The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Daniel B Cardin - One of the best experts on this subject based on the ideXlab platform.
-
vacuum assisted sorbent Extraction an analytical methodology for the determination of ultraviolet filters in environmental samples
Talanta, 2020Co-Authors: Maria J Trujillorodriguez, Jared L Anderson, Sage J B Dunham, Victoria L Noad, Daniel B CardinAbstract:Abstract Vacuum-assisted sorbent Extraction (VASE) has been applied in combination with gas chromatography-mass spectrometry for the determination of UV filters in water samples. VASE is a variant of Headspace Extraction which was developed in conjunction with the sorbent pen (SP) technology. This technique combines the advantages of both stir-bar assisted Extraction and Headspace solid-phase microExtraction. The SP traps allowed both reduced pressure in-vial Extraction and direct thermal desorption via a unique gas chromatographic injection port. The main parameters that affect the performance of VASE, including both Extraction and desorption conditions, were extensively optimized. Under optimum conditions, Extraction required 10 mL of sample within 40 mL vials, pH 3.5, ~30 s of air-evacuation, 14 h incubation at 70 °C, stirring at 200 rpm, and a final water management step conducted at ~ −17 °C for 15 min. Optimal thermal desorption required preheating at 260 °C for 2 min followed by desorption at 300 °C for 2 min. The beneficial effect of reduced-pressure Extraction was demonstrated by comparing the UV filter Extraction time profiles collected using VASE to an analogous atmospheric pressure procedure, resulting in up to a 3-fold improvement under optimized conditions. The VASE methodology enabled simultaneous Extractions using different SPs without compromising the method reproducibility, which increases the overall sample throughput. The method was characterized by low limits of detection, from 0.5 to 80 ng L−1, and adequate reproducibility, with inter-SP and inter-day relative standard deviation lower than 14%. Tap and lake water was successfully analyzed with the proposed methodology, resulting in relative recoveries of spiked samples ranging between 70.0 and 120%.
Marilena Musci - One of the best experts on this subject based on the ideXlab platform.
-
differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic Headspace Extraction followed by gas chromatography mass spectrometry analysis
Talanta, 2009Co-Authors: Federica Bianchi, Maria Careri, Marilena Musci, A Mangia, Monica Mattarozzi, Isabella Concina, M Falasconi, Emanuela Gobbi, M Pardo, G SberveglieriAbstract:The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic Headspace Extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene, o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic Headspace gas chromatography-mass spectrometry, showing a good agreement.
-
characterization of the aromatic profile for the authentication and differentiation of typical italian dry sausages
Talanta, 2007Co-Authors: Federica Bianchi, Maria Careri, Marilena Musci, C Cantoni, Luca Maria Chiesa, A PinnaAbstract:Abstract In order to chacterize two kinds of typical Italian dry-sausages, namely “Salame Mantovano” and “Salame Cremonese”, the volatile composition was determined for seven samples of “Salame Mantovano” and for five samples of “Salame Cremonese”. The study was performed by the dynamic Headspace Extraction technique (DHS) coupled with gas chromatography–mass spectrometry (GC–MS). Among the 104 volatiles identified, terpenes, aldehydes, ketones and alcohols represented the most abundant compounds. Peak area data for all the substances from the above mentioned group was used for statistical purposes. Firstly, principal component analysis (PCA) was carried out in order to visualize data trends and to detect possible clusters within samples. Then, linear discriminant analysis (LDA) was performed in order to detect the volatile compounds able to differentiate the two kinds of sausages investigated. The data obtained by GC–MS shows that the most important contributions to the differentiation of the two kinds of typical Italian salami were seven volatile compounds, i.e. 3-methylbutanal, 6-camphenol, dimethyl disulfide, 1-propene-3,3′-thiobis, ethyl propanoate, 1,4- p -menthadiene and 2,6-dimethyl-1,3,5,7-octatetraene. Prediction ability of the calculated model was estimated to be 100% by the “leave-one-out” cross-validation.
