Concentrations Of 2-propanol Research Articles

Influence of Saccharomyces cerevisiae strain on the profile of volatile organic compounds of blossom honey mead

The influence of yeast strain on the volatile profile of meads fermented from blossom honey using three different Saccharomyces cerevisiae var. bayanus strains was evaluated. Meads were analysed by methods of basic chemical analysis and gas chromatography after 15 days of fermentation. Individual yeast strains produced various metabolites in different concentrations under the same fermentation conditions which significantly influenced the final secondary aroma of mead. Higher concentrations of acetaldehyde and 1-propanol, associated with S. cerevisiae var. bayanus MM-R2 considerably distinguished this strain from the others, whereas the difference between strains S. cerevisiae var. bayanus FM-R-Fix1 and MT-R1B was characterised by the production of ethyl hexanoate, ethyl octanoate (FM-R-Fix1), and isobutyl alcohol (MT-R1B).

High concentration of propanol does not significantly alter the triple helical structure of type I collagen

The effect of isopropyl alcohol (IPA) and n-propyl alcohol (PA) on collagen, the main component of the various connective tissues in animals, was analyzed to explore the solvent-induced polarity stress. Collagen precipitates in the presence of IPA and PA at concentrations (>50 %, v/v). The properties of precipitated collagen, after re-dissolving them in acetic acid solution, was investigated to understand (i) whether collagen precipitates induced by IPA and PA is in native or denatured form and (ii) the role of alkyl chain (linear and branched) in the solvent on the precipitation of collagen. Results demonstrate that precipitated collagen in both PA and IPA not only retains its triple helical structure but also maintains its thermal stability, fibrillation, and fluorescence properties as that of native collagen. The results also demonstrate that the nature of alkyl chain in the solvent has minor influence on the structural characteristics of collagen during precipitation.

Effect of 2-Propanol on the Transfer Hydrogenation of Aldehydes by Aqueous Sodium Formate using a Rhodium(I)-sulfonated Triphenylphosphine Catalyst

In water/2-propanol mixtures [RhCl(mtppms)(3)] (mtppms = monosulfonated triphenylphosphine) was an efficient catalyst for the selective C=C reduction of trans-3-phenyl-2-propenal (trans-cinnamaldehyde) by hydrogen transfer from formate at temperatures as low as 30 °C. An outstandingly high catalyst turnover frequency of 1214 h(-1) was determined at 70 °C. A possible mechanism of the reaction is suggested on the basis of kinetic studies and (1)H- and (31)P-NMR spectroscopic identification of the major Rh(I) species in the reaction mixtures as cis-mer-[H(2)RhX(mtppms)(3)] (X = HCOO(-) or H(2)O). It was established that a large part but not all of the rate increase observed in water/2-propanol mixtures in comparison with systems with neat water as solvent was the consequence of complete dissolution of trans-cinnamaldehyde on the effect of the co-solvent. Nevertheless, the rate showed a significant further increase with increasing 2-propanol concentration even in homogeneous solution and this was ascribed to changes in the solvent structure. The high catalyst activity in this solvent mixture allowed the transfer hydrogenation of citral. Although good to excellent conversions were observed at 30-70 °C, a useful degree of selectivity in hydrogenation of C=C vs. C=O bonds could not be achieved.

Relaxation oscillations of solutal Marangoni convection at curved interfaces

Relaxation oscillations in a two-phase system, consisting of paraffin oil and water, with 2-propanol initially dissolved in the oil phase, are observed as a periodic decay and re-amplification of interfacial convection. Due to the mass transfer of the weakly surface-active 2-propanol, concentration gradients and, by implication, density gradients exist. This leads to a periodic coupling of Marangoni instability, buoyant convection and the restoring effects of diffusion. The relaxation oscillations are facilitated by the presence of interfacial curvature, which imposes additional gradients of interfacial tension. This effect is particularly pronounced around drops or bubbles formed in the experiments. The markedly regular relaxation oscillations appearing in that case have been further studied by 2D Hele-Shaw simulations based on a diffuse-interface model. Interfacial tension is assumed to depend linearly on 2-propanol concentration without accumulation of matter at the interface. This simplified approach is capable of reproducing the relaxation oscillations observed experimentally.

