of plants in water. Lab scale optimized microwave method is compared to conventional distillation, and requires a power/mass ratio of 0.4 W/g of water engaged. This power/mass ratio is kept in order to upscale from lab to pilot plant.

Actinobacillus pleuropneumoniae is impaired by the garlic volatile allyl methyl sulfide (AMS) in vitro and in-feed garlic alleviates pleuropneumonia in a pig model

NARCIS (Netherlands)

Becker, P.M.; Wikselaar, van P.G.; Mul, M.F.; Pol, A.; Engel, B.; Wijdenes, J.W.; Peet-Schwering, van der C.M.C.; Wisseling, H.J.; Stockhofe-Zurwieden, N.

2012-01-01

Decomposition products of ingested garlic are to a certain extent excreted via the lungs. If the supposed health-supporting capacities associated with garlic extend to these exhaled sulfurous compounds, they could have an effect on the course of pneumonia. In this study, the garlic-derived volatile

Transformation of sulfur during pyrolysis and hydropyrolysis of coal

Energy Technology Data Exchange (ETDEWEB)

Chen, H.; Li, B.; Yang, J.; Zhang, B. [Chinese Academy of Sciences, Taiyuan (China). Inst. of Coal Chemistry

1998-05-01

It is reported that the transformation of sulfur during pyrolysis (Py) under nitrogen and hydropyrolysis (HyPy) of Chinese Yanzhou high sulfur bituminous coal and Hongmiao lignite was studied in a fixed-bed reactor. The volatile sulfur-containing products were determined by gas chromatography with flame photometric detection. The sulfur in initial coal and char (mainly aliphatic and thiophenic sulfur forms) was quantitatively analyzed using X-ray photoelectron spectroscopy (XPS). The desulfurization yield was calculated by elemental analysis. The main volatile sulfur-containing gas was H{sub 2}S in both Py and HyPy. Both the elemental analysis and XPS results indicated that more sulfur was removed in HyPy than in Py under nitrogen. Thiophenic sulfur can be partially hydrogenated and removed in HyPy. Pyrite can be reduced to a ferrous sulfide completely even as low as 400{degree}C in HyPy while in Py the reduction reaction continues up to 650{degree}C. Mineral matter can not only fix H{sub 2}S produced in Py and HyPy to form higher sulfur content chars but also catalyses the desulfurization reactions to form lower sulfur content tars in HyPy. 24 refs., 8 figs., 4 tabs.

Volatile Compounds and Inositol Hexakisphosphate (IP6) Content in Wholemeal Wheat Bread

DEFF Research Database (Denmark)

Mohd Noor, Nor Qhairul Izzreen B

. The volatile compounds were extracted with dynamic headspace extraction and analyzed with gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In paper I, the crumb fermented at high temperature (32°C) had higher relative areas of the Maillard reaction...

A method for eliminating sulfur compounds from fluid, saturated, aliphatic hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Fakhriev, A.M.; Galiautdinov, N.G.; Kashevarov, L.A.; Mazgarov, A.M.

1982-01-01

The method for eliminating sulfur compounds from fluid, saturated, aliphatic hydrocarbons, which involves extracting hydrocarbons using a dimethylsulfoxide extractant, is improved by using a dimethylsulfoxide blend and 10-60 percent (by volume) diethylenetriamine or polyethylenepolyamine which contains diethylenetriamine, triethylenetetramine and tetraethylenepentamine, in order to eliminate the above compounds. Polyethylenepolyamine is produced as a by-product during the production of ethylenediamine. Elimination is performed at 0-50 degrees and 1-60 atmospheres of pressure. Here, the extractant may contain up to 10 percent water. The use of the proposed method, rather than the existing method, will make it possible to increase hydrocarbon elimination from mercaptans by 40 percent and from H/sub 2/S by 10 percent when the same amount is eliminated from dialkylsulfides.

Tissue-Specific Accumulation of Sulfur Compounds and Saponins in Different Parts of Garlic Cloves from Purple and White Ecotypes.

Science.gov (United States)

Diretto, Gianfranco; Rubio-Moraga, Angela; Argandoña, Javier; Castillo, Purificación; Gómez-Gómez, Lourdes; Ahrazem, Oussama

2017-08-20

This study set out to determine the distribution of sulfur compounds and saponin metabolites in different parts of garlic cloves. Three fractions from purple and white garlic ecotypes were obtained: the tunic (SS), internal (IS) and external (ES) parts of the clove. Liquid Chromatography coupled to High Resolution Mass spectrometry (LC-HRMS), together with bioinformatics including Principal Component Analysis (PCA), Hierarchical Clustering (HCL) and correlation network analyses were carried out. Results showed that the distribution of these metabolites in the different parts of garlic bulbs was different for the purple and the white ecotypes, with the main difference being a slightly higher number of sulfur compounds in purple garlic. The SS fraction in purple garlic had a higher content of sulfur metabolites, while the ES in white garlic was more enriched by these compounds. The correlation network indicated that diallyl disulfide was the most relevant metabolite with regards to sulfur compound metabolism in garlic. The total number of saponins was almost 40-fold higher in purple garlic than in the white variety, with ES having the highest content. Interestingly, five saponins including desgalactotigonin-rhamnose, proto-desgalactotigonin, proto-desgalactotigonin-rhamnose, voghieroside D1, sativoside B1-rhamnose and sativoside R1 were exclusive to the purple variety. Data obtained from saponin analyses revealed a very different network between white and purple garlic, thus suggesting a very robust and tight coregulation of saponin metabolism in garlic. Findings in this study point to the possibility of using tunics from purple garlic in the food and medical industries, since it contains many functional compounds which can be exploited as ingredients.

Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques.

Science.gov (United States)

Tres, A; Ruiz-Samblas, C; van der Veer, G; van Ruth, S M

2013-04-15

Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been applied to verify the geographical origin of crude palm oil (continental scale). For this purpose 94 crude palm oil samples were collected from South East Asia (55), South America (11) and Africa (28). Partial least squares discriminant analysis (PLS-DA) was used to develop a hierarchical classification model by combining two consecutive binary PLS-DA models. First, a PLS-DA model was built to distinguish South East Asian from non-South East Asian palm oil samples. Then a second model was developed, only for the non-Asian samples, to discriminate African from South American crude palm oil. Models were externally validated by using them to predict the identity of new authentic samples. The fatty acid fingerprinting model revealed three misclassified samples. The volatile compound fingerprinting models showed an 88%, 100% and 100% accuracy for the South East Asian, African and American class, respectively. The verification of the geographical origin of crude palm oil is feasible by fatty acid and volatile compound fingerprinting. Further research is required to further validate the approach and to increase its spatial specificity to country/province scale. Copyright © 2012 Elsevier Ltd. All rights reserved.

Combined removal of sulfur compounds and nitrate by autotrophic denitrication in bioaugmented activated sludge system

NARCIS (Netherlands)

Manconi, I.; Carucci, A.; Lens, P.N.L.

2007-01-01

An autotrophic denitrification process using reduced sulfur compounds (thiosulfate and sulfide) as electron donor in an activated sludge system is proposed as an efficient and cost effective alternative to conventional heterotrophic denitrification for inorganic (or with low C/N ratio) wastewaters

Comparison of SPME Methods for Determining Volatile Compounds in Milk, Cheese, and Whey Powder

Directory of Open Access Journals (Sweden)

Michael H. Tunick

2013-11-01

Full Text Available Solid phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS are commonly used for qualitative and quantitative analysis of volatile compounds in various dairy products, but conditions have to be adjusted to maximize release while not generating new compounds that are absent in the original sample. Queso Fresco, a fresh non-melting cheese, may be heated at 60 °C for 30 min; in contrast, compounds are produced in milk when exposed to light and elevated temperatures, so milk samples are heated as little as possible. Products such as dehydrated whey protein are more stable and can be exposed to longer periods (60 min of warming at lower temperature (40 °C without decomposition, allowing for capture and analysis of many minor components. The techniques for determining the volatiles in dairy products by SPME and GC-MS have to be optimized to produce reliable results with minimal modifications and analysis times.

Lipid and cholesterol oxidation, color changes, and volatile compounds production in irradiated raw pork batters with different fat content

International Nuclear Information System (INIS)

Jo, Cheo Run; Byun, Myung Woo

2000-01-01

An emulsion-type product was prepared to determine the effect of irradiation on lipid and cholesterol oxidation, color change, and volatile production in raw pork with different fat content. Lipid oxidation increased with an increase in fat content or irradiation dose. Irradiated batters had higher cholesterol oxides than did non-irradiated batters, and the major cholesterol oxides formed in irradiated pork batters were 7α- and 7β- hydroxycholesterol. Hunter color a- and b-values of raw pork batters were decreased by irradiation regardless of fat content. Irradiation significantly increased the amount of volatile compounds. Although lipid oxidation of high fat products (10 and 15% fat) was higher than that of low fat products (4%), high fat products did not always produce greater amount of volatile compounds in raw pork batters. In summary, irradiation increased lipid and cholesterol oxidation, and volatile compounds production, and had detrimental effects on the color of raw pork batter under aerobic conditions

Measurement and estimated health risks of volatile organic compounds and polychlorinated biphenyls in air at the Hanford Site

International Nuclear Information System (INIS)

Patton, G.W.; Cooper, A.T.; Blanton, M.L.

1994-10-01

A variety of radioactive and nonradioactive chemicals have been released in effluent streams and discharged to waste disposal facilities during the nuclear materials production period at the Hanford Site. Extensive environmental surveillance for radioactive materials has occurred at Hanford; however, only limited information is available on the types and concentrations of organic pollutants potentially present. This report describes work performed to provide the Hanford Site Surface Environmental Surveillance Project with representative air concentration data for volatile organic compounds and polychlorinated biphenyls (PCBs). US Environmental Protection Agency (USEPA) volatile organic compound sampling methods evaluated for Hanford Site use were carbon-based adsorbent traps (TO-2) and Summa air canisters (TO-14). Polychlorinated biphenyls were sampled using USEPA method (TO-4), which uses glass fiber filters and polyurethane foam adsorbent beds to collect the PCBS. This report also presents results for environmental surveillance samples collected for volatile organic compound and PCB analyses from 1990 to 1993. All measured air concentrations of volatile organic compounds and PCBs were well below applicable maximum allowable concentration standards for air contaminants. Because of the lack of ambient air concentration standards, a conservative estimate is provided of the potential human health impacts from exposure to the ambient air concentrations measured on the Hanford Site

Modelling of the Kinetics of Sulfure Compounds in Desulfurisation Processes Based on Industry Data of Plant

OpenAIRE

Krivtsova, Nadezhda Igorevna; Tataurshikov, A.; Kotkova, Elena

2016-01-01

Modelling of sulfur compounds kinetics was performed, including kinetics of benzothiophene and dibenzothiophene homologues. Modelling is based on experimental data obtained from monitoring of industrial hydrotreating set. Obtained results include kinetic parameters of reactions.

