Gas Chromatography-ion Trap Mass Spectrometry Research Articles

Determination of 101 pesticide residues in Platycodonis radix and extracts of Angelica sinensis by gel permeation chromatography-gas chromatography-ion trap mass spectrometry

With the growing global popularity of traditional medicine and natural drugs， especially in Southeast Asia， the quality of traditional Chinese medicines （TCMs） has attracted the attention of regulators. China's major TCM export destinations， such as South Korea， Japan， and Europe， have formulated strict maximum residue limits （MRLs） of pesticides in TCMs. Therefore， a sensitive and high-throughput method for the simultaneous determination of 101 pesticide residues in Platycodonis radix and extracts of Angelica sinensis was established， involving gel permeation chromatography （GPC） coupled with gas chromatography-ion trap mass spectrometry （GC-ITMS）. In this method， the samples were first ground into fine powder and extracted twice with 20 mL acetonitrile in an ultrasonic cleaner for 30 min. After centrifugation for 10 min at 6000 r/min， the supernatants were combined and dried at 40 ℃ using a rotary vacuum evaporator. The residue was re-dissolved in 2 mL ethyl acetate-cyclohexane （1∶1， v/v） and purified by gel permeation chromatography using a 40 cm×20 mm column. The eluent collecting time was optimized as 17-30 min to ensure both the recovery of target compounds and the removal of interferences such as pigments and lipids from the target compounds. The eluent was then dried and re-dissolved with 1 mL toluene for analysis. The 101 pesticide residues were separated using the DB-5MS capillary column and analyzed by ion trap mass spectrometry. The pretreatment conditions and ion trap mass spectrometry parameters were optimized to effectively reduce the interference of complex TCM matrices and greatly improve the quantitative accuracy of the analysis and recovery of the target pesticides. Three spiked levels of 101 pesticides were tested. The average recovery range was 58.3%-108.9% and the relative standard deviations （RSDs） at the three spiked levels （n=10） ranged from 0.4% to 16.5%. The limits of detection （LODs， S/N=3） of the 101 pesticide compounds ranged from 0.2 to 40.0 μg/kg， while the limits of quantification （LOQs， S/N=10） ranged from 0.6 to 120.0 μg/kg， which met the maximum residue limits of China's main TCM export countries and organizations. This rapid analysis method was easy to operate and high throughput， with strong sensitivity and good repeatability. The employment of gel permeation chromatography overcame the drawback of inadequate cleanup of the solid phase extraction column during TCM analysis. The application of ion trap technology further eliminated the interference of matrix impurities and increased the accuracy of the quantitative and qualitative analyses. This method fills the knowledge gap in multiple pesticide residue determination in TCMs using gas chromatography-ion trap mass spectrometry and is a useful and beneficial alternative to current analytical methods of TCMs.

A validated and optimized method for separation and quantification of total fatty acids by gas chromatography–ion trap mass spectrometry in human plasma

Fatty acids (FAs) are associated with many physiological functions of tissues, and their alteration has been linked with tissue-specific or systemic diseases. The current situation warrants us to have a sensitive and specific method for analysis of total FAs simultaneously from the biological fluid so that the risk prediction, diagnosis or prognosis of the disease can be made effectively. Because of greater sensitivity and resolution, a method of gas chromatography-ion trap mass spectrometry (GC–IT/MS) has been optimized and validated to quantify simultaneously 19 total FAs levels in plasma and compared with GC–triple quadrupole mass spectrometry. FAs have been transesterified by methanolic acetyl chloride to fatty acid methyl esters (FAMEs). A 65 min GC method separated all 19 FAMEs. The calibration curve had good linearity up to 313–922 μM with a correlation coefficient between 0.9882 and 0.9998. The LODs and LOQs of FAMEs were in the range of 0.63 to 9.55 and 2.12 to 31.8 μM, respectively. The method has recovery up to 144 %, stability at 4 °C for 48 h and one freeze–thaw cycle, and good intra-day and inter-day precision. The optimized method has been used to quantify plasma total FAs in type 2 diabetes mellitus patients with and without acute coronary syndrome. Though a significant difference has been found between IT/MS and triple quadrupole mass spectrometry, the GC–IT/MS can help to quantify total FAs in the clinical setting.