Separation and Determination of Phenylpropanoid Glycosides in Rhodiola by Microemulsion Electrokinetic Chromatography

A novel microemulsion electrokinetic chromatography (MEEKC) method for the simultaneous separation and quantitative determination of phenylpropanoid glycosides in Rhodiola L. was developed. The effects of many parameters influencing separation characteristics were optimized. Retention factor met rosarin<rosavin<rosin at the same 2-propanol concentration. Both selectivity and resolution of rosarin and rosavin increased with increasing 2-propanol content. The similar chemical structure led to a small difference in theoretical plates. The resolution of rosarin and rosavin showed greater improvements than rosavin and rosin with increasing buffer pH. According to the separation characteristics, the optimal running buffer was determined: 80 mmol/L sodium dodecyl sulfate, 1.0% n-heptane, 7.5% 1-buatnol, 22.5% 2-propanol, and 10 mmol/L sodium borate buffer at pH 9.25. Validation showed that this simple MEEKC method possesses feasible accuracy and precision. Furthermore, the developed method successfully quantified three phenylpropanoid glucosides in the Rhodiola rosea sample extracts and three oral liquids.

Wettability of polytetrafluoroethylene and polymethyl methacrylate by aqueous solutions of TX-100 and TX-165 mixture with propanol

The measurements of the contact angle of the aqueous solutions of TX-100 and TX-165 mixture with propanol on polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) were carried out. On the basis of the obtained results, the dependence between the cosine of contact angle and surface tension as well as between the adhesion and surface tension of the solutions in the light of the work of adhesion of the solutions to the PTFE and PMMA surface was discussed. The dependence between the adhesion and surface tension for PMMA was correlated to the surface concentration of propanol as well as TX-100 and TX-165 mixture concentration determined from the Frumkin equation at the PMMA-air, PMMA-solution and solution–air interfaces. For this purpose, the surface tension of PMMA covered by a surface active agent film was determined using the Neumann et al. equation and next the PMMA–solution interface tension was evaluated from the Young equation. The values of the surface tension of PMMA covered by propanol and surfactants mixture layer were applied to describe the changes of the adhesion work of solutions to PMMA surface as a function of propanol and surfactants mixture concentration. The adhesion work of the aqueous solutions of TX-100 and TX-165 mixture with propanol to the PTFE and PMMA surfaces was discussed in the light of the adhesion work of particular components of the solutions. On the basis of the results obtained from the contact angle measurements, the standard Gibbs free energy of adsorption of particular components of solution was also considered.

Classification and Quantification of Binary Mixtures of Gases/Odors Using Thick-Film Gas Sensor Array Responses

This paper presents the results of experiments done for classification and quantification of two volatile organic compounds (VOCs), namely, acetone (CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> COCH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) and 2-Propanol (CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> CHOHCH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ) in their single as well as in mixture forms. A sensor array consisting of four sensor elements was fabricated in our lab using thick-film fabrication technology. The steady-state responses of the sensor array were collected for the mentioned VOCs in their single as well as in mixture form. A hierarchical system consisting of gating network and three quantification networks was designed to classify and subsequently quantify the individual and mixture of VOCs. The classification accuracy results of gating network have been ensured using back-propagation neural network (BPNN) and support vector machine (SVM). For quantification multioutput support vector regression method was used in slave networks for single as well as binary mixture data. k-fold cross validation scheme was adopted for all the experiments. The average classification accuracy of gating network for the mixture data in raw form was 89.5% using BPNN and 94.7% using nu-SVM. With principal component analysis preprocessed data, the average accuracy was 95.6% with BPNN and 100% using nu-SVM, respectively. For quantification, good 0.9828 and 0.9764 correlation coefficients for the predicted versus real concentration of acetone and 2-Propanol, respectively, in mixture form were obtained. Thus, we report a promising approach for binary mixture of gases/odors analysis using thick-film gas sensor array responses.