Measuring Sulfur Isotope Ratios from Solid Samples with the Sample Analysis at Mars Instrument and the Effects of Dead Time Corrections

Science.gov (United States)

Franz, H. B.; Mahaffy, P. R.; Kasprzak, W.; Lyness, E.; Raaen, E.

2011-01-01

The Sample Analysis at Mars (SAM) instrument suite comprises the largest science payload on the Mars Science Laboratory (MSL) "Curiosity" rover. SAM will perform chemical and isotopic analysis of volatile compounds from atmospheric and solid samples to address questions pertaining to habitability and geochemical processes on Mars. Sulfur is a key element of interest in this regard, as sulfur compounds have been detected on the Martian surface by both in situ and remote sensing techniques. Their chemical and isotopic composition can belp constrain environmental conditions and mechanisms at the time of formation. A previous study examined the capability of the SAM quadrupole mass spectrometer (QMS) to determine sulfur isotope ratios of SO2 gas from a statistical perspective. Here we discuss the development of a method for determining sulfur isotope ratios with the QMS by sampling SO2 generated from heating of solid sulfate samples in SAM's pyrolysis oven. This analysis, which was performed with the SAM breadboard system, also required development of a novel treatment of the QMS dead time to accommodate the characteristics of an aging detector.

Enhanced fatty acid production in engineered chemolithoautotrophic bacteria using reduced sulfur compounds as energy sources

DEFF Research Database (Denmark)

Beller, Harry R.; Zhou, Peng; Jewell, Talia N.M.

2016-01-01

Chemolithoautotrophic bacteria that oxidize reduced sulfur compounds, such as H2S, while fixing CO2 are an untapped source of renewable bioproducts from sulfide-laden waste, such as municipal wastewater. In this study, we report engineering of the chemolithoautotrophic bacterium Thiobacillus...

Identification and Quantification of Volatile Compounds Found in Vinasses from Two Different Processes of Tequila Production

Directory of Open Access Journals (Sweden)

Elizabeth Rodríguez-Félix

2018-02-01

Full Text Available Vinasses are the main byproducts of ethanol distillation and distilled beverages worldwide and are generated in substantial volumes. Tequila vinasses (TVs could be used as a feedstock for biohydrogen production through a dark fermentative (DF process due to their high content of organic matter. However, TV components have not been previously assayed in order to evaluate if they may dark ferment. This work aimed to identify and quantify volatile compounds (VC in TV and determine if the VC profile depends upon the type of production process (whether the stems were initially cooked or not. TVs were sampled from 3 agave stems with a not-cooking (NC process, and 3 agave stems with a cooking (C process, and volatile compounds were determined by gas chromatography coupled with mass spectrometry (GC–MS. A total of 111 volatile compounds were identified, the TV from the cooking process (C showed the higher presence of furanic compounds (furfural and 5-(hydroxymethyl furfural and organic acids (acetic acid and butyric acid, which have been reported as potential inhibitors for DF. To our knowledge, this is the first description of the VC composition from TVs. This study could serve as a base for further investigations related to vinasses from diverse sources.

Gaseous byproducts from high-temperature thermal conversion elemental analysis of nitrogen- and sulfur-bearing compounds with considerations for δ2H and δ18O analyses.

Science.gov (United States)

Hunsinger, Glendon B; Tipple, Christopher A; Stern, Libby A

2013-07-30

High-temperature, conversion-reduction (HTC) systems convert hydrogen and oxygen in materials into H2 and CO for δ(2)H and δ(18)O measurements by isotope ratio mass spectrometry. HTC of nitrogen- and sulfur-bearing materials produces unintended byproduct gases that could affect isotope analyses by: (1) allowing isotope exchange reactions downstream of the HTC reactor, (2) creating isobaric or co-elution interferences, and (3) causing deterioration of the chromatography. This study characterizes these HTC byproducts. A HTC system (ThermoFinnigan TC/EA) was directly connected to a gas chromatograph/quadrupole mass spectrometer in scan mode (m/z 8 to 88) to identify the volatile products generated by HTC at conversion temperatures of 1350 °C and 1450 °C for a range of nitrogen- and sulfur-bearing solids [keratin powder, horse hair, caffeine, ammonium nitrate, potassium nitrate, ammonium sulfate, urea, and three nitrated organic explosives (PETN, RDX, and TNT)]. The prominent HTC byproduct gases include carbon dioxide, hydrogen cyanide, methane, acetylene, and water for all nitrogen-bearing compounds, as well as carbon disulfide, carbonyl sulfide, and hydrogen sulfide for sulfur-bearing compounds. The 1450 °C reactor temperature reduced the abundance of most byproduct gases, but increased the significant byproduct, hydrogen cyanide. Inclusion of a post-reactor chemical trap containing Ascarite II and Sicapent, in series, eliminated the majority of byproducts. This study identified numerous gaseous HTC byproducts. The potential adverse effects of these gases on isotope ratio analyses are unknown but may be mitigated by higher HTC reactor temperatures and purifying the products with a purge-and-trap system or with chemical traps. Published in 2013. This article is a U.S. Government work and is in the public domain in the USA.

Characterization of volatile compounds produced by Lactobacillus helveticus strains in a hard cheese model.

Science.gov (United States)

Cuffia, Facundo; Bergamini, Carina V; Wolf, Irma V; Hynes, Erica R; Perotti, María C

2018-01-01

Starter cultures of Lactobacillus helveticus used in hard cooked cheeses play an important role in flavor development. In this work, we studied the capacity of three strains of L. helveticus, two autochthonous (Lh138 and Lh209) and one commercial (LhB02), to grow and to produce volatile compounds in a hard cheese extract. Bacterial counts, pH, profiles of organic acids, carbohydrates, and volatile compounds were analyzed during incubation of extracts for 14 days at 37 ℃. Lactobacilli populations were maintained at 10 6 CFU ml -1 for Lh138, while decreases of approx. 2 log orders were found for LhB02 and Lh209. Both Lh209 and LhB02 slightly increased the acetic acid content whereas mild increase in lactic acid was produced by Lh138. The patterns of volatiles were dependent on the strain which reflect their distinct enzymatic machineries: LhB02 and Lh209 produced a greater diversity of compounds, while Lh138 was the least producer strain. Extracts inoculated with LhB02 and Lh 209 were characterized by ketones, esters, alcohols, aldehydes, and acids, whereas in the extracts with Lh138 the main compounds belonged to aromatic, aldehydes, and ketones groups. Therefore, Lh209 and LhB02 could represent the best cheese starters to improve and intensify the flavor, and even a starter composed by combinations of LhB02 or Lh209 with Lh138 could also be a strategy to diversify cheese flavor.

Determinants of the Sensory Quality of Półgęsek in Relation to Volatile Compounds and Chemical Composition

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Nowicka Katarzyna

2017-12-01

Full Text Available The objective of this study was to determine the sensory quality of a specific Polish traditional product made from cured and then smoked goose meat (półgęsek in relation to its volatile compounds and chemical composition. In general, the examined samples contained 66.2% water, 12.2% fat, 17.9% protein, 1.8% connective tissue, and 2.3% NaCl. Moreover, 47 volatile compounds were identified and quantified. The typical decomposition products derived from lipid oxidation, amino acid degradation, carbohydrate fermentation and microbial esterification were the main volatiles detected in all the samples. The volatiles generated by the smoking process and the ones originating from spices were also observed. The results of the sensory evaluation indicated that all the samples of the analyzed products were characterized by a high overall quality. Results of the Principal Component Analysis (PCA showed, however, that specific groups of products have their own unique sensory profile. Additionally, the sensory analysis confirmed the significant role of the chemical composition and volatile compounds in the development of the overall quality of półgęsek.

Impact of yeast starter formulations on the production of volatile compounds during wine fermentation.

Science.gov (United States)

Romano, Patrizia; Pietrafesa, Rocchina; Romaniello, Rossana; Zambuto, Marianna; Calabretti, Antonella; Capece, Angela

2015-01-01

The most diffused starter formulation in winemaking is actually represented by active dry yeast (ADY). Spray-drying has been reported as an appropriate preservation method for yeast and other micro-organisms. Despite the numerous advantages of this method, the high air temperatures used can negatively affect cell viability and the fermentative performance of dried cells. In the present study, 11 wine S. cerevisiae strains (both indigenous and commercial) were submitted to spray-drying; different process conditions were tested in order to select the conditions allowing the highest strain survival. The strains exhibited high variability for tolerance to spray-drying treatment. Selected strains were tested in fermentation at laboratory scale in different formulations (free fresh cells, free dried cells, immobilized fresh cells and immobilized dried cells), in order to assess the influence of starter formulation on fermentative fitness of strains and aromatic quality of wine. The analysis of volatile fraction in the experimental wines produced by selected strains in different formulations allowed identification of > 50 aromatic compounds (alcohols, esters, ketones, aldehydes and terpenes). The results obtained showed that the starter formulation significantly influenced the content of volatile compounds. In particular, the wines obtained by strains in dried forms (as both free and immobilized cells) contained higher numbers of volatile compounds than wines obtained from fresh cells. Copyright © 2014 John Wiley & Sons, Ltd.

A portable and inexpensive method for quantifying ambient intermediate volatility organic compounds

Science.gov (United States)

Bouvier-Brown, Nicole C.; Carrasco, Erica; Karz, James; Chang, Kylee; Nguyen, Theodore; Ruiz, Daniel; Okonta, Vivian; Gilman, Jessica B.; Kuster, William C.; de Gouw, Joost A.

2014-09-01

Volatile organic compounds (VOCs) and intermediate volatility VOCs (IVOCs) are gas-phase organic compounds which may participate in chemical reactions affecting air quality and climate. The development of an inexpensive, field-portable quantification method for higher molecular weight VOCs and IVOCs utilizing commercially available components could be used as a tool to survey aerosol precursors or identify and monitor air quality in various communities. We characterized the performance characteristics for the HayeSep-Q adsorbent with a representative selection of anthropogenic and biogenic VOC standards and optimized experimental conditions and procedures for field collections followed by laboratory analysis. All VOCs were analyzed using gas chromatography coupled with mass spectrometry. Precision (average 22%) and accuracy were reasonable and the limit of detection ranged from 10 to 80 pmol/mol (ppt) for the studied compounds. The method was employed at the Los Angeles site during the CalNex campaign in summer 2010 and ambient mixing ratios agreed well (slope 0.69-1.06, R2 0.67-0.71) with measurements made using an in-situ GC-MS - a distinctly different sampling and quantification method. This new technique can be applied to quantify ambient biogenic and anthropogenic C8-C15 VOCs and IVOCs.

