Non-volatile Organic Compounds Research Articles

Biomolecules produced in liquid-state fermentation by a marine-derived fungus,Penicillium roqueforti.

Screening of biomass of a new marine-derived strain of Penicillium roqueforti, as produced by liquid-state fermentation, led to the identification of several volatile organic compounds active in the fatty acid pathway as well as fragments produced by their catabolism, terpenoids, and metabolites from the shikimic acid pathway. In addition, five non-volatile organic compounds, triolein, ergosterol peroxide, 9(11)-dehydroergosterol peroxide, 4-hydroxybenzaldehyde, and d-mannitol, were isolated and identified by spectroscopy. The results showed that this fungal strain did not produce any mycotoxin in the culture conditions applied, and thus is useful for industrial applications, where high value-added biomolecules are generated.

Exhaled breath analysis for lung cancer.

Early diagnosis of lung cancer results in improved survival compared to diagnosis with more advanced disease. Early disease is not reliably indicated by symptoms. Because investigations such as bronchoscopy and needle biopsy have associated risks and substantial costs, they are not suitable for population screening. Hence new easily applicable tests, which can be used to screen individuals at risk, are required. Biomarker testing in exhaled breath samples is a simple, relatively inexpensive, non-invasive approach. Exhaled breath contains volatile and non-volatile organic compounds produced as end-products of metabolic processes and the composition of such compounds varies between healthy subjects and subjects with lung cancer. Many studies have analysed the patterns of these compounds in exhaled breath. In addition studies have also reported that the exhaled breath condensate (EBC) can reveal gene mutations or DNA abnormalities in patients with lung cancer. This review has summarised the scientific evidence demonstrating that lung cancer has distinct chemical profiles in exhaled breath and characteristic genetic changes in EBC. It is not yet possible to accurately identify individuals with lung cancer in at risk populations by any of these techniques. However, analysis of both volatile organic compounds in exhaled breath and of EBC have great potential to become clinically useful diagnostic and screening tools for early stage lung cancer detection.

What makes Allium species effective against pathogenic microbes?

The antimicrobial activity of garlic (Allium sativum L.) has been known since ancient times. The first citation dates back to the Egyptian period of fifteenth century BC when garlic was reported to be used in folk medicine as a remedy for microbial infections. Scientific investigations on garlic started in 1858 with the work of Pasteur who first noted antibacterial properties of garlic extracts. From that date to the discovery of antibiotics, garlic has been used against amoebic dysentery and epidemic diseases such as typhus, cholera, diphtheria, and tuberculosis. But what makes garlic and Allium species effective against pathogenic microbes? The volatile allicin and other thiosulfinates, giving pungency to Allium plants, are well-studied antimicrobial agents. The thiosulfinates can decompose to form additional sulfur constituents, including diallyl, methyl allyl, and dipropyl mono-, di-, tri- e tetra-sulfides, and (E)- and (Z)-ajoene without losing antimicrobial activity. Besides these compounds, onion and garlic are characterized by polar compounds of steroidal and phenolic origin, often glycosilated, not pungent and more stable during cooking, showing also antimicrobial activity. Recently, there has been increasing scientific attention given to such compounds. Nitrogen organic compounds, like alkaloids and polypeptides, have also been isolated from these plants and have shown antimicrobial activity. In this paper, the literature about the major volatile and non-volatile organic compounds of garlic and other Allium plants has been reviewed. Particular attention is given to the compounds possessing antimicrobial activity and to the correlation between the observed activity and the chemical structure of the tested compounds.