Volumetric properties of sodium dodecylsulfate and Triton X-100 mixture with short-chain alcohol in aqueous solution

Measurements of the surface tension, density, dynamic viscosity and specific conductivity of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl)phenoxypoly(ethylene glycol) (Triton X-100 or TX-100) and sodium dodecylsulfate (SDDS) mixture with a short-chain alcohol (methanol, ethanol or propanol) were carried out. The obtained results indicate that surfactants can aggregate in the presence of alcohol and vice versa. The concentration at which alcohol starts to form aggregates (CAC) depends only slightly on the surfactant mixture composition and concentration and it is close to that obtained for the aqueous solutions of a given alcohol. On the other hand, surfactant mixture can form micelles only in the range of alcohol concentration in which it is present in the monomeric form in the bulk phase. At very low concentration of ethanol and propanol, the CMC decrease of the surfactant mixture takes place. The obtained results indicate also that the apparent and partial molar volumes of water practically do not depend on the composition and concentration of the surfactant mixture and they are similar to those obtained in the aqueous solution of alcohol. However, the volumetric properties of alcohols depend somewhat on the composition and concentration of the surfactant mixture. Similarly to the aqueous solution of a single alcohol, the apparent molar volume isotherm of methanol in the studied solutions does not have any extremum contrary to ethanol and propanol. The apparent molar volumes of the surfactant mixture in the micellar state are higher than in the monomeric form. The composition of the mixed micelles reflects the tendency of TX-100 and SDDS to the micelle formation in their aqueous solutions in the presence of alcohol.

Separation, Concentration and Determination of Trace Thiamphenicol in Egg, Milk and Honey Using Polyoxyethylene Lauryl Ether-Salt Aqueous Two-Phase System Coupled with High Performance Liquid Chromatography

As a pretreatment technique to trace analysis, polyoxyethylene lauryl ether (POELE10)- salt aqueous two-phase extraction system (ATPES) is coupled with high performance liquid chromatography to analyse thiamphenicol (TAP) in egg, milk and honey. The analysis of the phase behaviors of the ATPES found that the extraction efficiency and enrichment factor of TAP was influenced by the types of salts, the concentration of salt, the concentration of POELE10, the concentration of 1-propanol and the temperature. The optimized conditions of experiment were determined in the multi-factor experiment by using response surface methodology. The extraction efficiency of TAP is up to 99.59% and the optimal values of enrichment factor of TAP was 27 under the optimized conditions. The limit of detection and the limit of quantification of TAP are 0.5 µg kg−1 and 1.5 µg kg−1, which meet the needs of determination of trace or ultratrace TAP in food.

Impact of blood collection tubes on erroneous 1-propanol detection and on forensic ethanol analysis

Impact of blood collection tubes on erroneous 1-propanol detection and on forensic ethanol analysis Aim: The present study aims to emphasize the importance of selecting the proper blood collection tubes for the right intended use in order to avoid erroneous results, especially in reference to forensic alcohol analysis. Introduction: Forensic alcohol analysis in blood from living subjects is performed in various situations, such as driving under the influence, is usually related to consumption of alcoholic beverages and often results to the detection of ethanol and/or congener alcohols. Alternatively, ethanol and congeners, such as 1-propanol, can be microbially produced especially in autopsy samples. Methods: Sixty eight blood samples from living subjects, all drivers involved in traffic accidents, contained in different collection tubes, were included in the study. Volatiles were detected with a validated HS-GC-FID method. Samples of normal human blood, spiked with ethanol and/or 1-propanol, dispersed in different tubes were treated and analyzed as the authentic blood samples in order to test the suitability of the collection tubes. Results: Authentic blood samples, contained in certain tubes with separator gel, had high concentrations of “1-propanol”. It was shown that the separator gel released a substance that was recognized as “1-propanol” during analysis by HS-GC-FID at 600C (routine conditions). The erroneous “1-propanol” was separated from authentic 1-propanol during analysis at 580C. Discussion: The separator gel of certain blood collection tubes compromises a source of pre-analytical error that results to erroneous concentrations of 1-propanol. This is unfavorable in forensic cases and can complicate interpretation of the origin (exogenous or microbial) of the detected ethanol.