Volatile Compounds and Sensory Profiles of Monovarietal Virgin Olive Oil from Buža, Črna and Rosinjola Cultivars in Istria (Croatia

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Barbara Sladonja

2012-01-01

Full Text Available The volatile compounds found in virgin olive oil, mainly C6 and C5 volatile compounds biogenerated from polyunsaturated fatty acids through the lipoxygenase pathway, are responsible for their particular aroma. The composition of volatile compounds in olive oil depends on the cultivar, the ripening degree of the fruits and processing conditions. Among many different autochthonous cultivars in Istria (Croatia, some of the most prevalent are Buža, Črna and Rosinjola. The volatiles and sensory characteristics of their monovarietal virgin olive oil are little known. Therefore, fruits from these three cultivars were handpicked at the same ripening degree and processed under the same conditions. Quantitative descriptive sensory analysis of monovarietal virgin olive oil was carried out by the panel. Volatile composition was evaluated by headspace solid phase microextraction-gas chromatography, previously optimized and validated. The main parameters affecting effectiveness, time and temperature of extraction were optimized. The extraction procedure showed detection and quantification limits, as well as linear ranges adequate for the analysis of selected volatile compounds. Good precision was obtained both in terms of intra-day repeatability (relative standard deviations generally lower than 7 % and inter-day precision. The tested types of monovarietal olive oil showed different volatile profiles, although E-2-hexenal was the main compound in all samples. Buža oil was the richest in total C6 and C5 volatile compounds. The results show that the most important contributors to the olive oil aroma (odour activity value >1.0 were 1-penten-3-one, E-2-hexenal, hexanal, hexanol, Z-3-hexen-1-ol and Z-2-penten-1-ol. These chemical findings were compared with those provided by the panel test. Buža had the highest intensity of sensory characteristic 'other ripe fruits' and Rosinjola had the highest intensity of sensory characteristic 'bitter'. All results show

FIELD SCREENING FOR HALOGENATED VOLATILE ORGANIC COMPOUNDS

Energy Technology Data Exchange (ETDEWEB)

John F. Schabron; Joseph F. Rovani Jr.; Theresa M. Bomstad

2002-06-01

Western Research Institute (WRI) initiated exploratory work towards the development of new field screening methodology and a test kit to measure halogenated volatile organic compounds (VOCs) in the field. Heated diode and corona discharge sensors are commonly used to detect leaks of refrigerants from air conditioners, freezers, and refrigerators. They are both selective to the presence of carbon-halogen bonds. Commercially available heated diode and corona discharge leak detectors were procured and evaluated for halogenated VOC response. The units were modified to provide a digital readout of signal related to VOC concentration. Sensor response was evaluated with carbon tetrachloride and tetrachloroethylene (perchloroethylene, PCE), which represent halogenated VOCs with and without double bonds. The response characteristics were determined for the VOCs directly in headspace in Tedlar bag containers. Quantitation limits in air were estimated. Potential interferences from volatile hydrocarbons, such as toluene and heptane, were evaluated. The effect of humidity was studied also. The performance of the new devices was evaluated in the laboratory by spiking soil samples and monitoring headspace for halogenated VOCs. A draft concept of the steps for a new analytical method was outlined. The results of the first year effort show that both devices show potential utility for future analytical method development work towards the goal of developing a portable test kit for screening halogenated VOCs in the field.

Volatile compounds formation in alcoholic fermentation from grapes collected at 2 maturation stages: influence of nitrogen compounds and grape variety.

Science.gov (United States)

Martínez-Gil, Ana M; Garde-Cerdán, Teresa; Lorenzo, Cándida; Lara, José Félix; Pardo, Francisco; Salinas, M Rosario

2012-01-01

The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 wk before harvest and at harvest. Then, the musts were inoculated with the same Saccharomyces cerevisiae yeast strain and were fermented in the same winemaking conditions. Amino acids that showed the highest and the lowest concentration in the must were the same, regardless of the grape variety and maturation stage. Moreover, the consumption of amino acids during the fermentation increased with their concentration in the must. The formation of volatile compounds was not nitrogen composition dependent. However, the concentration of amino acids in the must from grapes collected 1 wk before harvest can be used as a parameter to estimate the concentration of esters in wines from grapes collected at harvest and therefore to have more information to know the grape oenological capacity. Application of principal components analysis (PCA) confirmed the possibility to estimate the concentration of esters in the wines with the concentration of nitrogen compounds in the must. © 2011 Institute of Food Technologists®

User's guide for polyethylene-based passive diffusion bag samplers to obtain volatile organic compound concentrations in wells. Part I, Deployment, recovery, data interpretation, and quality control and assurance

Science.gov (United States)

Vroblesky, Don A.

2001-01-01

Diffusion samplers installed in observation wells were found to be capable of yielding representative water samples for chlorinated volatile organic compounds. The samplers consisted of polyethylene bags containing deionized water and relied on diffusion of chlorinated volatile organic compounds through the polyethylene membrane. The known ability of polyethylene to transmit other volatile compounds, such as benzene and toluene, indicates that the samplers can be used for a variety of volatile organic compounds. In wells at the study area, the volatile organic compound concentrations in water samples obtained using the samplers without prior purging were similar to concentrations in water samples obtained from the respective wells using traditional purging and sampling approaches. The low cost associated with this approach makes it a viable option for monitoring large observation-well networks for volatile organic compounds.

Modelling of the Kinetics of Sulfure Compounds in Desulfurisation Processes Based on Industry Data of Plant

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Krivtcova Nadezhda

2016-01-01

Full Text Available Modelling of sulfur compounds kinetics was performed, including kinetics of benzothiophene and dibenzothiophene homologues. Modelling is based on experimental data obtained from monitoring of industrial hydrotreating set. Obtained results include kinetic parameters of reactions.

Determination of volatile compounds of the first rose oil and the first ...

African Journals Online (AJOL)

Background: Rose water and rose oil are used in the perfume, cosmetic, pharmaceutical and food industries. The determination of volatile compounds in rose oil and rose water obtained from oil-bearing rose is highly important in terms of availability in the industry and in human health. Materials and Methods: Twenty four ...

Volatile compounds in cryptic species of the Aneura pinguis complex and Aneura maxima (Marchantiophyta, Metzgeriidae).

Science.gov (United States)

Wawrzyniak, Rafał; Wasiak, Wiesław; Bączkiewicz, Alina; Buczkowska, Katarzyna

2014-09-01

Aneura pinguis is one of the liverwort species complexes that consist of several cryptic species. Ten samples collected from different regions in Poland are in the focus of our research. Eight of the A. pinguis complex belonging to four cryptic species (A, B, C, E) and two samples of closely related species Aneura maxima were tested for the composition of volatile compounds. The HS-SPME technique coupled to GC/FID and GC/MS analysis has been applied. The fiber coated with DVB/CAR/PDMS has been used. The results of the present study, revealed the qualitative and quantitative differences in the composition of the volatile compounds between the studied species. Mainly they are from the group of sesquiterpenoids, oxygenated sesquiterpenoids and aliphatic hydrocarbons. The statistical methods (CA and PCA) showed that detected volatile compounds allow to distinguish cryptic species of A. pinguis. All examined cryptic species of the A. pinguis complex differ from A. maxima. Species A and E of A. pinguis, in CA and PCA, form separate clusters remote from two remaining cryptic species of A. pinguis (B and C) and A. maxima. Relationship between the cryptic species appeared from the chemical studies are in accordance with that revealed on the basis of DNA sequences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Volatile profile, lipid oxidation and protein oxidation of irradiated ready-to-eat cured turkey meat products

International Nuclear Information System (INIS)

Feng, Xi; Ahn, Dong Uk

2016-01-01

Irradiation had little effects on the thiobarbituric acid reactive substances (TBARS) values in ready-to-eat (RTE) turkey meat products, while it increased protein oxidation at 4.5 kGy. The volatile profile analyses indicated that the amount of sulfur compounds increased linearly as doses increased in RTE turkey meat products. By correlation analysis, a positive correlation was found between benzene/ benzene derivatives and alcohols with lipid oxidation, while aldehydes, ketones and alkane, alkenes and alkynes were positively correlated with protein oxidation. Principle component analysis showed that irradiated meat samples can be discriminated by two categories of volatile compounds: Strecker degradation products and radiolytic degradation products. The cluster analysis of volatile data demonstrated that low-dose irradiation had minor effects on the volatile profile of turkey sausages (<1.5 kGy). However, as the doses increased, the differences between the irradiated and non-irradiated cured turkey products became significant. - Highlights: • Irradiation had little effects on lipid oxidation of ready-to-eat cured turkey. • 4.5 kGy irradiation increased protein oxidation. • Irradiated samples were isolated due to Strecker/radiolytic degradation products. • 1.5 kGy irradiation had limited effects on the volatile profile of turkey sausages. • Dimethyl disulfide can be used as a potential marker for irradiated meat products.

Release of volatile compounds from polymeric microcapsules mediated by photocatalytic nanoparticles

OpenAIRE

Marques, Juliana Filipa Gouveia; Oiveira, L. Filipa; Pinto, Renato; Coutinho, Paulo J. G.; Parpot, Pier; Gois, J. R.; Coelho, J. F. J.; Magalhães, F. D.; Tavares, C. J.

2013-01-01

In this study we propose a suitable method for the solar-activated controlled release of volatile compounds from polymeric microcapsules bonded with photocatalytic nanoparticles. These reservoirs can find applications, for example, in the controlled release of insecticides, repellents, or fragrances, amongst other substances. The surfaces of the microcapsules have been functionalized with TiO2 nanoparticles.Upon ultraviolet irradiation, redox mechanisms are initiated on the semicondu...

Geographical provenance of palm oil by fatty acid and volatile compound fingerprinting techniques

NARCIS (Netherlands)

Tres, A.; Ruiz - Samblas, C.; Veer, van der G.; Ruth, van S.M.