-
characterization of the volatile fraction and of free fatty acids of fontina valle d aosta a protected designation of origin italian cheese
Food Chemistry, 2007Co-Authors: Joel Berard, Federica Bianchi, Maria Careri, Augusto Chatel, Alessandro Mangia, Marilena MusciAbstract:Abstract The characterization of the volatile fraction of 24 samples of “Fontina Valle d’Aosta”, a protected designation of origin (PDO) semi-hard Italian cheese, was performed using the dynamic Headspace Extraction technique coupled with gas chromatography–mass spectrometry. Seventy-four volatile compounds, belonging to several chemical classes, mainly alcohols, sulfur and carboxylic compounds, were identified, allowing characterization of the distinct flavour of “Fontina Valle d’Aosta PDO” cheese. The characterization of the cheese was done also in terms of free fatty acids and the mechanism of formation of some classes of compounds is considered. Determinations of fat, N-Kjeldhal and dry matter were also carried out in order to obtain a more complete description of the properties of this PDO Italian cheese.
-
volatile norisoprenoids as markers of botanical origin of sardinian strawberry tree arbutus unedo l honey characterisation of aroma compounds by dynamic Headspace Extraction and gas chromatography mass spectrometry
Food Chemistry, 2005Co-Authors: Federica Bianchi, Maria Careri, Marilena MusciAbstract:Abstract In order to characterize and authenticate the aromatic profile of strawberry-tree ( Arbutus unedo L.) honey, a dynamic Headspace (DHS) Extraction, followed by gas chromatography–mass spectrometry (GC–MS) analysis, was performed on 10 Sardinian strawberry-tree ( Arbutus unedo L.) honey samples. A total of 28 aroma compounds were identified, but only norisoprenoid compounds such as α-isophorone, β-isophorone and 4-oxoisophorone, were recognized as specific floral origin markers of the strawberry-tree honey. The α-isophorone/β-isophorone ratio varied from 4 to 8, whereas the α-isophorone/4-oxoisophorone ratio was found to range from 11 to 20. The DHS Extraction method was proposed as a valid alternative to pollen analysis for floral source detection, especially for products like strawberry-tree honey, characterized by a low pollen content.
Gavin L. Sacks - One of the best experts on this subject based on the ideXlab platform.
-
Spatially Resolved Headspace Extractions of Trace-Level Volatiles from Planar Surfaces for High-Throughput Quantitation and Mass Spectral Imaging
2019Co-Authors: Jessica P. Rafson, Madeleine Y. Bee, Gavin L. SacksAbstract:The use of Headspace thin-film microExtraction devices (SPMESH) for parallel Extraction of trace-level volatiles prior to direct analysis in real-time mass spectrometry (DART-MS) has been reported previously, in which volatiles were extracted from samples in multi-well plates. In this report, we demonstrate that Headspace Extraction of volatiles by SPMESH sheets can be performed directly from planar surfaces. When coupled with DART-MS, this approach yields volatile mass spectral images with at least 4 mm resolution. When samples were spotted onto general-purpose silica gel thin-layer chromatography (TLC) plates, the SPMESH Extraction could reach equilibrium within 2–4 min and 48 samples could be extracted and analyzed in 14 min. Because volatilization of analytes from TLC plates was very rapid, SPMESH Extraction was delayed by the addition of 5% polyethylene glycol. Good linearity was achieved in the microgram per liter to milligram per liter range for four odorants (3-isobutyl-2-methoxypyrazine, linalool, methyl anthranilate, and o-aminoacetophenone) in several matrices (water, 10% ethanol, juice, and grape macerate) using 5 μL sample sizes. Detection limits as low as 50 pg/spot (10 μg/L in grape macerate) could be achieved. In contrast to many reports on Headspace solid-phase microExtraction, negligible matrix effects were observed for ethanol and grape macerates compared to water. SPMESH can preserve volatile images from planar surfaces, and SPMESH–DART-MS from TLC plates is well-suited for rapid trace volatile analysis, especially with small sample sizes
-
Parallel Headspace Extraction onto Etched Sorbent Sheets Prior to Ambient-Ionization Mass Spectrometry for Automated, Trace-Level Volatile Analyses.