가수량 변화가 개량누룩으로 발효한 증류식 소주용 술덧의 특성에 미치는 영향

This study was conducted to investigate the effects of varying the amount of water added on the characteristics of mash fermented using modified Nuruk for distilled-Soju production. As the amount of water added to the mash increased from 120 to 300%, the pH dropped from 4.6 to 4.2, resulting in reductions in the acidity from 6.0 to 5.2, in the amino acid level from 6.0 to 4.2, and in the soluble-solid content from 18.4 to 7.4 °Brix. The alcohol concentration of the mash was highest at 17.6%, when 150% water was added, while the alcohol yield showed water-content-dependent increases of 59.7, 74.5, 80.8, 82.8, 89.4, and 90.6% with 120, 150, 180, 200, 250, and 300% water added, respectively. The values of the organic-acid content in the mash were 207.85, 222.38, 222.06, 204.56, 194.34, and 204.34 mg/100 mL, showing the highest values when 150 and 180% water was added. The total amino-acid content showed water-content-dependent decreases at 474.60, 317.32, 241.89, 244.51, 189.00, and 208.12 mg/100 mL, with arginine, alanine, glutamic acid, glycine, isoleucine, leucine, lysine, phenylalanine, proline, serine, tyrosine, and valine as the major components. The concentrations of isobutanol, isoamyl alcohol, 1-propanol, and 2-phenylalcohol were 154.88~182.62, 320.59~394.47, 91.50~170.91, and 108.93~144.26 ppm, respectively, while ethyl acetate, acetaldehyde, furfural, and butyric acid were also detected.

Mutual influence of two nonionic surfactants mixture and propanol on their volumetric properties in aqueous solution

The mutual influence of propanol and two nonionic surfactant mixtures Triton X-100 (TX-100) and Triton X-165 (TX-165) on their behavior in aqueous solution was studied by the measurements of the surface tension, density and viscosity. The obtained results were used for the determination of both critical micelle concentration and propanol critical concentration of aggregation (CAC). It appeared that CAC only slightly depends on the surfactant mixture concentration, but CMC increases considerably at the propanol concentration close to CAC. However, over this concentration micelle formation of surfactant mixture was not observed. The values of CMC of surfactant mixture at a given propanol concentration were slightly lower than those determined in the aqueous solutions of TX-100 with propanol and TX-165 with propanol. The determined values of CAC and CMC were used for the standard Gibbs free energy of the propanol aggregation and surfactant mixture micellization calculation.

The effect of glycerol and 2-propanol on the molecular aggregation of collagen in solution

The molecular aggregation of collagen solution (Col) in the presence of glycerol (Col-G) and 2-propanol (Col-P) was investigated. The transition temperature (Tm) of collagen, determined by ultra-sensitive differential scanning calorimetry, increased proportionally to the concentration of glycerol about 0.929°C per 1M, while Tm decreased proportionally to the concentration of 2-propanol about 1.638°C per 1M. The fluorescence spectra of collagen in solutions were detected by two-dimensional technique on the perturbation of the concentration of glycerol and 2-propanol and showed different results in Col-G and Col-P. The size of collagen aggregates in solutions was observed by dynamic light scattering. Compared with the aggregate size in Col, collagen aggregates became smaller in the presence of glycerol, whereas it grew larger in the presence of 2-propanol. Furthermore, the different extent of aggregation in Col, Col-G and Col-P influenced the self-assembly of collagen molecules under physiological conditions, and there were differences in the resulted fibril structures of Col, Col-G and Col-P after fibrillogenesis as determined by scanning electron microscopy. These results indicated that glycerol inhibited the collagen aggregates while 2-propanol promoted them in solution.

Potassium sorbate reduces production of ethanol and 2 esters in corn silage

The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor air quality and reduce feed intake. Silage additives may reduce VOC production in silage by inhibiting the activity of bacteria or yeasts that produce them. We produced corn silage in 18.9-L bucket silos using the following treatments: (1) control (distilled water); (2) Lactobacillus buchneri 40788, with 400,000cfu/g of wet forage; (3) Lactobacillus plantarum MTD1, with 100,000cfu/g; (4) a commercial buffered propionic acid-based preservative (68% propionic acid, containing ammonium and sodium propionate and acetic, benzoic, and sorbic acids) at a concentration of 1g/kg of wet forage (0.1%); (5) a low dose of potassium sorbate at a concentration of 91mg/kg of wet forage (0.0091%); (6) a high dose of potassium sorbate at a concentration of 1g/kg of wet forage (0.1%); and (7) a mixture of L. plantarum MTD1 (100,000cfu/g) and a low dose of potassium sorbate (91mg/kg). Volatile organic compound concentrations within silage were measured after ensiling and sample storage using a headspace gas chromatography method. The high dose of potassium sorbate was the only treatment that inhibited the production of multiple VOC. Compared with the control response, it reduced ethanol by 58%, ethyl acetate by 46%, and methyl acetate by 24%, but did not clearly affect production of methanol or 1-propanol. The effect of this additive on ethanol production was consistent with results from a small number of earlier studies. A low dose of this additive does not appear to be effective. Although it did reduce methanol production by 24%, it increased ethanol production by more than 2-fold and did not reduce the ethyl acetate concentration. All other treatments increased ethanol production at least 2-fold relative to the control, and L. buchneri addition also increased the 1-propanol concentration to approximately 1% of dry matter. No effects of any treatments on fiber fractions or protein were observed. However, L. buchneri addition resulted in slightly more ammonia compared with the control. If these results hold under different conditions, a high dose of potassium sorbate will be an effective treatment for reducing VOC production in and emission from silage. Regulations aimed at reducing VOC emission could be ineffective or even increase emission if they promote silage additives without recognition of different types of additives.