2013-01-01

Analytical methods are required in addition to administrative controls to verify the geographical origin of vegetable oils such as palm oil in an objective manner. In this study the application of fatty acid and volatile organic compound fingerprinting in combination with chemometrics have been

Effect of aircraft exhaust sulfur emissions on near field plume aerosols

Energy Technology Data Exchange (ETDEWEB)

Brown, R.C.; Miake-Lye, R.C.; Anderson, M.R.; Kolb, C.E. [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

1997-12-31

Based on estimated exit plane sulfur speciation, a two dimensional, axisymmetric flow field model with coupled gas phase oxidation kinetics and aerosol nucleation and growth dynamics is used to evaluate the effect of fuel sulfur oxidation in the engine on the formation and growth of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols in the near field plume. The conversion of fuel sulfur to sulfur trioxide and sulfuric acid in the engine is predicted to significantly increase the number density and surface area density of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols and the chemical activation of exhaust soot particulates. This analysis indicates the need for experimental measurements of exhaust SO{sub x} emissions to fully assess the atmospheric impact of aircraft emissions. (author) 18 refs.; Submitted to Geophysical Research Letters

Effect of aircraft exhaust sulfur emissions on near field plume aerosols

Energy Technology Data Exchange (ETDEWEB)

Brown, R C; Miake-Lye, R C; Anderson, M R; Kolb, C E [Aerodyne Research, Inc., Billerica, MA (United States). Center for Chemical and Environmental Physics

1998-12-31

Based on estimated exit plane sulfur speciation, a two dimensional, axisymmetric flow field model with coupled gas phase oxidation kinetics and aerosol nucleation and growth dynamics is used to evaluate the effect of fuel sulfur oxidation in the engine on the formation and growth of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols in the near field plume. The conversion of fuel sulfur to sulfur trioxide and sulfuric acid in the engine is predicted to significantly increase the number density and surface area density of volatile H{sub 2}SO{sub 4}/H{sub 2}O aerosols and the chemical activation of exhaust soot particulates. This analysis indicates the need for experimental measurements of exhaust SO{sub x} emissions to fully assess the atmospheric impact of aircraft emissions. (author) 18 refs.; Submitted to Geophysical Research Letters

Effects of irradiation on the volatile compounds of garlic (Allium sativum L)

International Nuclear Information System (INIS)

Wu, J.J.; Yang, J.S.; Liu, M.S.

1996-01-01

The effects of 0.15 kGy gamma irradiation on the content of volatile compounds in garlic bulbs during storage at room temperature were evaluated. The content of diallyl disulphide decreased immediately after irradiation. However, at the end of 8-month storage both irradiated and unirradiated samples showed a significant increase in diallyl disulphide

Comparative study of anthocyanin and volatile compounds content of four varieties of Mexican roselle (Hibiscus sabdariffa L.) by multivariable analysis.

Science.gov (United States)

Camelo-Méndez, G A; Ragazzo-Sánchez, J A; Jiménez-Aparicio, A R; Vanegas-Espinoza, P E; Paredes-López, O; Del Villar-Martínez, A A

2013-09-01

Anthocyanins are a group of water-soluble pigments that provide red, purple or blue color to the leaves, flowers, and fruits. In addition, benefits have been attributed to hypertension and cardiovascular diseases. This study compared the content of total anthocyanins and volatile compounds in aqueous and ethanolic extracts of four varieties of Mexican roselle, with different levels of pigmentation. The multivariable analysis of categorical data demonstrated that ethanol was the best solvent for the extraction of both anthocyanins and volatile compounds. The concentration of anthocyanin in pigmented varieties ranged from 17.3 to 32.2 mg of cyanidin 3-glucoside/g dry weight, while volatile compounds analysis showed that geraniol was the main compound in extracts from the four varieties. The principal component analysis (PCA) allowed description of results with 77.38% of variance establishing a clear grouping for each variety in addition to similarities among some of these varieties. These results were validated by the confusion matrix obtained in the classification by the factorial discriminate analysis (FDA); it can be useful for roselle varieties classification. Small differences in anthocyanin and volatile compounds content could be detected, and it may be of interest for the food industry in order to classify a new individual into one of several groups using different variables at once.

A fast and simple method for quantitative determination of fat-derived medium and low-volatile compounds in cheese

NARCIS (Netherlands)

Alewijn, M.; Sliwinski, E.L.; Wouters, J.T.M.

2003-01-01

Cheese flavour is a mixture of many (volatile) compounds, mostly formed during ripening. The current method was developed to qualify and quantify fat-derived compounds in cheese. Cheese samples were extracted with acetonitrile, which led to a concentrated solution of potential favour compounds,

Research on release rate of volatile organic compounds in typical vessel cabin

Directory of Open Access Journals (Sweden)

ZHANG Jinlan

2018-02-01

Full Text Available [Objectives] Volatile Organic Compounds (VOC should be efficiently controlled in vessel cabins to ensure the crew's health and navigation safety. As an important parameter, research on release rate of VOCs in cabins is required. [Methods] This paper develops a method to investigate this parameter of a ship's cabin based on methods used in other closed indoor environments. A typical vessel cabin is sampled with Tenax TA tubes and analyzed by Automated Thermal Desorption-Gas Chromatography-Mass Spectrometry (ATD-GC/MS. The lumped mode is used and the release rate of Benzene, Toluene, Ethylbenzene and Xylene (BTEX, the typical representatives of VOCs, is obtained both in closed and ventilated conditions. [Results] The results show that the content of xylene and Total Volatile Organic Compounds (TVOC exceed the indoor environment standards in ventilated conditions. The BTEX release rate is similar in both conditions except for the benzene. [Conclusions] This research builds a method to measure the release rate of VOCs, providing references for pollution character evaluation and ventilation and purification system design.

Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

Science.gov (United States)

Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

2013-01-01

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

Preliminary results of measurements of air pollution caused by sulfur compounds near the Polaniec power plant

Energy Technology Data Exchange (ETDEWEB)

Dziewanski, J; Kasina, S; Lewinska, J; Piorek, S

1976-01-01

In the past investigations of the negative impact of power stations on the natural environment have been restricted to measuring sulfur dioxide content in the air. A method of determining complex influence of sulfur compounds on the natural environment is proposed. The following indexes are used: content of sulfur dioxide in the air, dust content (determined by means of the West-Gaeke method), content of sulphate ions in precipitation and pH value of precipitation. Methods used to determine each of the indexes are described. Location of measuring stations in the area where the power station is being constructed is evaluated, taking into account prevailing wind direction and atmospheric conditions (15 measuring points out of which 10 stations measure sulfur content in precipitation and pH value of precipitation, and 5 stations measure the mean daily concentration of sulfur dioxide and dust content). Results are presented in 3 maps, 1 table and 2 pictures. Variations in sulfur dioxide content, dust content, and pH value of precipitation depending on direction of wind, atmospheric conditions and season are analyzed. The results of the investigation will be compared with results of investigations carried out when the power station is in operation. (15 refs.)

Identification of a New Antibacterial Sulfur Compound from Raphanus sativus Seeds

Directory of Open Access Journals (Sweden)

Jeries Jadoun

2016-01-01

Full Text Available Raphanus sativus L. (radish, a member of Brassicaceae, is widely used in traditional medicine in various cultures for treatment of several diseases and disorders associated with microbial infections. The antibacterial activity of the different plant parts has been mainly attributed to several isothiocyanate (ITC compounds. However, the low correlation between the ITC content and antibacterial activity suggests the involvement of other unknown compounds. The objective of this study was to investigate the antibacterial potential of red radish seeds and identify the active compounds. A crude ethanol seed extract was prepared and its antibacterial activity was tested against five medically important bacteria. The ethanol extract significantly inhibited the growth of all tested strains. However, the inhibitory effect was more pronounced against Streptococcus pyogenes and Escherichia coli. Bioassay-guided fractionation of the ethanol extract followed by HPLC, 1H-NMR, 13C-NMR, 15N-NMR, and HMBC analysis revealed that the active fraction consisted of a single new compound identified as [5-methylsulfinyl-1-(4-methylsulfinyl-but-3-enyl-pent-4-enylidene]-sulfamic acid, which consisted of two identical sulfur side chains similar to those found in ITCs. The minimal inhibitory concentration values of the isolated compound were in the range of 0.5–1 mg/mL. These results further highlight the role of radish as a rich source of antibacterial compounds.

Effect of wild strains used as starter cultures and adjunct cultures on the volatile compounds of the Pecorino Siciliano cheese.

Science.gov (United States)

Randazzo, C L; Pitino, I; De Luca, S; Scifò, G O; Caggia, C

2008-03-20

The effect of six wild strains on the volatile profile of the PS cheese was investigated and compared to that generated from industrial starters generally used to produce PS cheese. All cheeses were subjected to microbiological, physicochemical, and volatile compounds analyses. The DGGE of the 16S rDNA analysis was also applied. The volatile compounds generated during ripening were studied through the SPME and the GC-MS methods. No difference was detected between the experimental and control cheeses throughout chemical and microbiological analyses, while the DGGE results showed the presence of Streptococcus thermophilus in all cheeses, and the dominance of Enterococcus durans, Lactobacillus rhamnosus, and Lactobacillus casei in most of the experimental cheeses. Moreover, the presence of Lactococcus lactis species as in the control and in the experimental P2 and P4 cheeses was also revealed. The SPME results showed more pronounced volatile compounds in the experimental cheese samples than in the control ones.

Photodecomposition of volatile organic compounds using TiO2 nanoparticles.

Science.gov (United States)

Jwo, Ching-Song; Chang, Ho; Kao, Mu-Jnug; Lin, Chi-Hsiang

2007-06-01

This study examined the photodecomposition of volatile organic compounds (VOCs) using TiO2 catalyst fabricated by the Submerged Arc Nanoparticle Synthesis System (SANSS). TiO2 catalyst was employed to decompose volatile organic compounds and compare with Degussa-P25 TiO2 in terms of decomposition efficiency. In the electric discharge manufacturing process, a Ti bar, applied as the electrode, was melted and vaporized under high temperature. The vaporized Ti powders were then rapidly quenched under low-temperature and low-pressure conditions in deionized water, thus nucleating and forming nanocrystalline powders uniformly dispersed in the base solvent. The average diameter of the TiO2 nanoparticles was 20 nm. X-ray diffraction analysis confirmed that the nanoparticles in the deionized water were Anatase type TiO2. It was found that gaseous toluene exposed to UV irradiation produced intermediates that were even harder to decompose. After 60-min photocomposition, Degussa-P25 TiO2 reduced the concentration of gaseous toluene to 8.18% while the concentration after decomposition by SANSS TiO2 catalyst dropped to 0.35%. Under UV irradiation at 253.7 +/- 184.9 nm, TiO2 prepared by SANSS can produce strong chemical debonding energy, thus showing great efficiency, superior to that of Degussa-P25 TiO2, in decomposing gaseous toluene and its intermediates.

Influence of partial replacement of NaCl with KCl on profiles of volatile compounds in dry-cured bacon during processing.