Analytical chemistry, 2018Co-Authors: Madeleine Y. Bee, Jillian A. Jastrzembski, Gavin L. SacksAbstract:Headspace (HS) Extraction and preconcentration of volatiles by solid-phase microExtraction (SPME) can improve the sensitivity and selectivity of ambient ionization-mass spectrometry approaches like direct analysis in real time (DART), but previous approaches to HS-SPME-DART-MS have been challenging to automate. This report describes the production of inexpensive, reusable solid-phase mesh-enhanced sorption from Headspace (SPMESH) sheets by laser-etching mesh patterns into poly(dimethylsiloxane) (PDMS) sheets. Parallel Headspace Extraction of volatiles from multiple samples can be achieved by positioning the SPMESH sheets over multiwell plates and then attaching to a positioning stage for automated DART-MS quantitation. Using three representative odorants (3-isobutyl-2-methoxypyrazine, linalool, and methyl anthranilate), we achieved μg/L–ng/L detection limits with SPMESH-DART-MS, with the DART-MS step requiring only 17 min for 24 samples. Acceptable repeatability (24% or less day-to-day variation) and exce...
-
Parallel Headspace Extraction onto Etched Sorbent Sheets Prior to Ambient-Ionization Mass Spectrometry for Automated, Trace-Level Volatile Analyses
2018Co-Authors: Madeleine Y. Bee, Jillian A. Jastrzembski, Gavin L. SacksAbstract:Headspace (HS) Extraction and preconcentration of volatiles by solid-phase microExtraction (SPME) can improve the sensitivity and selectivity of ambient ionization-mass spectrometry approaches like direct analysis in real time (DART), but previous approaches to HS-SPME-DART-MS have been challenging to automate. This report describes the production of inexpensive, reusable solid-phase mesh-enhanced sorption from Headspace (SPMESH) sheets by laser-etching mesh patterns into poly(dimethylsiloxane) (PDMS) sheets. Parallel Headspace Extraction of volatiles from multiple samples can be achieved by positioning the SPMESH sheets over multiwell plates and then attaching to a positioning stage for automated DART-MS quantitation. Using three representative odorants (3-isobutyl-2-methoxypyrazine, linalool, and methyl anthranilate), we achieved μg/L–ng/L detection limits with SPMESH-DART-MS, with the DART-MS step requiring only 17 min for 24 samples. Acceptable repeatability (24% or less day-to-day variation) and excellent recovery from a grape matrix (99–106%) could be achieved. Through use of a Teflon gasket and stainless steel spacers, cross-contamination between the Headspaces of adjacent wells could be limited to roughly 1%. Optimum SPMESH Extraction and desorption parameters were determined by response surface methodology. In summary, sheet-based SPMESH provides a sensitive, readily automated approach for coupling with DART-MS and achieving high-throughput trace-level volatile analyses
-
trace level volatile quantitation by direct analysis in real time mass spectrometry following Headspace Extraction optimization and validation in grapes
Journal of Agricultural and Food Chemistry, 2017Co-Authors: Jillian A. Jastrzembski, Madeleine Y. Bee, Gavin L. SacksAbstract:Ambient ionization mass spectrometric (AI-MS) techniques like direct analysis in real time (DART) offer the potential for rapid quantitative analyses of trace volatiles in food matrices, but performance is generally limited by the lack of preconcentration and Extraction steps. The sensitivity and selectivity of AI-MS approaches can be improved through solid-phase microExtraction (SPME) with appropriate thin-film geometries, for example, solid-phase mesh-enhanced sorption from Headspace (SPMESH). This work improves the SPMESH-DART-MS approach for use in food analyses and validates the approach for trace volatile analysis for two compounds in real samples (grape macerates). SPMESH units prepared with different sorbent coatings were evaluated for their ability to extract a range of odor-active volatiles, with poly(dimethylsiloxane)/divinylbenzene giving the most satisfactory results. In combination with high-resolution mass spectrometry (HRMS), detection limits for SPMESH-DART-MS under 4 ng/L in less than 30...
Federica Bianchi - One of the best experts on this subject based on the ideXlab platform.
-
differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic Headspace Extraction followed by gas chromatography mass spectrometry analysis
Talanta, 2009Co-Authors: Federica Bianchi, Maria Careri, Marilena Musci, A Mangia, Monica Mattarozzi, Isabella Concina, M Falasconi, Emanuela Gobbi, M Pardo, G SberveglieriAbstract:The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic Headspace Extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene, o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic Headspace gas chromatography-mass spectrometry, showing a good agreement.