Experimental study of the density and derived partial molar volumes of complex ternary water + 1-propanol + Li2SO4 mixtures at temperatures from (303 to 448) K and pressures up to 40 MPa

Densities of complex ternary water+1-propanol+Li2SO4 mixtures have been measured over the temperature range from (303 to 448)K and at pressures up to 40MPa using the constant-volume piezometer immersed in a precision liquid thermostat. The measurements were performed for nine samples with concentrations of Li2SO4 from (0.00623 to 0.0274) mole fraction and concentrations of 1-propanol from (0.01553 to 0.05024) mole fraction. In this work the mole fraction of 1-propanol is given in the electrolyte (Li2SO4)-free solution. The combined expanded uncertainty of the density, pressure, temperature, and concentration measurements at the 95% confidence level with a coverage factor of k=2 is estimated to be 0.06%, 0.05%, 20mK, and 0.015%, respectively. Measured values of density for ternary mixtures were used to calculate partial molar volumes of alcohol (1-propanol), (V¯1), and salt (Li2SO4), (V¯2). The temperature and pressure dependences of the partial molar volumes were studied. The concentration dependences of the partial molar volumes were extrapolated to zero concentration (x1→0 in alcohol dilute mixture and x2→0 salt dilute mixture) to yield the partial molar volumes of alcohol (V¯10) and salt (V¯20) at infinite dilutions.

Influence of the propanol on the behaviour of binary mixture of nonionic surfactants at the water–air interface

The influence of propanol on the behaviour of mixed nonionic/nonionic surfactant solutions, that is p-(1,1,3,3-tetramethylbutyl)phenoxypoly(ethylene glycols) Triton X-100 (TX-100) and Triton X-165 (TX-165) at the water–air interface was studied by measuring the surface tension. The obtained results of the surface tension measurements were compared with those calculated from the von Szyszkowski and Connors equations. It appeared that using the Connors equation, it is possible to describe the dependence between the surface tension of studied solutions as a function of propanol concentration. However, in the case of the Szyszkowski equation it was possible to describe this dependence with good accuracy only in the range of propanol concentration from 0 to that corresponding to the propanol molecules aggregation (CAC). The constant b in the Szyszkowski equation is equal to that in the Langmuir one and allows calculating the values of the standard Gibbs free energy of propanol adsorption which is nearly the same as those determined from the Gu and Zhu equation. The standard Gibbs free energy of adsorption of propanol and surfactant mixture indicates that propanol decreases the surfactant mixture adsorption to a larger extent than vice versa which is confirmed by the comparison of the surface layer composition. At the concentration of propanol higher than its CAC, the surface tension of the solution in the presence and absence of surfactants mixture is the same which suggests that the adsorption of surfactants is very small or practically close to zero.

Characterization of metabolites determined by means of 1H HR MAS NMR in intervertebral disc degeneration.

ObjectThe objective of this study is the identification of metabolites by means of 1H high resolution magic angle spinning nuclear magnetic resonance (1H HR MAS NMR) spectroscopy and the evaluation of their applicability in distinguishing between healthy and degenerated disc tissues. Materials and methodsDifferences between the metabolic profiles of healthy and degenerated disc tissues were studied by means of 1H HR MAS NMR. Analysis was performed for 81 disc tissue samples (control samples n = 21, degenerated disc tissue samples n = 60). Twenty six metabolites (amino acids, carbohydrates, and alcohols) were identified and quantified.ResultsThe results indicate that the metabolic profile of degenerated discs is characterized by the presence of 2-propanol and the absence of scyllo-inositol and taurine. The concentrations of 2-propanol and lactate increase with age.ConclusionPCA analysis of ex vivo 1H HR MAS NMR data revealed the occurrence of two groups: healthy and degenerative disc tissues. The effects of insufficient nutrient supply of discs, leading to their degeneration and back pain, are discussed.Electronic supplementary materialThe online version of this article (doi:10.1007/s10334-014-0457-0) contains supplementary material, which is available to authorized users.