Science.gov (United States)

Wu, Haizhou; Zhuang, Hong; Zhang, Yingyang; Tang, Jing; Yu, Xiang; Long, Men; Wang, Jiamei; Zhang, Jianhao

2015-04-01

This study investigated the influence of partial substitution of NaCl with KCl on the formation of volatile compounds in bacons during processing using a purge and trap dynamic headspace GC/MS system. Three substitutions were 0% KCl (I), 40% KCl (II), and 70% KCl (III). The profiles of the volatile compounds significantly changed during processing, particularly during the drying/ripening. At the end of process, the bacons from substitution III formed significantly higher levels of lipid-derived volatiles, such as straight chain aldehydes, hydrocarbons than bacons from substitution I and II, whereas the latter formed higher levels of volatiles from amino acid degradation such as 3-methylbutanal. There were very few differences in volatile formation between 0% and 40% KCl application. These results suggest that K(+) substitution of Na(+) by more than 40% may significantly change profiles of volatiles in finished dry-cured bacons and therefore would result in changes in the product aroma and/or flavour. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of drying and irradiation on the composition of volatile compounds of thyme (Thymus vulgaris L.)

International Nuclear Information System (INIS)

Venskutonis, R.; Poll, L.; Larsen, M.

1996-01-01

An investigation of the influence of air-drying, freeze-drying, γ- and β-irradiation and storage for up to 10 months on the composition of volatile compounds in thyme herb (Thymus vulgaris L.) is presented. Altogether, 70 constituents were identified (53 positively and 17 tentatively), including those considered most important for thyme flavour. Quantitative results did not reveal significant differences in the composition of irradiated and non-irradiated samples, and the reduction of the amount of some volatile compounds after drying was comparable for air-dried and freeze-dried herb. The largest changes in flavour composition were observed during storage, especially the reduction in the concentration of monoterpene hydrocarbons

Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array

International Nuclear Information System (INIS)

Kramer, Kirsten E.; Rose-Pehrsson, Susan L.; Hammond, Mark H.; Tillett, Duane; Streckert, Holger H.

2007-01-01

Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO 2 , H 2 S, and CS 2 in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO 2 , H 2 S, and CS 2 , respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

Detection and classification of gaseous sulfur compounds by solid electrolyte cyclic voltammetry of cermet sensor array.

Science.gov (United States)

Kramer, Kirsten E; Rose-Pehrsson, Susan L; Hammond, Mark H; Tillett, Duane; Streckert, Holger H

2007-02-12

Electrochemical sensors composed of a ceramic-metallic (cermet) solid electrolyte are used for the detection of gaseous sulfur compounds SO(2), H(2)S, and CS(2) in a study involving 11 toxic industrial chemical (TIC) compounds. The study examines a sensor array containing four cermet sensors varying in electrode-electrolyte composition, designed to offer selectivity for multiple compounds. The sensors are driven by cyclic voltammetry to produce a current-voltage profile for each analyte. Raw voltammograms are processed by background subtraction of clean air, and the four sensor signals are concatenated to form one vector of points. The high-resolution signal is compressed by wavelet transformation and a probabilistic neural network is used for classification. In this study, training data from one sensor array was used to formulate models which were validated with data from a second sensor array. Of the 11 gases studied, 3 that contained sulfur produced the strongest responses and were successfully analyzed when the remaining compounds were treated as interferents. Analytes were measured from 10 to 200% of their threshold-limited value (TLV) according to the 8-h time weighted average (TWA) exposure limits defined by the National Institute of Occupational Safety and Health (NIOSH). True positive classification rates of 93.3, 96.7, and 76.7% for SO(2), H(2)S, and CS(2), respectively, were achieved for prediction of one sensor unit when a second sensor was used for modeling. True positive rates of 83.3, 90.0, and 90.0% for SO(2), H(2)S, and CS(2), respectively, were achieved for the second sensor unit when the first sensor unit was used for modeling. Most of the misclassifications were for low concentration levels (such 10-25% TLV) in which case the compound was classified as clean air. Between the two sensors, the false positive rates were 2.2% or lower for the three sulfur compounds, 0.9% or lower for the interferents (eight remaining analytes), and 5.8% or lower for

Comparison and characterization of volatile compounds as markers of oils stability during frying by HS-SPME-GC/MS and Chemometric analysis.

Science.gov (United States)

Ben Hammouda, Ibtissem; Freitas, Flavia; Ammar, Sonda; Da Silva, M D R Gomes; Bouaziz, Mohamed

2017-11-15

The formation and emission of volatile compounds, including the aldehydes and some toxic compounds of oil samples, ROPO pure (100%) and the blended ROPO/RCO (80-20%), were carried out during deep frying at 180°C. The volatile profile of both oil samples was evaluated by an optimized HS-SPME-GC/MS method, before and after 20, 40 and 60 successive sessions of deep-frying. Actually, from 100 detected compounds, aldehydes were found to be the main group formed. In addition, the oil degradation under thermal treatment regarding the volatile compounds were evaluated and compared. Consequently, the blended ROPO/RCO revealed fewer formations of unsaturated aldehydes, including toxic ones, such as acrolein, and showed a greater stability against oxidative thermal degradation compared to ROPO pure. Copyright © 2017 Elsevier B.V. All rights reserved.

Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

Energy Technology Data Exchange (ETDEWEB)

Rodolfo Sosa, E. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Humberto Bravo, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico)], E-mail: hbravo@servidor.unam.mx; Violeta Mugica, A. [Universidad Autonoma Metropolitana, Azcapotzalco, D.F. (Mexico); Pablo Sanchez, A. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, C.P. 04510, D.F. (Mexico); Emma Bueno, L. [Centro Nacional de Investigacion y Capacitacion Ambiental, Instituto Nacional de Ecologia (Mexico); Krupa, Sagar [Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108 (United States)

2009-03-15

Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City.

Levels and source apportionment of volatile organic compounds in southwestern area of Mexico City

International Nuclear Information System (INIS)

Rodolfo Sosa, E.; Humberto Bravo, A.; Violeta Mugica, A.; Pablo Sanchez, A.; Emma Bueno, L.; Krupa, Sagar

2009-01-01

Thirteen volatile organic compounds (VOCs) were quantified at three sites in southwestern Mexico City from July 2000 to February 2001. High concentrations of different VOCs were found at a Gasoline refueling station (GS), a Condominium area (CA), and at University Center for Atmospheric Sciences (CAS). The most abundant VOCs at CA and CAS were propane, n-butane, toluene, acetylene and pentane. In comparison, at GS the most abundant were toluene, pentane, propane, n-butane, and acetylene. Benzene, a known carcinogenic compound had average levels of 28, 35 and 250 ppbC at CAS, CA, and GS respectively. The main contributing sources of the measured VOCs at CA and CAS were the handling and management of LP (Liquid Propane) gas, vehicle exhaust, asphalt works, and use of solvents. At GS almost all of the VOCs came from vehicle exhaust and fuel evaporation, although components of LP gas were also present. Based on the overall results possible abatement strategies are discussed. - Volatile organic compounds were quantified in order to perform their source apportionment in southwestern area of Mexico City

Volatile compounds formation in alcoholic fermentation from grapes collected at 2 maturation stages: Influence of nitrogen compounds and grape variety

OpenAIRE

Martínez-Gil, A. M.; Garde-Cerdán, Teresa; Lorenzo, Cándida; Félix Lara, J.; Pardo, F.; Rosario Salinas, M.

2012-01-01

The aim of this work was to study the influence of nitrogen compounds on the formation of volatile compounds during the alcoholic fermentation carried out with 4 nonaromatic grape varieties collected at 2 different maturation stages. To do this, Monastrell, Merlot, Syrah, and Petit Verdot grapes were collected 1 wk before harvest and at harvest. Then, the musts were inoculated with the same Saccharomyces cerevisiae yeast strain and were fermented in the same winemaking conditions. Amino acids...

Production of volatiles by the red seaweed Gelidium arbuscula (Rhodophyta): emission of ethylene and dimethyl sulfide.

Science.gov (United States)

Garcia-Jimenez, Pilar; Brito-Romano, Olegario; Robaina, Rafael R

2013-08-01

The effects of different light conditions and exogenous ethylene on the emission of volatile compounds from the alga Gelidium arbuscula Bory de Saint-Vincent were studied. Special emphasis was placed on the possibility that the emission of ethylene and dimethyl sulfide (DMS) are related through the action of dimethylsulfoniopropionate (DMSP) lyase. The conversion of DMSP to DMS and acrylate, which is catalyzed by DMSP lyase, can indirectly support the synthesis of ethylene through the transformation of acrylate to ethylene. After mimicking the desiccation of G. arbuscula thalli experienced during low tides, the volatile compounds emitted were trapped in the headspace of 2 mL glass vials for 1 h. Two methods based on gas chromatography/mass spectrometry revealed that the range of organic volatile compounds released was affected by abiotic factors, such as the availability and spectral quality of light, salinity, and exogenous ethylene. Amines and methyl alkyl compounds were produced after exposure to white light and darkness but not after exposure to exogenous ethylene or red light. Volatiles potentially associated with the oxidation of fatty acids, such as alkenes and low-molecular-weight oxygenated compounds, accumu-lated after exposure to exogenous ethylene and red light. Ethylene was produced in all treatments, especially after exposure to exogenous ethylene. Levels of DMS, the most abundant sulfur-compound that was emitted in all of the conditions tested, did not increase after incubation with ethylene. Thus, although DMSP lyase is active in G. arbuscula, it is unlikely to contribute to ethylene synthesis. The generation of ethylene and DMS do not appear to be coordinated in G. arbuscula. © 2013 Phycological Society of America.

Determination of volatile compounds in four commercial samples of Japanese green algae using solid phase microextraction gas chromatography mass spectrometry.

Science.gov (United States)

Yamamoto, Masayoshi; Baldermann, Susanne; Yoshikawa, Keisuke; Fujita, Akira; Mase, Nobuyuki; Watanabe, Naoharu

2014-01-01

Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS), has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera), Tokushima (Ulva prolifera), and Ehime prefecture (Ulva linza). Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera) and Tokushima prefecture (Ulva prolifera). Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum). Multivariant statistical analysis (PCA) enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

Mesoporous thin films of ``molecular squares'' as sensors for volatile organic compounds

Energy Technology Data Exchange (ETDEWEB)

Keefe, M.H.; Slone, R.V.; Hupp, J.T.; Czaplewski, K.F.; Snurr, R.Q.; Stern, C.L.