A Validated and Optimized Method for Separation and Quantification of Fatty Acids by Gas Chromatography–Ion Trap Mass Spectrometry in Human Plasma

A Validated and Optimized Method for Separation and Quantification of Fatty Acids by Gas Chromatography–Ion Trap Mass Spectrometry in Human Plasma

Fast and Reliable Determination of Phthalic Acid Esters in the Blood of Marine Turtles by Means of Solid Phase Extraction Coupled with Gas Chromatography-Ion Trap/Mass Spectrometry.

The presence of phthalic acid esters (PAEs) in marine environments is an important issue. These chemicals are able to affect marine organisms, particularly marine turtles, and to act as endocrine disrupters. In this paper, for the first time, a simple and reproducible analytical method based on solid-phase extraction (SPE) coupled with gas chromatography—ion trap/mass spectrometry (GC-IT/MS) was developed for the extraction of phthalates from the blood of marine turtles. The extraction was obtained by using C18 phthalates-free as the stationary phase. In order to individuate the best working conditions for the extraction, the adsorption isotherms and breakthrough curves were studied. The overall analytical methodology was validated in terms of limit of detection (LOD, 0.08–0.6 ng mL−1), limit of quantification (LOQ, 0.4–0.8 ng mL−1), and correlation coefficients (>0.9933). By using this procedure, percentage recoveries ranging from 89 to 103% were achieved. The precision parameters (intra-day and inter-day) were studied, and the obtained values were smaller than 12.5%. These data confirm the goodness of the proposed analytical methodology, which is applied to real samples.

Urinary Bisphenol A Concentrations and Parameters of Ovarian Reserve among Women from a Fertility Clinic.

Background: Human exposure to environmentally widespread endocrine disruptors, especially bisphenol A (BPA), has been suggested to affect reproductive health. Animal studies indicate that BPA may play a role in the process of reproduction and impact on maturing oocytes, meiotic cell division or fertilization rate. Nevertheless, data regarding the effects of exposure to BPA on women’s ovarian function are still limited. Therefore, the aim of the current study is to assess the effects of environmental exposure to BPA on ovarian reserve. Methods: The study participants consisted of 511 women in reproductive age (25–39 years) who attended an infertility clinic for diagnosis, due to the couples’ infertility. BPA urinary concentrations were assessed by the validated gas chromatography ion-trap mass spectrometry method. The ovarian reserve was assessed using ovarian reserve parameters: Hormones concentrations: E2 (estradiol), FSH (follicle stimulating hormone), AMH (anti-Müllerian hormone), and AFC (antral follicle count). Results: In the present study, the negative association between BPA urinary concentrations and AMH (p = 0.02) and AFC (p = 0.03) levels was found. Exposure to BPA was not related to other examined parameters of ovarian reserve (FSH, E2). Conclusions: Our results suggest that BPA exposure may affect women ovarian reserve parameters and reduce ovarian reserve. As this is one of the first studies of its kind, the findings need confirmation in a further investigation.

Occurrence of Selected Known or Suspected Endocrine-Disrupting Pesticides in Portuguese Surface Waters Using SPME-GC-IT/MS

A multiresidue analytical methodology based on a solid-phase microextraction (SPME), followed by gas chromatography-ion trap mass spectrometry (GC–IT/MS), has been developed for trace analysis of 20 known or suspected endocrine-disrupting pesticides. The SPME conditions are optimized considering several key parameters to obtain the maximum sensitivity. After the optimization, the method validation is performed, and the limits of detection (ranged from 2–150 ng/L) and the coefficient of determination (above 0.990) of studied compounds are determined for all the analytes. A robust sampling of twenty sampling points of surface water samples from the north and center of Portugal is performed, and the validated methodology is applied. In total, 20 compounds from four chemical families (13 organochlorine, 1 organophosphorus, 2 dicarboximide, and 4 pyrethroids) are studied, and the pesticides most frequently detected are eight organochlorine pesticides (α-, β-HCHs, lindane, HCB, o,p′-DDT, p,p′-DDE, p,p′-DDD, α-endosulfan), cypermethrin, and vinclozolin.