-
characterization of the aromatic profile for the authentication and differentiation of typical italian dry sausages
Talanta, 2007Co-Authors: Federica Bianchi, Maria Careri, Marilena Musci, C Cantoni, Luca Maria Chiesa, A PinnaAbstract:Abstract In order to chacterize two kinds of typical Italian dry-sausages, namely “Salame Mantovano” and “Salame Cremonese”, the volatile composition was determined for seven samples of “Salame Mantovano” and for five samples of “Salame Cremonese”. The study was performed by the dynamic Headspace Extraction technique (DHS) coupled with gas chromatography–mass spectrometry (GC–MS). Among the 104 volatiles identified, terpenes, aldehydes, ketones and alcohols represented the most abundant compounds. Peak area data for all the substances from the above mentioned group was used for statistical purposes. Firstly, principal component analysis (PCA) was carried out in order to visualize data trends and to detect possible clusters within samples. Then, linear discriminant analysis (LDA) was performed in order to detect the volatile compounds able to differentiate the two kinds of sausages investigated. The data obtained by GC–MS shows that the most important contributions to the differentiation of the two kinds of typical Italian salami were seven volatile compounds, i.e. 3-methylbutanal, 6-camphenol, dimethyl disulfide, 1-propene-3,3′-thiobis, ethyl propanoate, 1,4- p -menthadiene and 2,6-dimethyl-1,3,5,7-octatetraene. Prediction ability of the calculated model was estimated to be 100% by the “leave-one-out” cross-validation.
-
characterization of the volatile fraction and of free fatty acids of fontina valle d aosta a protected designation of origin italian cheese
Food Chemistry, 2007Co-Authors: Joel Berard, Federica Bianchi, Maria Careri, Augusto Chatel, Alessandro Mangia, Marilena MusciAbstract:Abstract The characterization of the volatile fraction of 24 samples of “Fontina Valle d’Aosta”, a protected designation of origin (PDO) semi-hard Italian cheese, was performed using the dynamic Headspace Extraction technique coupled with gas chromatography–mass spectrometry. Seventy-four volatile compounds, belonging to several chemical classes, mainly alcohols, sulfur and carboxylic compounds, were identified, allowing characterization of the distinct flavour of “Fontina Valle d’Aosta PDO” cheese. The characterization of the cheese was done also in terms of free fatty acids and the mechanism of formation of some classes of compounds is considered. Determinations of fat, N-Kjeldhal and dry matter were also carried out in order to obtain a more complete description of the properties of this PDO Italian cheese.
-
volatile norisoprenoids as markers of botanical origin of sardinian strawberry tree arbutus unedo l honey characterisation of aroma compounds by dynamic Headspace Extraction and gas chromatography mass spectrometry
Food Chemistry, 2005Co-Authors: Federica Bianchi, Maria Careri, Marilena MusciAbstract:Abstract In order to characterize and authenticate the aromatic profile of strawberry-tree ( Arbutus unedo L.) honey, a dynamic Headspace (DHS) Extraction, followed by gas chromatography–mass spectrometry (GC–MS) analysis, was performed on 10 Sardinian strawberry-tree ( Arbutus unedo L.) honey samples. A total of 28 aroma compounds were identified, but only norisoprenoid compounds such as α-isophorone, β-isophorone and 4-oxoisophorone, were recognized as specific floral origin markers of the strawberry-tree honey. The α-isophorone/β-isophorone ratio varied from 4 to 8, whereas the α-isophorone/4-oxoisophorone ratio was found to range from 11 to 20. The DHS Extraction method was proposed as a valid alternative to pollen analysis for floral source detection, especially for products like strawberry-tree honey, characterized by a low pollen content.
Karlheinz Engel - One of the best experts on this subject based on the ideXlab platform.
-
Analysis and Sensory Evaluation of Volatile Constituents of Fresh Blackcurrant (Ribes nigrum L.) Fruits.
Journal of agricultural and food chemistry, 2017Co-Authors: Kathrin Jung, Oxana Fastowski, Iulia Poplacean, Karlheinz EngelAbstract:Volatile constituents of fresh blackcurrant (Ribes nigrum L.) berries were isolated via vacuum-Headspace Extraction and analyzed by capillary gas chromatography–mass spectrometry. In agreement with previous studies with frozen fruits, short-chain esters and terpenes were major compound classes. However, rather high concentrations of C6-compounds (e.g., (E)-hex-2-enal, (Z)-hex-3-enal) constituted a striking difference to data reported for frozen fruits. Frozen storage of blackcurrant berries was shown to result in drastically reduced concentrations of C6-compounds and a shift of the volatile profile in favor of terpenes. The time-dependent enzymatic formation and isomerization of C6-compounds adds an additional element of variability to the spectrum of fresh blackcurrant volatiles. Nevertheless, blackcurrant cultivars can be classified according to the major classes of the volatiles of the fresh fruits, if prerequisites, such as the same growing location and the same state of ripeness, are met. The sensory...