Studying the fate of non-volatile organic compounds in a commercial plasma air purifier

Degradation of non-volatile organic compounds–environmental toxins (methyltriclosane and phenanthrene), bovine serum albumin, as well as bioparticles (Legionella pneumophila, Bacillus subtilis, and Bacillus anthracis)–in a commercially available plasma air purifier based on a cold plasma was studied in detail, focusing on its efficiency and on the resulting degradation products. This system is capable of handling air flow velocities of up to 3.0m s−1 (3200Lmin−1), much higher than other plasma-based reactors described in the literature, which generally are limited to air flow rates below 10Lmin−1. Mass balance studies consistently indicated a reduction in concentration of the compounds/particles after passage through the plasma air purifier, 31% for phenanthrene, 17% for methyltriclosane, and 80% for bovine serum albumin. L. pneumophila did not survive passage through the plasma air purifier, and cell counts of aerosolized spores of B. subtilis and B. anthracis were reduced by 26- and 15-fold, depending on whether it was run at 10Hz or 50Hz, respectively. However rather than chemical degradation, deposition on the inner surfaces of the plasma air purifier occured. Our interpretation is that putative “degradation” efficiencies were largely due to electrostatic precipitation rather than to decomposition into smaller molecules.

Mass Balance Method for the SI Value Assignment of the Purity of Organic Compounds

A mass balance method is described for determining the mass fraction of the main component of a high purity organic material. The resulting assigned value is established to be traceable to the SI and can be determined with a small associated measurement uncertainty. Pure organic materials with values and uncertainties determined in this way are necessary as primary calibrators of reference measurement systems in order to underpin the metrological traceability of routine measurement results. The method has been applied to materials in which the main components were respectively theophylline, digoxin, 17β-estradiol, and aldrin. Its performance has been validated in international comparisons coordinated by the BIPM and is in principle applicable to a wide structural range of stable, nonvolatile organic compounds. It has been successfully applied to mass fraction assignments when the main component is present in the range of (950-1000) mg/g and can achieve associated standard uncertainties ranging from 0.5 mg/g (for high purity materials or those containing well-characterized, stable minor components) to 2 mg/g (materials with a significant number or variety of impurities). It is in principle equally applicable to materials with a smaller mass fraction content of the main component.

Liquid Chromatography, Chemical Oxidation, and Online Carbon Isotope Dilution Mass Spectrometry as a Universal Quantification System for Nonvolatile Organic Compounds

A procedure for the universal detection and quantification of polar organic compounds separated by liquid chromatography (LC) based on postcolumn carbon isotope dilution mass spectrometry (IDMS) was developed. The eluent from the LC column is mixed online with a continuous flow of (13)C-enriched sodium bicarbonate, and the sodium persulfate oxidation reaction in acidic media is employed to achieve isotope equilibration. All carbon-containing compounds eluting from the column are oxidized to (12)CO(2) and (13)CO(2), respectively, and the carbon dioxide is separated from the aqueous phase using a gas-permeable membrane. The gaseous carbon dioxide is then carried to the mass spectrometer for isotope ratio measurements. Different water-soluble organic compounds were evaluated using a flow injection configuration to assess the efficiency of the oxidation process. Most water-soluble organic compounds tested showed quantitative oxidation. However, chemical structures involving conjugated C═N double bounds and guanidinium-like structures were found to be resistant to the oxidation and were further studied. For this purpose, (13)C(1)-labeled creatine (with the isotopic label in the guanidinium group) was employed as model compound. Specific conditions for the quantitative oxidation of these compounds required lower flow rates and the addition of metallic catalysts. This novel approach was tested as a universal detection and quantification system for LC. A simple standard mixture of four amino acids was separated under 100% aqueous conditions and quantified without the need for specific standards with good accuracy and precision using potassium hydrogen phthalate as internal standard. The main field of application of the developed method is for the purity assessment of organic standards with direct traceability to the International System of Units (SI).

Identification of Non-Volatile Components and Volatile Organic Compounds in Wet Building Materials

The major volatile components in two solvent-based paints, two thinners, and four adhesives have been identified by a method involving pre-treatment by solvent dilution, filtration, and gas chromatography-mass spectrometry. The non-volatile components in these wet building materials have been determined by infrared spectroscopy. The results have shown the major volatile organic compounds in one-component polyurethane varnish and alkyd paint thinner to be nonane, decane, undecane, xylene, ethylbenzene and ethyltoluene. The main film-forming matter in cement floor paint has been identified as styrenated acrylic emulsion, with the volatile components being mainly butyl acetate, decane and benzene series. The basic substances in these adhesives were polychloroprene, styrene butadiene carboxylated latex, or polyvinyl acetate emulsion. The primary volatile compounds in two adhesives were methyl acetate, and many branched-chain and normal alkanes, while those in the other two adhesives were toluene and benzene.