Analysis of six pyrethroid insecticide metabolites in cord serum using a novel gas chromatography-ion trap mass spectrometry method

Pyrethroid insecticides are commonly used for residential and commercial pest control in the US. Pregnant women and their fetuses are vulnerable to pesticide exposures during critical windows of neurodevelopment. Biomonitoring for exposure requires accurate and sensitive methods to assess exposures during pregnancy. The objective of this study was to develop a sensitive analytical method to measure pyrethroid metabolite concentrations in cord serum. Six pyrethroid metabolites, cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropanecarboxylic acid (c/t-DCCA), trans-chrysanthemum dicarboxylic acid (t-CDCA), cis-3-(2,2-dibromovinyl)-2,2-dimethyl-cyclopropane carboxylic acid (c-DBCA), 4-fluoro-3-phenoxybenzoic acid (FPBA), and 3-phenoxybenzoic acid (3PBA) were extracted from cord serum by a dichloromethane liquid-liquid extraction, derivatized by 1,1,1,3,3,3-hexafluoro-2-propanol carboxylic acid esterification, and then measured by gas chromatography/ion trap mass spectrometry. Limits of detection ranged from 0.02 to 0.6 ng/mL. Sixty-three cord serum samples were collected from maternal-fetal dyads in central New Jersey to test for pyrethroid metabolites. Non-specific metabolites, 3PBA, t-DCCA, and t-CDCA, were detected most frequently, present in 29%, 6.3% and 6.3% of samples, respectively. Sensitivities were comparable or greater than other published studies assessing pyrethroid metabolites in cord blood. Comparisons with other literature-reported studies emphasize the importance of method sensitivity when assessing exposures at biologically relevant concentrations.

Clinical utility of validated gas chromatography–ion trap mass spectrometry in patients with anticholinesterase pesticides poisoning

Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in numerous poisoning cases. A simple, accurate, and sensitive gas chromatography-ion trap mass spectrometry-based method for the quantification of 12 anticholinesterase pesticides (monocrotophos, dimethoate, dichlorvos, azinphos-methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, parathion, methidathion, and terbufos) in serum was developed, and its utility in patients with alleged pesticides poisoning was assessed. The quantification was performed using liquid-liquid extraction by toluene/chloroform (4:1,v/v) with 500 μL of serum. On column limit of detection and limit of quantification were less than 50.00 μg/L. The recovery ranged from 97.54 to 103.23%. The calibration curves were linear (R2 > 0.9937). Accuracy was found to be between – 7.1 and 7.2%. Intra-day and inter-day reproducibility was less than 17% for the spiked quality control serum samples. The level of pesticide in serum quantified by the validated method correlated with clinical signs and symptoms, pseudo-cholinesterase activity, total atropine dose, length of hospital stay, and clinical outcome in 15 patients with alleged pesticide poisoning. The validated method may be used for monitoring and prognosis in patients with pesticide poisoning and diagnosis of poisoning in forensic toxicology.

Determination of Non-Steroidal Anti-Inflammatory Drugs in Animal Urine Samples by Ultrasound Vortex-Assisted Dispersive Liquid–Liquid Microextraction and Gas Chromatography Coupled to Ion Trap-Mass Spectrometry

A low solvent consumption method for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) in animal urine samples is studied. The NSAIDs were extracted with CH2Cl2 by the ultrasound vortex assisted dispersive liquid–liquid microextraction (USVA-DLLME) method from urine samples, previously treated with β-glucuronidase/acrylsulfatase. After centrifugation, the bottom phase of the chlorinated solvent was separated from the liquid matrix, dried with Na2SO4, and derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) + trimethylchlorosilane (TMCS) (99 + 1). After cooling at room temperature, the solution was concentrated under nitrogen flow, and 1 µL of solution was analyzed in gas chromatography/ion trap-mass spectrometry (GC-IT-MS). The enrichment factor was about 300–450 times and recoveries ranged from 94.1 to 101.2% with a relative standard deviation (RSD) of ≤4.1%. The USVA-DLLME process efficiency was not influenced by the characteristics of the real urine matrix; therefore, the analytical method characteristics were evaluated in the range 1–100 ng mL−1 (R2 ≥ 0.9950). The limits of detection (LODs) and limits of quantification (LOQs) were between 0.1 and 0.2 ng mL−1 with RSD ≤4.5% and between 4.1 and 4.7 ng mL−1 with RSD ≤3.5%, respectively, whereas inter- and intra-day precision was 3.8% and 4.5%, respectively. The proposed analytical method is reproducible, sensitive, and simple.

Inter-Varietal Diversity of Typical Volatile and Phenolic Profiles of Croatian Extra Virgin Olive Oils as Revealed by GC-IT-MS and UPLC-DAD Analysis.