2000-04-18

Mesoporous thin films of rhenium-based molecular squares, [Re(CO){sub 3}Cl(L)]{sub 4} (L = pyrazine, 4,4{prime}-bipyridine), have been utilized as sensors for volatile organic compounds (VOCs). The sensing was conducted using a quartz crystal microbalance with the target compounds present in the gas phase at concentrations ranging from 0.05 to 1 mM. Quartz crystal microbalance studies with these materials allowed for distinction between the following VOCs: (1) small aromatic versus aliphatic molecules of almost identical size and volatility and (2) an array of benzene molecules derivatized with electron donating/withdrawing substituents. The experiments suggest that the mesoporous host materials interact with VOC guest molecules through both van der Waals and weak charge-transfer interactions. In addition, size selectivity is shown by exposure of the molecular squares to cyclic ethers of differing size.

Distribution, movement, and evolution of the volatile elements in the lunar regolith

International Nuclear Information System (INIS)

Gibson, E.K. Jr.

1975-01-01

The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the Moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the Moon of these volatile elements are considered. (Auth.)

Distribution, movement, and evolution of the volatile elements in the lunar regolith

Science.gov (United States)

Gibson, E. K., Jr.

1975-01-01

The abundances and distributions of carbon, nitrogen, and sulfur in lunar soils are reviewed. Carbon and nitrogen have a predominantly extra-lunar origin in lunar soils and breccias, while sulfur is mostly indigeneous to the moon. The lunar processes which effect the movement, distribution, and evolution of carbon, nitrogen, and sulfur, along with the volatile alkali elements sodium, potassium, and rubidium during regolith processes are discussed. Possible mechanisms which may result in the addition to or loss from the moon of these volatile elements are considered.

Car indoor air pollution by volatile organic compounds and aldehydes in Japan

Directory of Open Access Journals (Sweden)

Kouichi Tatsu

2016-06-01

Full Text Available Fifty-five organic substances including volatile organic compounds (VOCs and aldehydes present in indoor air were measured from 24 car cabins in Japan. A screening-level risk assessment was also performed. Acetaldehyde (3.81–36.0 μg/m3, formaldehyde (3.26–26.7 μg/m3, n-tetradecane (below the method quantification limit (compounds originated from the car interior materials. Total volatile organic compound (TVOC concentrations in 14 car cabins (58% of all car cabins exceeded the advisable values established by the Ministry of Health, Labour and Welfare of Japan (400 μg/m3. The highest TVOC concentration (1136 μg/m3 was found in a new car (only one month since its purchase date. Nevertheless, TVOC concentrations exceeded the advisable value even for cars purchased over 10 years ago. Hazard quotients (HQs for formaldehyde obtained using measured median and highest concentrations in both exposure scenarios for occupational use (residential time in a car cabin was assumed to be 8 h were higher than that expected, a threshold indicative of potential adverse effects. Under the same exposure scenarios, HQ values for all other organic compounds remained below this threshold.

Sulfur-Kβ /sub emission studies on sulfur-bearing heterocycles

International Nuclear Information System (INIS)

Phillips, D.R.; Andermann, G.G.; Fujiwara, F.

1986-01-01

Sulfur-K/β /sub x-ray fluorescence spectroscopy (XFS) has been used to study the electronic structure and bonding in sulfur-bearing heterocycles. XFS not only has the capability of experimentally measuring valence electron energies in molecular species, but can also provide intensity data which can help define the nature of the molecular orbitals defined by the electrons. This report discusses the feasibility of using XFS as an analytical tool for the determination of total and specific sulfur heterocycle content in samples. A variety of compounds were studied. These include thiophene, thiophene derivatives, tetranydrothiophene, several more complex saturated and unsaturated sulfur heterocycles, and heterocycles containing both sulfur and nitrogen. The sulfur-K/β /sub spectra were obtained using a double crystal spectrometer which provided an instrumental resolution of about 0.7 eV

Head Space Solid Phase Micro-Extraction (HS - SPME of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636

Directory of Open Access Journals (Sweden)

Eunice Valduga

2010-12-01

Full Text Available The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636 using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME. Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm, temperature (25-60 ºC, extraction time (10-30 minutes, and sample volume (2-3 mL. The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD. The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v. In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm, temperature (23-33 ºC, pH (4.0-8.0, precursor concentration (0.02-0.1%, mannitol (0-6%, and asparagine concentration (0-0.2% was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

Do the organic sulfur compounds DMSP and DMS drive coral microbial associations?

Science.gov (United States)

Raina, Jean-Baptiste; Dinsdale, Elizabeth A; Willis, Bette L; Bourne, David G

2010-03-01

Dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) are key compounds in the global sulfur cycle. Moreover, DMS is particularly important in climate regulation owing to its role in cloud formation. Reef building corals are major contributors to the production of these two compounds and also form diverse and complex associations with bacteria, which are known to play a crucial role in the degradation of DMSP and DMS. Here, we highlight an extensive overlap between bacterial species implicated in DMSP/DMS degradation and those associated with corals, leading to the hypothesis that these two compounds play a major role in structuring coral-associated bacterial communities, with important consequences for coral health and the resilience of coral reefs. We also explore the publically available metagenome databases and show that genes implicated in DMSP metabolism are abundant in the viral component of coral-reef-derived metagenomes, indicating that viruses can act as a reservoir for such genes.

A POLYMER-CERAMIC COMPOSITE MEMBRANE FOR RECOVERING VOLATILE ORGANIC COMPOUNDS FROM WASTEWATERS BY PERVAPORATION

Science.gov (United States)

A composite membrane was constructed on a porous ceramic support from a block copolymer of styrene and butadiene (SBS). It was tested in a laboratory pervaporation apparatus for recovering volatile organic compounds (VOCs) such a 1,1,1-trichloroethane (TCA) and trichloroethylene ...

(Semi)volatile organic compounds and microbiological entities in snow during OASIS Barrow 2009

Science.gov (United States)

Ariya, P.; Kos, G.

2009-12-01

Gregor Kos (1), Nafissa Adechina (2), Dwayne Lutchmann (2) , Roya Mortazavi, and Parisa Ariya* (1), (2) (1) McGill University, Department of Atmospheric and Oceanic Sciences, 805 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada (2) McGill University, Department of Chemistry, 801 Sherbrooke Street West, Montreal, Quebec, H3A 2K6, Canada an active medium for the deposition of (semi-)volatile (bio)organic compounds. We collected surface snow samples during the OASIS Barrow campaign in March 2009 for analysis of semi-volatile organic compounds using solid phase microextraction and gas chromatography with mass spectrometric detection (SPME-GC/MS). Additioal gab samples were taken for analysis of non-methane hydrocarbons in air. More over, we analyzed for microbial species in air and snow. Identifed organic compounds covered a wide range of functionalities andmolecular weigts, including oxygenated reactive speces such as aldehydes (e.g., hexanal to decanal), alcohols (e.g., hexanol, octanol) and aromatic species (e.g., methyl- and ethylbenzenes). Quantification data for selected aromatic species are presented with concentrations in the upper ng/L range. We will present our preliminary data on microbiological species, and will discuss the potential mplications of the results for organic snow chemistry.

Emissions of volatile organic compounds (VOCs) from concentrated animal feeding operations (CAFOs): chemical compositions and separation of sources

Science.gov (United States)

Yuan, Bin; Coggon, Matthew M.; Koss, Abigail R.; Warneke, Carsten; Eilerman, Scott; Peischl, Jeff; Aikin, Kenneth C.; Ryerson, Thomas B.; de Gouw, Joost A.

2017-04-01

Concentrated animal feeding operations (CAFOs) emit a large number of volatile organic compounds (VOCs) to the atmosphere. In this study, we conducted mobile laboratory measurements of VOCs, methane (CH4) and ammonia (NH3) downwind of dairy cattle, beef cattle, sheep and chicken CAFO facilities in northeastern Colorado using a hydronium ion time-of-flight chemical-ionization mass spectrometer (H3O+ ToF-CIMS), which can detect numerous VOCs. Regional measurements of CAFO emissions in northeastern Colorado were also performed using the NOAA WP-3D aircraft during the Shale Oil and Natural Gas Nexus (SONGNEX) campaign. Alcohols and carboxylic acids dominate VOC concentrations and the reactivity of the VOCs with hydroxyl (OH) radicals. Sulfur-containing and phenolic species provide the largest contributions to the odor activity values and the nitrate radical (NO3) reactivity of VOC emissions, respectively. VOC compositions determined from mobile laboratory and aircraft measurements generally agree well with each other. The high time-resolution mobile measurements allow for the separation of the sources of VOCs from different parts of the operations occurring within the facilities. We show that the emissions of ethanol are primarily associated with feed storage and handling. Based on mobile laboratory measurements, we apply a multivariate regression analysis using NH3 and ethanol as tracers to determine the relative importance of animal-related emissions (animal exhalation and waste) and feed-related emissions (feed storage and handling) for different VOC species. Feed storage and handling contribute significantly to emissions of alcohols, carbonyls, carboxylic acids and sulfur-containing species. Emissions of phenolic species and nitrogen-containing species are predominantly associated with animals and their waste.

Volatile compounds responsible for aroma of Jutrzenka liquer wine.

Science.gov (United States)

Jeleń, Henryk H; Majcher, Małgorzata; Dziadas, Mariusz; Zawirska-Wojtasiak, Renata; Czaczyk, Katarzyna; Wąsowicz, Erwin

2011-10-21

Jutrzenka is a sweet liquer wine produced in Poland from the grape variety of the same name, developed in Poland to withstand the harsh climate of winery regions. Jutrzenka wine has a characteristic aroma with strong fruity and flowery notes, which make it unique among other liquer wines as demonstrated in sensory profile analysis. The work was aimed at characterization of volatile compounds in this wine, with the emphasis on characterization of compounds responsible for its unique aroma. Gas chromatography-olfactometry (GC-O) was applied to identify the key odorants using aroma extract dilution analysis (AEDA) approach. To facilitate free and bound terpenes and C(13)-norisoprenoids identification solid phase extraction (SPE) was used followed by GC/MS. Among identified key odorants β-damascenone was the compound having the highest FD (4096), followed by isoamyl alcohol, 4-mercapto-4-methyl-2-pentanone (FD=2048), methional, linalool, ethyl decanoate (FD=1024) and ethyl hexanoate, furaneol (FD=512). Other significant compounds were ethyl 2-methyl propanoate, ethyl 2-methylbutanoate and phenyl ethyl alcohol. Determination of odor activity values (OAV) showed the highest values for β-damascenone (566), 4-mercapto-4-methyl-2-pentanone (288) ethyl hexanoate (32) and linalool (7). Jutrzenka exhibited also a rich profile of free, and to lesser extent bound terpenes. Copyright © 2011 Elsevier B.V. All rights reserved.