Non-volatile organic analysis of uranium ore concentrates

In support of nuclear safeguards and non-proliferation efforts, Oak Ridge National Laboratory is responsible for characterizing uranium ore concentrate (UOC) samples obtained from two ore mining and milling sites. A sorptive extraction method has been developed for analysis of non-volatile organic compounds that might be used to identify characteristics of the purification process by which uranium was separated from these ores. This method utilizes Gerstel Twister® stir bars coated with polydimethylsiloxane to extract organic components from aqueous media. A slurry of UOC is extracted with the Twister® stir bar in 20 % methanol/80 % water containing deuterated internal hydrocarbon standards. Following extraction of non-volatile organics, the Twister® stir bar is analyzed directly in the inlet of a gas chromatograph fitted with a quadrupole mass spectrometric detector. Results have been consistent and have shown excellent recoveries of internal standards, with the average recovery being 97.5 %. Both qualitative and quantitative differences have been identified between the two sources of UOC utilizing this method. One source contained an increased concentration of amines which commonly are used in the recovery and purification of ores. Amines that were identified in this UOC source include dioctylamine, triisoctylamine, and Alamine® 336, a common industrial complexant. Also, when comparing both sources, the same UOC source contained various decanol and C20 compounds. Based on the results from this study, non-volatile organic analysis of UOC using sorptive extraction with Twister® stir bars and GC–MS is a tool that can be used to facilitate sourcing of unknown UOC.

Chemical and Biological Combined Treatments for the Removal of Pesticides from Wastewaters

The combination of chemical oxidation (Fenton reaction) and biological treatment processes is a promising technique aiming to reduce recalcitrant wastewater loads. Preliminary tests were carried out on two widely used toxic and non-biodegradable pesticides, namely, Dazomet and Fenamiphos. The chemical reaction was employed as a pre-treatment step for the conversion of the substrates into oxygenated intermediates that were easily removed by means of a final biological treatment. In the combined action, the mineralisation activity of a selected microbial consortium was used to degrade residual volatile and non-volatile organic compounds into CO2 and biomass.

In silico prediction of dermal penetration rate of chemicals from their molecular structural descriptors

The dermal penetration rate of some volatile and non-volatile organic compounds was estimated by quantitative structure–activity relationship approaches by using interpretable molecular descriptors. Linear and nonlinear models were developed using multiple linear regressions (MLR) and artificial neural network (ANN) methods. Robustness and reliability of the constructed MLR and ANN models were evaluated by using the leave-one-out cross-validation method, which produces the statistics of QMLR2=0.786, Q ANN2=0.833 for non-volatiles and QMLR2=0.639, Q ANN2=0.712 for volatile compounds. Furthermore, the chemical applicability domains of these models were determined via leverage approach. The results of this study indicated the ability of developed QSAR models in the prediction of dermal penetration rate of various chemicals from their calculated molecular descriptors.

Prediction of the wash-off of traffic related semi- and non-volatile organic compounds from urban roads under climate change influenced rainfall characteristics

Traffic generated semi- and non-volatile organic compounds (SVOCs and NVOCs) pose a serious threat to human and ecosystem health when washed off into receiving water bodies by stormwater. Climate change influenced rainfall characteristics makes the estimation of these pollutants in stormwater quite complex. The research study discussed in the paper developed a prediction framework for such pollutants under the dynamic influence of climate change on rainfall characteristics. It was established through principal component analysis (PCA) that the intensity and durations of low to moderate rain events induced by climate change mainly affect the wash-off of SVOCs and NVOCs from urban roads. The study outcomes were able to overcome the limitations of stringent laboratory preparation of calibration matrices by extracting uncorrelated underlying factors in the data matrices through systematic application of PCA and factor analysis (FA). Based on the initial findings from PCA and FA, the framework incorporated orthogonal rotatable central composite experimental design to set up calibration matrices and partial least square regression to identify significant variables in predicting the target SVOCs and NVOCs in four particulate fractions ranging from >300 to 1μm and one dissolved fraction of <1μm. For the particulate fractions in >300–1μm range, similar distributions of predicted and observed concentrations of the target compounds from minimum to 75th percentile were achieved. The inter-event coefficient of variations for particulate fractions of >300–1μm was 5–25%. The limited solubility of the target compounds in stormwater restricted the predictive capacity of the proposed method for the dissolved fraction of <1μm.