Despite having an interesting native olive gene pool and a rapidly emerging olive oil industry, monovarietal extra virgin olive oils (EVOO) from Croatia are relatively unexplored. To investigate the inter-varietal diversity of typical volatile and phenolic profiles of Croatian EVOO, 93 samples from six olive (Olea europaea L.) varieties were subjected to gas chromatography-ion trap mass spectrometry (GC-IT-MS) and ultra-performance liquid chromatography with diode array detection (UPLC-DAD), respectively. Quantitative descriptive sensory analysis was also performed. Analysis of variance extracted many relevant exclusive or partial discriminators between monovarietal EVOOs among the identified volatile compounds and phenols. Successful differentiation model with a 100% correct classification was built by linear discriminant analysis, while the most typical volatiles for each monovarietal EVOO were confirmed by partial least squares discriminant analysis. Diverse typical sensory attributes among the EVOOs were tentatively ascribed to the variations in the composition of volatiles and phenols. It was proven that the approach that comprises GC-IT-MS and UPLC-DAD analysis may provide additional objective information about varietal origin and typicity which successfully complement those obtained by sensory analysis. The approach was characterized as universal in nature, with a significant potential to contribute in strengthening the varietal identities and position on the market of monovarietal and Protected Denomination of Origin (PDO) EVOO.

A Method Validation for Simultaneous Determination of Phthalates and Bisphenol A Released from Plastic Water Containers

Phthalates (or phthalate esters, PAEs) and bisphenol A (BPA) are widely used in various industries, particularly in the fields of cosmetics and packaging, and they increase the malleability and workability of materials. As a result of their use, some international health organizations have begun to study them. In this study, the authors developed a methodology for the simultaneous determination of dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DiBP); dibutyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DEHP); di-n-octyl-phthalate (DnOP) and bisphenol A (BPA) from drinking and non-potable waters. The extraction of PAEs and BPA was performed using a solvent-based dispersive liquid–liquid microextraction (SB-DLLME) method. The analytical determination was performed using a gas chromatography–ion trap mass spectrometry (GC-IT/MS) analysis. The entire procedure was validated as recoveries were studied according to the volume and the extraction solvent used, pH, and ionic strength. Dynamic linearity ranges and linear equations of all the compounds were experimentally determined as well as the limit of detection (LOD) (1–8 ng mL−1) and the limit of quantification (LOQ) (5–14 ng mL−1), reproducibility, and sensitivity. The method was applied to 15 water samples (mineral water and tap water) for determining PAEs and BPA released from the plastic container. After the release simulation, four PAEs (i.e., DiBP, DBP, DHEP, and DnOP) were determined at very low concentrations (below 1.2 ng mL−1) in two water samples from (sport) bottles.

Analytical Method Validation for Determining Organophosphorus Pesticides in Baby Foods by a Modified Liquid–Liquid Microextraction Method and Gas Chromatography–Ion Trap/Mass Spectrometry Analysis

Baby food is made specifically for babies between the ages of 4/6 months up to 2 years, and it comes in multiple varieties and tastes. This paper proposes a protocol for a rapid and reliable determination of 19 organophosphorus pesticides (OPs) by means of a method based on ultrasound-vortex-assisted liquid–liquid microextraction coupled with a gas chromatography–ion trap mass spectrometry (UVALLME–GC-IT/MS). The method development starts from the extraction solvent evaluation, i.e., n-heptane; the solution, held for 5 min on the vortex mixer and for 6 min in an ultrasonic bath to 100 W for favoring the solvent dispersion and the determinant extraction, is centrifuged at 4000 rpm for 30 min: 1 μL of the organic extract is injected into the GC-IT/MS. All the analytical parameters investigated are deeply discussed; LODs/LOQs (0.2–1.3 and 0.5–2.9 ng/g) and recoveries (81–109%) are compared with other papers dealing the determination of OPs in baby food matrix. The whole method has been applied to real commercial freeze-dried and soft baby food samples: the results do not show any significant contaminant values.

Formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) from oxidation of 4,4′-dichlorobiphenyl (4,4′-DCB)