Impact of Sucrose Addition on the Physiochemical Properties and Volatile Compounds of “Shuangyou” Red Wines

Directory of Open Access Journals (Sweden)

Huan Liu

2017-01-01

Full Text Available “Shuangyou,” a Vitis amurensis Rupr. variety, is widely cultivated in northeastern and western China. Its berries have high acidity and low sugar content. In this study, different proportions of sucrose were added to the must samples during fermentation to investigate the effect of sugar on the physicochemical properties and volatile compounds of “Shuangyou” wines. The addition of sucrose significantly improved yeast growth and alcohol production, altered the color qualities, and slightly decreased titratable acidity during fermentation. The highest tested proportion of added sucrose resulted in the highest maximum yeast counts and final ethanol concentrations. Moreover, 37 volatile compounds (esters, alcohols, fatty acids, ketones, and aldehydes were identified and quantified by solid-phase microextraction with gas chromatography-mass spectrometry. The concentrations of these compounds were correlated with the addition of sucrose. Furthermore, the addition of 100 g/L sucrose was sufficient for improving the concentrations of the aromatic compounds. The increase in ester, alcohol, and fatty acid concentration led to a positive OAVs impact (odor activity value > 1 at the end of fermentation.

New procedure for the control of the treatment of industrial effluents to remove volatile organosulfur compounds.

Science.gov (United States)

Boczkaj, Grzegorz; Makoś, Patrycja; Fernandes, André; Przyjazny, Andrzej

2016-10-01

We present a new procedure for the determination of volatile organosulfur compounds in samples of industrial effluents using dispersive liquid-liquid microextraction and gas chromatography with flame photometric detection. Initially, the extraction parameters were optimized. These included: type and volume of extraction solvent, volume of disperser solvent, salting out effect, pH, time and speed of centrifugation as well as extraction time. The procedure was validated for 30 compounds. The developed procedure has low detection limits of 0.0071-0.49 μg/L and a good precision (relative standard deviation values of 1.2-5.0 and 0.6-4.1% at concentrations of 1 and 10 μg/L, respectively). The procedure was used to determine the content of volatile organosulfur compounds in samples of effluents from the production of bitumens before and after chemical treatment, in which six compounds were identified, including 2-mercaptoethanol, thiophenol, thioanisole, dipropyl disulfide, 1-decanethiol, and phenyl isothiocyanate at concentrations ranging from 0.47 to 8.89 μg/L. Problems in the determination of organosulfur compounds related to considerable changes in composition of the effluents, increase in concentration of individual compounds and appearance of secondary pollutants during effluent treatment processes are also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of Volatile Compounds in Four Commercial Samples of Japanese Green Algae Using Solid Phase Microextraction Gas Chromatography Mass Spectrometry

Directory of Open Access Journals (Sweden)

Masayoshi Yamamoto

2014-01-01

Full Text Available Green algae are of great economic importance. Seaweed is consumed fresh or as seasoning in Japan. The commercial value is determined by quality, color, and flavor and is also strongly influenced by the production area. Our research, based on solid phase microextraction gas chromatography mass spectrometry (SPME-GC-MS, has revealed that volatile compounds differ intensely in the four varieties of commercial green algae. Accordingly, 41 major volatile compounds were identified. Heptadecene was the most abundant compound from Okayama (Ulva prolifera, Tokushima (Ulva prolifera, and Ehime prefecture (Ulva linza. Apocarotenoids, such as ionones, and their derivatives were prominent volatiles in algae from Okayama (Ulva prolifera and Tokushima prefecture (Ulva prolifera. Volatile, short chained apocarotenoids are among the most potent flavor components and contribute to the flavor of fresh, processed algae, and algae-based products. Benzaldehyde was predominant in seaweed from Shizuoka prefecture (Monostroma nitidum. Multivariant statistical analysis (PCA enabled simple discrimination of the samples based on their volatile profiles. This work shows the potential of SPME-GC-MS coupled with multivariant analysis to discriminate between samples of different geographical and botanical origins and form the basis for development of authentication methods of green algae products, including seasonings.

Biodegradation tests of mercaptocarboxylic acids, their esters, related divalent sulfur compounds and mercaptans.

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Rücker, Christoph; Mahmoud, Waleed M M; Schwartz, Dirk; Kümmerer, Klaus

2018-04-17

Mercaptocarboxylic acids and their esters, a class of difunctional compounds bearing both a mercapto and a carboxylic acid or ester functional group, are industrial chemicals of potential environmental concern. Biodegradation of such compounds was systematically investigated here, both by literature search and by experiments (Closed Bottle Test OECD 301D and Manometric Respirometry Test OECD 301F). These compounds were found either readily biodegradable or at least biodegradable to a significant extent. Some related compounds of divalent sulfur were tested for comparison (mercaptans, sulfides, disulfides). For the two relevant monofunctional compound classes, carboxylic acids/esters and mercaptans, literature data were compiled, and by comparison with structurally similar compounds without these functional groups, the influence of COOH/COOR' and SH groups on biodegradability was evaluated. Thereby, an existing rule of thumb for biodegradation of carboxylic acids/esters was supported by experimental data, and a rule of thumb could be formulated for mercaptans. Concurrent to biodegradation, abiotic processes were observed in the experiments, rapid oxidative formation of disulfides (dimerisation of monomercaptans and cyclisation of dimercaptans) and hydrolysis of esters. Some problems that compromise the reproducibility of biodegradation test results were discussed.

Mixing-assisted oxidative desulfurization of model sulfur compounds using polyoxometalate/H2O2 catalytic system

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Angelo Earvin Sy Choi

2016-07-01

Full Text Available Desulfurization of fossil fuel derived oil is needed in order to comply with environmental regulations. Dibenzothiophene and benzothiophene are among the predominant sulfur compound present in raw diesel oil. In this study, mixing-assisted oxidative desulfurization of dibenzothiophene and benzothiophene were carried out using polyoxometalate/H2O2 systems and a phase transfer agent. The effects of reaction time (2–30 min and temperature (30–70 °C were examined in the oxidation of model sulfur compounds mixed in toluene. A pseudo first-order reaction kinetic model and the Arrhenius equation were utilized in order to evaluate the kinetic rate constant and activation energy of each catalyst tested in the desulfurization process. Results showed the order of catalytic activity and activation energy of the different polyoxometalate catalysts to be H3PW12O40 > H3PM12O40 > H4SiW12O40 for both dibenzothiophene and benzothiophene.

Changes in volatile compounds in whey protein concentrate stored at elevated temperature and humidity

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Whey protein concentrate (WPC) has been recommended for use in emergency aid programs, but it is often stored overseas without temperature and relative humidity (RH) control, which may cause it to be rejected because of yellowing, off-flavors, or clumping. Therefore, the volatile compounds present ...

Emission index for evaluation of volatile organic compounds emitted from tomato plants in greenhouses

NARCIS (Netherlands)

Takayama, K.; Jansen, R.M.C.; Henten, van E.J.; Verstappen, F.W.A.; Bouwmeester, H.J.; Nishina, H.

2012-01-01

Measurement of volatile organic compounds (VOCs) emitted by plants allows us to monitor plant health status without touching the plant. To bring this technique a step further towards a practical plant diagnosis technique for greenhouse crop production, we have defined a numerical index named

Modeling of volatile and phenolic compounds and optimization of the process conditions for obtaining balanced extra virgin olive oils

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A. M. Vidal

2018-06-01

Full Text Available The main objective of this paper is to obtain extra virgin olive oils (EVOOs which are balanced in volatile and phenolic compounds. An experimental design was performed and response surface methodology was applied. The factors for malaxation were: temperature 20-40 °C, time 30-90 min, and hole diameter of hammer-crusher 4.5-6.5 mm. The results show that high temperatures and small hole diameter must be used in order to obtain a higher content in phenolic compounds, while for volatile compounds a low temperature and large hole diameter must be used. The models predict that the best and more balanced EVOO are obtained with the hole diameter of greater size and a medium-low temperature. Thus, for a hammer-crusher hole diameter of 6.5 mm 337 and 356 mg/kg total HPLC phenols were obtained for malaxation temperature of 20 and 25 °C, respectively and, likewise, 12.7 and 11.5 mg/kg total LOX volatiles.

Ionic liquid technology to recover volatile organic compounds (VOCs).

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Salar-García, M J; Ortiz-Martínez, V M; Hernández-Fernández, F J; de Los Ríos, A P; Quesada-Medina, J

2017-01-05

Volatile organic compounds (VOCs) comprise a wide variety of carbon-based materials which are volatile at relatively low temperatures. Most of VOCs pose a hazard to both human health and the environment. For this reason, in the last years, big efforts have been made to develop efficient techniques for the recovery of VOCs produced from industry. The use of ionic liquids (ILs) is among the most promising separation technologies in this field. This article offers a critical overview on the use of ionic liquids for the separation of VOCs both in bulk and in immobilized form. It covers the most relevant works within this field and provides a global outlook on the limitations and future prospects of this technology. The extraction processes of VOCs by using different IL-based assemblies are described in detail and compared with conventional methods This review also underlines the advantages and limitations posed by ionic liquids according to the nature of the cation and the anions present in their structure and the stability of the membrane configurations in which ILs are used as liquid phase. Copyright © 2016 Elsevier B.V. All rights reserved.

Farmed and wild sea bass (Dicentrarchus labrax) volatile metabolites: a comparative study by SPME-GC/MS.

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Vidal, Natalia P; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

2016-03-15

Farmed and wild European sea bass (Dicentrarchus labrax) could be distinguished by its volatile metabolites, an issue not addressed until now. The aim of this work was to study these metabolites by solid-phase microextraction followed by gas chromatography/mass spectrometry (SPME-GC/MS). Both farmed and wild sea bass have a great number of volatile metabolites, most of them being in low concentrations. These include alcohols, aldehydes, ketones, alkylfurans, acids, aliphatic and aromatic hydrocarbons, terpenes, sulfur and nitrogen derivatives, 2,6-di-tert-butyl-4-methylphenol and one derived compound, as well as 2,4,7,9-tetramethyl-5-decyne-4,7-diol, this latter compound presumably resulting from environmental contamination. Important differences have been detected between both types of sea bass, and also among individuals inside each group. Farmed specimens are richer in volatile metabolites than the wild counterparts; however, these latter, in general, contain a high number and abundance of metabolites resulting from microbial and enzymatic non-oxidative activity than the former. Clear differences in the volatile metabolites of wild and farmed sea bass have been found. A great deal of valuable information on sea bass volatile metabolites has been obtained, which can be useful in understanding certain aspects of the quality and safety of raw and processed sea bass. © 2015 Society of Chemical Industry.