Optimization of variables on the supercritical fluid extraction of high-boiling organic compounds in house-dust

Epidemiological and clinical studies in the recent years have shown that the importance of the indoor air quality to human health should not be underestimated. The assessment of indoor quality requires efficient and reliable methods producing useful information particularly on that related to indoor dust. A significant task in designing mitigation or prevention measures is to identify firstly the classes of compounds that are present in house dust and secondly obtain their contribution in the samples particularly that of low-volatile or non-volatile organic compounds, for which sparse data is available. Extraction of house dust can be used as a screening method for high boiling organic compounds in the indoor environment. Most published work so far, on organic compounds of low volatility and on particulate organic matter has been focused on a few classes of compounds of known toxicity. However, the absence of knowledge on other possibly present classes of compounds could be crucial in determining the extent of exposure. To override this lack of knowledge, the present study introduces a new method based on supercritical fluid extraction (SFE) to detect the classes of the low-volatile or non-volatile organic compounds that are present in the house-dust samples. The application of the particular method of SFE with CO2 can help to extract and analyze a broad range of low volatile organic compounds in dust of indoor environments, which can lead effectively to a more complete characterization. The particular extraction/analytical method for organics in house dust has been set up consisting of a two step supercritical fluid extraction (SFE) with CO2 and CO2+5% of methanol, collection of the extracts on ODS trap, elution of the extracted compounds with methanol and n-hexane and GC/MS analysis of the eluates.

Towards green membranes: preparation of cellulose acetate ultrafiltration membranes using methyl lactate as a biosolvent

Ultrafiltration membranes were prepared using cellulose acetate (CA) as a polymer, LiCl and CaCl2 as porogens and methyl-(S)-lactate as a solvent. CA, methyl lactate and the porogens used in this work are obtained from renewable resources; they are biodegradable, non-toxic and non-volatile organic compounds. Flat sheet ultrafiltration membranes were prepared by the phase inversion technique. A molecular weight cut-off between 15 and 35 kDa (polyethylene glycol) and pure water permeability between 13 and 177 litres h− 1m− 2 bar− 1 were obtained. These parameters are in the ideal range for water treatment industry. Improvement of pollutant degree and ecotoxicity of the process was evaluated by ‘green’ metrics by the P (pollutants, persistent and bioaccumulative) and E (ecotoxicity) parameters. Both of these variables were recorded as zero using our method. This study represents a step ahead towards the production of ultrafiltration polymeric membranes by a ‘greener’ process than current methods.

Quantitative Techniques for Measuring Cleanroom Wipers with Respect to Airborne Molecular Contamination

Cleanroom wipers are generally of three classifications, namely, synthetic, natural fibers and blends of fibers. Ultra-fine split type fiber is mostly selected as the wiper material since cleanrooms need high filtering efficiency. The three wiper samples selected were made from knitted polyester filament fabric with hot-cut or sealed edges. The wiper samples A and B are considered for the application in Cleanroom Class 10 level environment and wiper sample C is for Cleanroom Class 100 level environment. ASTM E1560-95 and IEST-RP-CC004.3: 2004 are the two standards for testing cleanroom consumables. Following these standards, three specific wipers were compared in terms of residue concentration of liquid particles, ions, metals and non-volatile organic compounds using liquid particle counting (LPC), inductively coupled plasma mass spectrometry (ICP-MS), ion chromatography (IC), and nonvolatile residue (NVR) methods, respectively. All experiments were performed in a cleanroom of Class 100. Detailed test results were very informative to characterize the performance of wipers manufactured by specific processes and materials.