This study investigates the formation of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) in oxidation of 4,4′-dichlorobiphenyl (4,4′-DCB) under gas phase conditions over a temperature range of 400–800°C. The experiments involved an isothermal flow reactor equipped with a sample collection system to adsorb PCDD/F. We coated the walls of the reactor, made of high purity quartz, with boric oxide to remove catalytic effects and employed the gas chromatography-ion trap mass spectrometry (GC-ITMS) to quantitate PCDD/F. Trace analysis by GC-ITMS identified all four MCDF and up to five DCDF isomers, of which 3,7-DCDF constitutes the dominant species, formed directly from 4,4′-DCB. MCDD and DCDD appeared at lower concentration, generated from condensation of chlorophenoxy and chlorobenzenes. Our results show significant differences from the measurements of the thermal decomposition of polychlorinated biphenyls (PCB) performed in sealed ampoules, indicating strong surface effects present in earlier studies. Gas-phase reactions (> 600°C) lead to selective formation of a small number of lower-chlorinated pollutants, whereas reactive surfaces, as evident from literature, engender catalytic (but non-selective) appearance of a large number of higher-chlorinated and toxic chloroaryl congeners, even at temperature of less than 300°C. Results from the density functional theory (DFT) calculations indicate that, majority of the detected congeners of PCDF arise from the oxidative transformation of the parent 4,4′-DCB; i.e., not from the commonly suggested precursors of chlorinated phenols and benzenes. Our findings have significant importance to understanding the emission of PCB and PCDD/F in combustion processes.

Plastic pellets, meso- and microplastics on the coastline of Northern Crete: Distribution and organic pollution

Plastic pollution in the marine environment is one of the foremost environmental problems of our time, as it affects wildlife and human health both directly and indirectly through the effects of contaminants carried by microplastics. This study investigates the temporal and spatial distribution of plastic pellets and fragments in sandy beaches along the coastline of Northern Crete, during 2013. Their densities varied throughout the year in each beach, with highest densities during the summer and towards the upper parts of the beaches. The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) sorbed on microplastics sampled from nine sandy beaches of Northern Crete was quantified using Gas chromatography – Ion Trap Mass Spectrometry (GC-ITMS). PAHs concentrations ranged from non-detectable levels to 1592 ng/g and fluctuated between sampling periods. Based on the observed patterns of meso- and microplastics distribution, practical guidelines are proposed to minimize the entrance of microplastics into the seawater wherefrom they are exceptionally difficult to collect, if mitigation actions are to be applied.

Impact of storage time and temperature on volatomic signature of Tinta Negra wines by LLME/GC-ITMS

The current study reports the effect of storage temperature, storage time and glucose content on the volatomic signature of Tinta Negra wines using liquid-liquid microextraction (LLME) combined with gas chromatography–ion trap mass spectrometry (GC–ITMS). A total of 65 volatile organic compounds (VOCs) were identified in Tinta Negra, of which only 14 appear during storage. Based on the results, the freshness and fruitiness odours that are related to the presence of some varietal and fermentative components (e.g. terpenic compounds, esters) are lost during wine storage, while other descriptors such as caramel, dried fruit, spice, toast and wood arise due to Maillard reactions (e.g. furanic compounds), among other chemical reactions (e.g. lactones). The results obtained in this study may be applied as a useful tool in the winemaking field in order to introduce changes in the baking (estufagem) process and/or predict the effects of storage time when applying high temperatures. In addition, the VOCs identified in this study may help winemakers and wine chemists better understand the aroma composition and profile of Tinta Negra wines.

Simultaneous determination of free methamphetamine, pethidine, ketamine and tramadol in urine by dispersive liquid–liquid microextraction combined with GC–MS

ABSTRACTA simple and rapid dispersive liquid–liquid microextraction (DLLME) technique coupled with gas chromatography–ion trap mass spectrometry (GC–MS) was developed for the extraction and analysis of methamphetamine (MA), pethidine (PD), ketamine (KT) and tramadol (TD) from human urine. In this study, different parameters affecting the extraction process such as the type and volume of extraction solvent, type and volume of disperser solvent, extraction time and pH value and salt effect were studied and optimized. Under optimized conditions, the enrichment factor ranged from 185 to 226 and the average recovery ranged from 80.45% to 95.55%. The linear range was 10.0–1000.0 µg/L, the limit of detection and quantitation were in the range 0.43–1.96 µg/L and 1.44–6.53 µg/L, respectively. The relative standard deviations were in the range 1.98%–3.90% (n = 7). The obtained results show that DLLME combined with GC–MS is a fast and simple method for the determination of MA, PD, KT and TD in human urine.