-
Analysis and Sensory Evaluation of Volatile Constituents of Fresh Blackcurrant (Ribes nigrum L.) Fruits
2017Co-Authors: Kathrin Jung, Oxana Fastowski, Iulia Poplacean, Karlheinz EngelAbstract:Volatile constituents of fresh blackcurrant (Ribes nigrum L.) berries were isolated via vacuum-Headspace Extraction and analyzed by capillary gas chromatography–mass spectrometry. In agreement with previous studies with frozen fruits, short-chain esters and terpenes were major compound classes. However, rather high concentrations of C6-compounds (e.g., (E)-hex-2-enal, (Z)-hex-3-enal) constituted a striking difference to data reported for frozen fruits. Frozen storage of blackcurrant berries was shown to result in drastically reduced concentrations of C6-compounds and a shift of the volatile profile in favor of terpenes. The time-dependent enzymatic formation and isomerization of C6-compounds adds an additional element of variability to the spectrum of fresh blackcurrant volatiles. Nevertheless, blackcurrant cultivars can be classified according to the major classes of the volatiles of the fresh fruits, if prerequisites, such as the same growing location and the same state of ripeness, are met. The sensory contributions of volatiles of blackcurrant berries were assessed by gas chromatography–olfactometry in combination with aroma extract dilution analysis. 4-Methoxy-2-methyl-2-butanethiol, (Z)-3-hexenal, ethyl butanoate, 1,8-cineole, oct-1-en-3-one, and alkyl-substituted 3-methoxypyrazines were among the volatiles showing the highest aroma activity values
-
occurrence of 4 methoxy 2 methyl 2 butanethiol in blackcurrant ribes nigrum l berries
Flavour and Fragrance Journal, 2016Co-Authors: Kathrin Jung, Oxana Fastowski, Karlheinz EngelAbstract:4-Methoxy-2-methyl-2-butanethiol is a powerful sulfur-containing aroma compound identified several decades ago in blackcurrant buds (Ribes nigrum L.). However, an unambiguous identification in blackcurrant fruits has been lacking. In this study the occurrence of 4-methoxy-2-methyl-2-butanethiol in blackcurrant berries has been demonstrated for the first time by the analysis of seven cultivars. After isolation of the volatiles by vacuum-Headspace-Extraction, the sulfur-containing compound was enriched on mercurated agarose gel. Identification was performed via capillary gas chromatography/mass spectrometry. Quantitation was performed in the single ion monitoring mode using 4-methyl-4-sulfanylpentan-2-one as internal standard. The concentration of 4-methoxy-2-methyl-2-butanethiol in Andega (4.5 µg/kg) was significantly higher than those in the other cultivars investigated in this study (from 0.16 to 0.72 µg/kg). Calculation of the odour activity values indicated that this sulfur-containing volatile contributes to the aroma of blackcurrant berries. Copyright © 2016 John Wiley & Sons, Ltd.
-
analysis and sensory evaluation of gooseberry ribes uva crispa l volatiles
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Katrin Hempfling, Oxana Fastowski, Markus Kopp, Martin Pour Nikfardjam, Karlheinz EngelAbstract:Volatiles of gooseberries (Ribes uva cripsa L.) were isolated by means of vacuum-Headspace-Extraction, and the obtained concentrates were analyzed via capillary gas chromatography–mass spectrometry. To ensure the quantitation of highly volatile compounds, Headspace analysis was additionally performed on selected batches. C6-components (e.g., (Z)-hex-3-enal, (E)-hex-2-enal), derived from lipid oxidation, and short-chain esters (e.g., ethyl acetate, methyl butanoate, ethyl butanoate) turned out to be the major compound classes in the fresh fruit. The compositional variability was demonstrated by analyzing several gooseberry varieties at different stages of ripeness. The contributions of volatiles to the gooseberry aroma were assessed by using gas chromatography–olfactometry in combination with aroma extract dilution analysis and calculation of odor activity values. C6-components and esters were shown to be responsible for the green and fruity character of fresh gooseberries.