Non-Saccharomyces Yeasts Nitrogen Source Preferences: Impact on Sequential Fermentation and Wine Volatile Compounds Profile

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Antoine Gobert

2017-11-01

Full Text Available Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has been little studied. With a view to improving the use of non-Saccharomyces yeasts in winemaking, we studied the use of amino acids and ammonium by three strains of non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima, and Pichia membranifaciens in grape juice. We first determined which nitrogen sources were preferentially used by these yeasts in pure cultures at 28 and 20°C (because few data are available. We then carried out sequential fermentations at 20°C with S. cerevisiae, to assess the impact of the non-Saccharomyces yeasts on the availability of assimilable nitrogen for S. cerevisiae. Finally, 22 volatile compounds were quantified in sequential fermentation and their levels compared with those in pure cultures of S. cerevisiae. We report here, for the first time, that non-Saccharomyces yeasts have specific amino-acid consumption profiles. Histidine, methionine, threonine, and tyrosine were not consumed by S. bacillaris, aspartic acid was assimilated very slowly by M. pulcherrima, and glutamine was not assimilated by P. membranifaciens. By contrast, cysteine appeared to be a preferred nitrogen source for all non-Saccharomyces yeasts. In sequential fermentation, these specific profiles of amino-acid consumption by non-Saccharomyces yeasts may account for

Non-Saccharomyces Yeasts Nitrogen Source Preferences: Impact on Sequential Fermentation and Wine Volatile Compounds Profile

Science.gov (United States)

Gobert, Antoine; Tourdot-Maréchal, Raphaëlle; Morge, Christophe; Sparrow, Céline; Liu, Youzhong; Quintanilla-Casas, Beatriz; Vichi, Stefania; Alexandre, Hervé

2017-01-01

Nitrogen sources in the must are important for yeast metabolism, growth, and performance, and wine volatile compounds profile. Yeast assimilable nitrogen (YAN) deficiencies in grape must are one of the main causes of stuck and sluggish fermentation. The nitrogen requirement of Saccharomyces cerevisiae metabolism has been described in detail. However, the YAN preferences of non-Saccharomyces yeasts remain unknown despite their increasingly widespread use in winemaking. Furthermore, the impact of nitrogen consumption by non-Saccharomyces yeasts on YAN availability, alcoholic performance and volatile compounds production by S. cerevisiae in sequential fermentation has been little studied. With a view to improving the use of non-Saccharomyces yeasts in winemaking, we studied the use of amino acids and ammonium by three strains of non-Saccharomyces yeasts (Starmerella bacillaris, Metschnikowia pulcherrima, and Pichia membranifaciens) in grape juice. We first determined which nitrogen sources were preferentially used by these yeasts in pure cultures at 28 and 20°C (because few data are available). We then carried out sequential fermentations at 20°C with S. cerevisiae, to assess the impact of the non-Saccharomyces yeasts on the availability of assimilable nitrogen for S. cerevisiae. Finally, 22 volatile compounds were quantified in sequential fermentation and their levels compared with those in pure cultures of S. cerevisiae. We report here, for the first time, that non-Saccharomyces yeasts have specific amino-acid consumption profiles. Histidine, methionine, threonine, and tyrosine were not consumed by S. bacillaris, aspartic acid was assimilated very slowly by M. pulcherrima, and glutamine was not assimilated by P. membranifaciens. By contrast, cysteine appeared to be a preferred nitrogen source for all non-Saccharomyces yeasts. In sequential fermentation, these specific profiles of amino-acid consumption by non-Saccharomyces yeasts may account for some of the

Morphology and volatile compounds of metathoracic scent gland in Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae).

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Zhao, D; Gao, J; Wang, Y; Jiang, J; Li, R

2012-08-01

Tessaratoma papillosa (Drury) (Hemiptera: Tessaratomidae) is a serious insect pest of litchi and longan in South China. When disturbed, this insect could release large quantities of disagreeable odorous volatiles from its scent gland. Knowledge on the scent gland and its secretion is crucial for developing the semiochemical methods to manage this pest. Morphology and ultrastructure of the metathoracic scent glands (MTGs) were studied under stereo and scanning electron microscopy, and the volatile compounds of MTGs from both male and female T. papillosa were analyzed with coupled gas chromatography-mass spectrometry (GC-MS). The MTG complex is located between the metathorax and the first abdominal segment at the ventral surface of the insect, which has a well-developed single double valve cystic-shaped orange median reservoir, paired colorless lateral glands in both sides, and a long and wavy tubular accessory gland that inlays tightly into the ventral edge around the median reservoir. The MTG opens to the body surface through paired ostioles located between the meso- and metacoxae of the evaporatorium with mushroom bodies. The GC-MS analyses showed that female and male adults have nine major volatile components in common. Tridecane is the most abundant in both females and males, reaching up to 47.1% and 51.8% of relative amount, respectively. The minor component is benzophenone with only 0.28% and 0.14%. Furthermore, undecane, tetradecane, 3-methyl-tridecane, and cyclopentadecane were found only in males. The possible function of volatile compounds of MTG contents in T. papillosa is addressed.

Determination of volatile organic compounds responsible for flavour in cooked river buffalo meat

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A. Di Luccia

2010-02-01

Full Text Available Flavour is an important consumer attractive that directly influences the success of food products on the market. The determination of odorous molecules and their identification allows to useful knowledge for producers to valorise their own products. Buffalo meat has a different chemical composition from pork and beef and requires some cautions in cooking and processing. This work aims at the identification of volatile molecules responsible for flavours in river buffalo meat. The determination was carried out by solid phase micro-extraction (SPME technique and analysed by gas chromatography coupled to mass spectrometry (GC-MS. The most relevant results were the higher odorous impact of buffalo meat and the higher content of sulphide compounds responsible for wild aroma respect to pork and beef. These results were obtained comparing the total area of peaks detected in every chromatogram. We have also found significant differences concerning the contents of pentadecane, 1-hexanol-2 ethyl, butanoic acid, furano-2-penthyl. The origin of volatile organic compounds and their influence on the river buffalo aromas were discussed.

Volatile Compounds and Sensory Evaluation of Spreadable Creams Based on Roasted Sunflower Kernels and Cocoa or Carob Powder

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Emil Racolța

2014-11-01

Full Text Available The known confectionery spreadable cream product category includes well-known cocoa - hazelnut pastes as well as peanut butter, products that became very popular in the last decades due to their pleasant taste and ease of eating. However, health constraints appeared both hazelnut and peanut are food allergens, while cocoa excites central nervous system (CNS and on everyday consumption causes dependence. The aim of this work was to characterize the aroma and sensory of an innovative product that belongs to the same confectionery spreadable cream product category. Six spreadable cream prototypes were produced by using sugar, roasted sunflower kernel, carob or cocoa powder, palm or coconut fat and, lecithin. The obtained samples were firstly analyzed by using the nine point hedonic scale test. The volatile compounds profile analysis (“In Tube Extraction”- GC-MS was performed on the best samples (in terms of sensory containing cocoa or carob powder, as well as a control. The main volatile compound of all three samples was pinene (42-51% which is a characteristic flavor of turpentine, wood. Acetophenone instead (20-25% gives flavors of almond, floral, sweetish. Benzaldehyde (8.11-9.73% is characteristic for almond flavor with hints of caramel. The study revealed that the analyzed spreadable creams have similar volatile profiles, even if carob and cocoa powder showed different volatile compounds profiles, with the major compound for both being Propanoic acid, 2-methyl. Thus, with similar taste to cocoa sample, carob-sunflower spreadable cream is an alternative that not include ingredients with allergic potential or CNS stimulants. 

Profiles of Volatile Flavor Compounds in Milk Fermented with Different Proportional Combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus.

Science.gov (United States)

Dan, Tong; Wang, Dan; Wu, Shimei; Jin, Rulin; Ren, Weiyi; Sun, Tiansong

2017-09-29

Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus are key factors in the fermentation process and the final quality of dairy products worldwide. This study was performed to investigate the effects of the proportions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus isolated from traditionally fermented dairy products in China and Mongolia on the profile of volatile compounds produced in samples. Six proportional combinations (1:1, 1:10, 1:50, 1:100, 1:1000, and 1:10,000) of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 were considered, and the volatiles were identified and quantified by solid-phase microextraction and gas chromatography-mass spectrometry (SPME-GC-MS) against an internal standard. In total, 89 volatile flavor compounds, consisting of aldehydes, ketones, acids, alcohols, esters, and aromatic hydrocarbons, were identified. Among these, some key flavor volatile compounds were identified, including acetaldehyde, 3-methylbutanal, acetoin, 2-heptanone, acetic acid, butanoic acid, and 3-methyl-1-butanol. The of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 influenced the type and concentration of volatiles produced. In particular, aldehydes and ketones were present at higher concentrations in the 1:1000 treatment combination than in the other combinations. Our findings emphasize the importance of selecting the appropriate proportions of L. delbrueckii subsp. bulgaricus and S. thermophilus for the starter culture in determining the final profile of volatiles and the overall flavor of dairy products.

Profiles of Volatile Flavor Compounds in Milk Fermented with Different Proportional Combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus

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Tong Dan

2017-09-01

Full Text Available Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus are key factors in the fermentation process and the final quality of dairy products worldwide. This study was performed to investigate the effects of the proportions of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus isolated from traditionally fermented dairy products in China and Mongolia on the profile of volatile compounds produced in samples. Six proportional combinations (1:1, 1:10, 1:50, 1:100, 1:1000, and 1:10,000 of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 were considered, and the volatiles were identified and quantified by solid-phase microextraction and gas chromatography–mass spectrometry (SPME-GC-MS against an internal standard. In total, 89 volatile flavor compounds, consisting of aldehydes, ketones, acids, alcohols, esters, and aromatic hydrocarbons, were identified. Among these, some key flavor volatile compounds were identified, including acetaldehyde, 3-methylbutanal, acetoin, 2-heptanone, acetic acid, butanoic acid, and 3-methyl-1-butanol. The of L. delbrueckii subsp. bulgaricus IMAU20401 to S. thermophilus ND03 influenced the type and concentration of volatiles produced. In particular, aldehydes and ketones were present at higher concentrations in the 1:1000 treatment combination than in the other combinations. Our findings emphasize the importance of selecting the appropriate proportions of L. delbrueckii subsp. bulgaricus and S. thermophilus for the starter culture in determining the final profile of volatiles and the overall flavor of dairy products.

Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

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Stefanie eMangold

2011-02-01

Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

Emerging site characterization technologies for volatile organic compounds