Volatile composition of Merlot red wine and its contribution to the aroma: optimization and validation of analytical method

A methodology for the determination of volatile compounds in red wine using headspace solid phase microextraction (HS-SPME) combined with gas chromatography-ion trap/ mass spectrometry (GC-IT/MS) and flame ionization detector (GC -FID) was developed, validated and applied to a sample of Brazilian red wine. The optimization strategy was conducted using the Plackett-Burman design for variable selection and central composite rotational design (CCRD). The response surface methodology showed that the performance of the extraction of the volatile compounds using divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber is improved with no sample dilution, the addition of 30% NaCl, applying an extraction temperature of 56°C and extraction time of 55min. The qualitative method allowed the extraction and identification of 60 volatile compounds in the sample studied, notably the classes of esters, alcohols, and fatty acids. Furthermore, the method was successfully validated for the quantification of 55 volatile compounds of importance in wines and applied to twelve samples of Merlot red wine from South of Brazil. The calculation of the odor activity value (OAV) showed the most important components of the samples aroma. Ethyl isovalerate, ethyl hexanoate, 1-hexanol, octanoic acid and ethyl cinnamate had the greatest contribution to the aroma of the wines analyzed, which is predominantly fruity with the presence of herbal and fatty odors.

Determination of five endosulfan pesticides in the fish pond water by dispersive liquid–liquid microextraction combined with GC–MS

ABSTRACTA simple and rapid dispersive liquid–liquid microextraction (DLLME) technique coupled with gas chromatography–ion trap mass spectrometry (GC–MS) was developed for the extraction and analysis of five endosulfan pesticides from the fish pond water. In this work, different parameters affecting the extraction process such as the type and volume of extraction solvent, type and volume of disperser solvent, and extraction time were studied and optimized. Under optimized conditions, the enrichment factor ranged from 189 to 269 and the relative recovery ranged from 88.5% to 94.9%. The linear range was 2.0–80.0 µg/L; the limits of detection and quantitation were in the range 0.04–1.06 µg/L and 0.12–3.53 µg/L, respectively. The relative standard deviations were in the range 0.94%–2.08% (n = 5). The obtained results show that DLLME combined with GC–MS is a fast and simple method for the determination of endosulfan pesticides in fish pond water.

Changes in volatile compounds of Dittrichia viscosa caused by the attack of the gall-forming dipteran Myopites stylatus

The false yellowhead Dittrichia viscosa (L.) Aiton (Asteraceae) is a spontaneous plant occurring in southern Europe. A tritrophic relationship is observed in the aerial parts of this plant since flowers are attacked by the gall-forming dipteran Myopites stylatus (Fabricius) which, in turn, is parasitized by hymenopteran species. This relationship may be mediated by volatile organic compounds (VOCs) released by the aerial parts of the plant. Thus, VOCs exhaled by leaves, flowers and flower galls of D. viscosa were characterized by headspace solid-phase microextraction (HS-SPME) and gas chromatography-ion trap-mass spectrometry (GC-IT-MS). A total of 46 compounds were identified, including alcohols, aldehydes, esters, ketones, phenol derivatives, terpenes and sesquiterpenes. Volatile fractions registered from the different aerial parts of D. viscosa were quantitative and qualitatively different. Leaves were composed by 31 volatile compounds, flowers by 34 and galls by 29. Sesquiterpenes represented about 76.8% of the volatiles exhaled from leaves; flowers were composed mainly by sesquiterpenes (49.1%) and terpenes (34.6%) such as α-pinene, limonene and β-pinene and flower galls exhaled phenol derivatives (68.7%) such as anethol and estragole, and terpenes (25.1%) such as eucalyptol and limonene. Several sesquiterpene like compounds were exclusive from leaves, while esters (e.g. methyl-2-propylhexanoate) were exclusive from flowers and the terpene eucalyptol from flower galls. The potential effect of volatiles exhaled by the different aerial parts of D. viscosa on the behaviour of insects implicated in the relationship with D. viscosa is discussed.

Influence of packaging and aging on the red wine volatile composition and sensory attributes

Abstract This work studied the volatile composition and sensory properties of red wines after packaging under different configurations: bag-in-box (BIB) and glass bottles sealed with natural cork stoppers. The experiments were carried out over a period of 12 months and analysis were performed at initial time (just before packaging) and after 3, 6 and 12 months of storage. Volatile compounds composition was determined by two different analytical techniques which combined headspace solid-phase microextraction (HS-SPME) with gas chromatography-ion trap/mass spectrometry (GC-IT/MS). Sensory analysis and other enological parameters, such as free and total SO 2 and color intensity, were also monitored. Results showed that, after one year of storage, BIB wines were characterized by higher levels of several carbonyl compounds when compared to bottled wines. Moreover, bottled wines sealed with cork stoppers ​retained much more free and total SO 2 than wines in BIB. In addition, the premature wine development under BIB was confirmed by sensory analyses.