Enhancement and inhibition effects of water matrices during the sonochemical degradation of the antibiotic dicloxacillin

The sonochemical degradation of dicloxacillin (DXC) was studied in both synthetic and natural waters. Degradation routes and the effect of experimental conditions such as pH, initial DXC concentration and ultrasonic power were evaluated. Experiments were carried out with a fixed frequency (600kHz). The best performances were achieved using acidic media (pH=3) and high power (60W). The degradation process showed pseudo-first order kinetics as described by the Okitsu model. To evaluate water matrix effects, substrate degradation, in the presence of Fe2+ and organic compounds such as glucose and 2-propanol, was studied. A significant improvement was achieved with Fe2+ (1.0mM). Inhibition of the degradation process was observed at a relatively high concentration of 2-propanol (4.9mM), while glucose did not show any effect. Natural water showed an interesting effect: for a low concentration of DXC (6.4μM), an improvement in the degradation process was observed, while at a higher concentration of DXC (0.43mM), degradation was inhibited. Additionally, the extent of degradation of the process was evaluated through the analysis of chemical oxygen demand (COD), antimicrobial activity, total organic carbon (TOC) and biochemical oxygen demand (BOD5). A 30% removal of COD was achieved after the treatment and no change in the TOC was observed. Antimicrobial activity was eliminated after 360min of ultrasonic treatment. After 480min of treatment, a biodegradable solution was obtained.

Analysis of human breath samples of lung cancer patients and healthy controls with solid-phase microextraction (SPME) and flow-modulated comprehensive two-dimensional gas chromatography (GC × GC)

This paper reports the use of chromatographic profiles of breath volatiles to determine disease markers in lung cancer patients and healthy volunteers. The volatile fraction was isolated by headspace solid-phase microextraction (HS-SPME) and analyzed by flow-modulated comprehensive two-dimensional gas chromatography and flame ionization (GC × GC-FID). Following the experiments, collected data were transformed, and partial least-squares discriminant analysis (PLS-DA) as well as Mann–Whitney Test were carried out to model the data and discover breath metabolites with a significant concentration difference between patients and healthy subjects. Using the abovementioned method, lung cancer patients and healthy controls could be correctly distinguished based on metabolic VOCs abnormality in human breath. Five potential target compounds including acetone, isoprene, methanol, pentane and propanol were identified. Lung cancer patients show higher concentrations of propanol (7415.3 ng L−1), acetone (1811.6 ng L−1) and methanol (225 ng L−1) compared with those of healthy volunteers (1975.3 ng L−1, 579.9 ng L−1, 76.8 ng L−1, respectively). In addition, there is no significant relationship between breath VOCs and gender or body mass index (BMI). This approach will facilitate the comparison of complex breath VOC profiles and diseases. These findings may offer valuable and reliable information for the early diagnosis and prognosis of lung cancer.

Determination of volatile organic compounds as potential markers of lung cancer by gas chromatography–mass spectrometry versus trained dogs

The main aim of the study was qualitative and quantitative analysis of volatile organic compounds (VOCs) occurring in biological samples such as exhaled air obtained from 108 patients with lung cancer, 121 healthy volunteers, and 24 persons with other lung diseases. For determination of VOCs in human breath, solid phase microextraction and gas chromatography–mass spectrometry (SPME/GC–MS) were applied. Statistical methods such as artificial neural network and chi-squared automatic interaction detector (CHAID) were applied for data evaluation. The concentration of acetone, isoprene, ethanol, 1-propanol, 2-propanol, hexanal, and dimethyl sulfide were higher in patients with lung cancer than in case of healthy volunteers and persons with other lung diseases.The second goal was the application of trained dogs for detection of the same breath samples as in GC–MS research and evaluate the sensitivity and specificity of canine scent detection using 5 station scent lineup. Among lung cancer patients and complementary samples, overall sensitivity of canine scent detection was 86%, while specificity was 72%.There is a possibility that in the future these methods could allow for a fast, painless, and noninvasive diagnosis of cancer.