Major components of atmospheric organic aerosol in southern California as determined by hourly measurements of source marker compounds

Abstract. We report the first hourly in-situ measurements of speciated organic aerosol (OA) composition in an urban environment. Field measurements were made in southern California at the University of California–Riverside during the 2005 Study of Organic Aerosol at Riverside (SOAR), which included two separate measurement periods: a summer study (15 July–15 August) and a fall study (31 October–28 November). Hourly measurements of over 300 semivolatile and nonvolatile organic compounds were made using the thermal desorption aerosol gas chromatograph (TAG). Positive matrix factorization (PMF) was performed on a subset of these compounds to identify major components contributing to submicron (i.e., PM1) OA at the site, as measured by an aerosol mass spectrometer (AMS). PMF analysis was performed on an 11-day focus period in each season, representing average seasonal conditions during the summer and a period of urban influence during the fall. As a result of this analysis, we identify multiple types of primary and secondary OA (POA and SOA). Secondary sources contribute substantially to fine OA mass at Riverside, which commonly receives regional air masses that pass through metropolitan Los Angeles during the summer. Four individual summertime SOA components are defined, and when combined, they are estimated to contribute an average 88% of the total fine OA mass during summer afternoons according to PMF results. These sources appear to be mostly from the oxidation of anthropogenic precursor gases, with one SOA component having contributions from oxygenated biogenics. During the fall, three out of four aerosol components that contain SOA are inseparable from covarying primary emissions, and therefore we cannot estimate the fraction of total OA that is secondary in nature during the fall study. Identified primary OA components are attributed to vehicle emissions, food cooking, primary biogenics, and biomass burning aerosol. While a distinction between local and regional vehicle emissions is made, a combination of these two factors accounted for approximately 11% of observed submicron OA during both sampling periods. Food cooking operations contributed ~10% of submicron OA mass during the summer, but was not separable from SOA during the fall due to high covariance of sources. Biomass burning aerosol contributed a larger fraction of fine OA mass during the fall (~11%) than compared to summer (~7%). Primary biogenic aerosol was also identified during the summer, contributing ~1% of the OA, but not during the fall. While the contribution of both local and regional primary vehicle OA accounts for only ~11% of total OA during both seasons, gas-phase vehicle emissions likely create a substantial fraction of the observed SOA as a result of atmospheric processing.

Characterization of Post-Consumer PET after Removal of the Original Surface: Influence of Raw Material

Post-consumer cooking oil and soft drink PET bottles (PEToil and PETsoft drink) were ground and washed only with water (conventional washing). The polymer was then chemically washed (10 min in an aqueous solution of sodium hydroxide 5 mol·L−1 at 90°C) and rinsed. The materials before and after chemical washing were characterized by intrinsic viscosity, differential scanning calorimetry, thermogravimetry, elemental analysis, scanning electron microscopy with X-ray spectrum microanalysis, and gas chromatography coupled to mass spectrometry. The results indicated that conventionally washed PEToil is the material that most differs among the four tested ones, and that the other three are more similar to each other and to what is expected for pure PET. For example, the composition of PEToil washed only in water contained 30 volatile organic compounds, 5 nonvolatile compounds, and 7 metals, while PETsoft drink washed conventionally and chemically contained 5 volatile organic compounds and no metal or nonvolatile organic compounds.

Modeling of ultrasonic degradation of non-volatile organic compounds by Langmuir-type kinetics

Sonochemical degradation of phenol (Ph), 4-isopropylphenol (4-IPP) and Rhodamine B (RhB) in aqueous solutions was investigated for a large range of initial concentrations in order to analyze the reaction kinetics. The initial rates of substrate degradation and H 2O 2 formation as a function of initial concentrations were determined. The obtained results show that the degradation rate increases with increasing initial substrate concentration up to a plateau and that the sonolytic destruction occurs mainly through reactions with hydroxyl radicals in the interfacial region of cavitation bubbles. The rate of H 2O 2 formation decreases with increasing substrate concentration and reaches a minimum, followed by almost constant production rate for higher substrate concentrations. Sonolytic degradation data were analyzed by the models of Okitsu et al. [K. Okitsu, K. Iwasaki, Y. Yobiko, H. Bandow, R. Nishimura, Y. Maeda, Sonochemical degradation of azo dyes in aqueous solution: a new heterogeneous kinetics model taking into account the local concentration OH radicals and azo dyes, Ultrason. Sonochem. 12 (2005) 255–262.] and Seprone et al. [N. Serpone, R. Terzian, H. Hidaka, E. Pelizzetti, Ultrasonic induced dehalogenation and oxidation of 2-, 3-, and 4-chlorophenol in air-equilibrated aqueous media. Similarities with irradiated semiconductor particulates, J. Phys. Chem. 98 (1994) 2634–2640.] developed on the basis of a Langmuir-type mechanism. The five linearized forms of the Okitsu et al.’s equation as well as the non-linear curve fitting analysis method were discussed. Results show that it is not appropriate to use the coefficient of determination of the linear regression method for comparing the best-fitting. Among the five linear expressions of the Okitsu et al.’s kinetic model, form-2 expression very well represent the degradation data for Ph and 4-IPP. Non-linear curve fitting analysis method was found to be the more appropriate method to determine the model parameters. An excellent representation of the experimental results of sonolytic destruction of RhB was obtained using the Serpone et al.’s model. The Serpone et al.’s model gives a worse fit for the sonolytic degradation data of Ph and 4-IPP. These results indicate that Ph and 4-IPP undergo degradation predominantly at the bubble/solution interface, whereas RhB undergoes degradation at both bubble/solution interface and in the bulk solution.

Determination of chlorinated organic compounds in aqueous matrices

Thirteen pure volatile, semi-volatile and non-volatile chlorinated organic compounds of molecular weights ranging from trichloroethylene (MW = 131.39 g mole−1) to hexachlorobenzene (MW = 284.78 g mole−1) were determined in aqueous matrices by GC-ECD. After 10% salt addition, different extraction tests were performed using fibres whose adsorbing phase was based on microsphere carbon particles characterized by a constant size. Five experimental parameters were optimized: extraction temperature and time, position of the fibre in the GC injector port, desorption temperature and time. The optimized analytical protocol was employed to determine the efficiency of a real activated carbon adsorption plant to remove organic chlorinated pollutants from an industrial wastewater at ng l−1 levels.

Novel polyethylene glycol induced cloud point system for extraction and back-extraction of organic compounds

A novel polyethylene glycol (PEG) induced cloud point system (PEG-CPS) with high hydrophile–lipophile balance (HLB) value nonionic surfactant and high molecular weight PEG had been developed for extraction of organic compounds. The main advantage of this novel system is that the back extraction process of stripping of nonvolatile organic compounds from the nonionic surfactant aqueous solution can be carried out with Winsor I microemulsion extraction. Thus a separation of organic compounds from the nonionic surfactants in aqueous solution become possible, which is potential for cloud point extraction (CPE) or extractive microbial transformation in cloud point system from economical and environmental consideration. With Triton X-100 as a model hydrophilic nonionic surfactant, the phase diagram of PEG-CPS was determined. High boiling point organic compounds, such as phenol, p-nitrophenol and 1-naphthol phenol, were extracted with PEG-CPS. Then the organic compounds in the surfactant rich phase of PEG-CPS were back-extracted with microemulsion.

Quick screening method for the photocatalytic activity of nanoparticles and powdery materials

A new quantitative screening method for the photocatalytic activity of nanoparticles and powdery materials was developed. With a custom-built apparatus the measurement of the photodegradation of non-volatile organic compounds in dependence of the inorganic photocatalyst and experimental factors like irradiation time, temperature, organic compound, spectral distribution and irradiance is possible. A new quantitative screening method for the photocatalytic activity of nanoparticles and powdery materials was developed. With a custom-built apparatus the measurement of the photodegradation of non-volatile organic compounds in dependence of the inorganic photocatalyst and experimental factors like irradiation time, temperature, organic compound, spectral distribution and irradiance is possible. By applying various spectral distributions and irradiances slightly lower than in outdoor conditions, the described method uses application-oriented testing conditions. It can be used for the screening of the photocatalytic activity of newly developed materials towards any carbon containing non-volatile compounds.