Concentrates of dried fig (Ficus carica L.) and dried date (Phoenix dactylifera L.) fruits were o... more Concentrates of dried fig (Ficus carica L.) and dried date (Phoenix dactylifera L.) fruits were obtained by solvent extraction (pentane: dichloromethane, 2:1 by vol) and subsequently analysed by HRGC-MS. Using multidimensional gas chromatography (DB-Wax/oktakis2, 6-di-O-methyl-3-O-pentyl-?-cyclodextrin) simultaneous enantiodifferentiation of 4,5-dihydroxyhexanoic acid-?-lactone isomers (solerol) was carried out. The presence of this constituent is reported for the first time in figs and dates.
Abstract The chromatographic separation of racemic mixtures of volatile compounds by 2, 3, 6-trim... more Abstract The chromatographic separation of racemic mixtures of volatile compounds by 2, 3, 6-trimethyl-α-, β-and γ-cyclodextrins is discussed. Columns were prepared by mixing the derivatized cyclodextrin with OV-1701 or hydroxy-terminated OV-1701 (OV-1701-OH) ...
The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME-GC... more The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME-GC-MS to define fingerprinting and identify chemical markers and/or indices of ageing and aroma quality. In particular, four non-aromatic (Carnaroli, Carnise, Cerere and Antares) and two aromatic (Apollo and Venere) rices, harvested in 2010 and 2011, were monitored over 12months. Twenty-five aroma components were considered and, despite considerable inter-annual variability, some of them showed similar trends over time, including 2-(E)-octenal as a marker of ageing for all cultivars, and heptanal, octanal and 2-ethyl hexanol as cultivar-specific indicators. The area ratios 2-acetyl-1-pyrroline/1-octen-3-ol, for Venere, and 3-methyl-1-butanol/2-methyl-1-butanol, for Apollo, were also found to act as ageing indices. Additional information on release of key-aroma compounds was also obtained from quantitation and its dependence on grain shape and chemical composition. Heptanal/1-octen-3-ol and heptanal/octanal ratios were also defined as characterising the aroma quality indices of the six Italian rice cultivars investigated.
This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species a... more This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species and origin (Iris germanica (Morocco), I. albicans (Morocco), I. pallida (Morocco), I. pallida (China), I. pallida (Italy)) by applying a strategy derived from those adopted in metabolomics. The specimens' fingerprints from conventional analysis methods (LC-UV and/or LC-MS) were unable to provide clear discrimination. A strategy combining UHPLC/TOF-HRMS, in positive and negative modes, with multivariate statistical methods was therefore applied. Exact mass/retention time (EMRT) pairs obtained by UHPLC-TOF/HRMS were successfully submitted to statistical processing by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and then orthogonal partial least square-discriminant analysis (OPLS-DA), to extract the discriminating EMRT pairs through their trend views. 146 EMRT pairs were selected on the basis of their trend views, because they significantly var...
Journal of Chromatography A - J CHROMATOGR A, 2004
This study applies Ultrafast module-GC (UFM-GC) with direct resistively heated columns to routine... more This study applies Ultrafast module-GC (UFM-GC) with direct resistively heated columns to routine analysis of a group of essential oils of differing complexities (chamomile, peppermint, rosemary and sage). Essential oils were analysed by conventional GC with conventional inner diameter (i.d.) columns (0.25mm) of different lengths (5 and 25m long) and by Fast GC and Ultrafast module-GC with narrow bore columns (0.1mm i.d., 5m long). Column performance were evaluated and compared through their Grob test, separation number and peak capacity. Ultrafast module-GC was successful in the qualitative and quantitative analysis of essential oils of different compositions with analysis times between 40s and 2min versus 20–60min required by conventional GC. Critical pairs or groups of components were separated by carefully tuning selectivity of the stationary phase to compensate for loss of efficiency due to the use of short columns and high temperature rates. The Ultrafast module-GC results of ...
The ratio of the responses of two different specific detectors to a single compound has, when use... more The ratio of the responses of two different specific detectors to a single compound has, when used in conjunction with the compound's retention index, been investigated as an identification criterion for the compound. The ECD: NPD and ECD: FPD response ratios ...
This study investigates the applicability of an iterative approach aimed at defining a chemical b... more This study investigates the applicability of an iterative approach aimed at defining a chemical blueprint of virgin olive oil volatiles to be correlated to the product sensory quality. The investigation strategy proposed allows to fully exploit the informative content of a comprehensive multidimensional gas chromatography (GC×GC) coupled to a mass spectrometry (MS) data set. Olive oil samples (19), including 5 reference standards, obtained from the International Olive Oil Council, and commercial samples, were submitted to a sensory evaluation by a Panel test, before being analyzed in two laboratories using different instrumentation, column set, and software elaboration packages in view of a cross-validation of the entire methodology. A first classification of samples based on untargeted peak features information, was obtained on raw data from two different column combinations (apolar×polar and polar×apolar) by applying unsupervised multivariate analysis (i.e., principal component analysis-PCA). However, to improve effectiveness and specificity of this classification, peak features were reliably identified (261 compounds), on the basis of the MS spectrum and linear retention index matching, and subjected to successive pair-wise comparisons based on 2D patterns, which revealed peculiar distribution of chemicals correlated with samples sensory classification. The most informative compounds were thus identified and collected in a "blueprint" of specific defects (or combination of defects) successively adopted to discriminate Extra Virgin from defected oils (i.e., lampante oil) with the aid of a supervised approach, i.e., partial least squares-discriminant analysis (PLS-DA). In this last step, the principles of sensomics, which assigns higher information potential to analytes with lower odor threshold proved to be successful, and a much more powerful discrimination of samples was obtained in view of a sensory quality assessment.
In extracts obtained by liquid-liquid extraction and enzymatic hydrolysis from five apple cultiva... more In extracts obtained by liquid-liquid extraction and enzymatic hydrolysis from five apple cultivars (Renao; Bedan; Peau de Chien; Noel des Champs; Red Delicious), chiral evaluation of free and glycosidically-bound octane-1,3-diol and 5(Z)-octene-1,3-diol, as well as ethyl 3-hydroxyoctanoate and ethyl 5(Z)-3-hydroxyoctenoate, was performed by multidimensional gas chromatography (MDGC), combining a polar achiral column (DB-Wax) with a chiral main column (2,3-di-O-acetyl-6-O-tert. butyldimethylsilyl-β-cyclodextrin/OV
This article reviews papers published over the period 1995-1998 dealing with the application of c... more This article reviews papers published over the period 1995-1998 dealing with the application of cyclodextrin derivatives (CDs) as chiral selector for direct enantiomer GC separation of volatile optically active components in the essential oil, extract, flavour and aroma fields. For each application, the racemate analysed, the CD employed as chiral selector and the matrix investigated are reported. The applications are grouped by analytical technique employed: capillary gas chromatography and capillary gas chromatography-mass spectrometry (GC and GC-MS); two-dimensional gas chromatography (GC x GC); capillary gas chromatography-isotope ratio-mass spectrometry (GC-IRMS); liquid chromatography-capillary gas chromatography (LC-GC).
The study compares standard addition (SA), stable isotope dilution assay (SIDA) and multiple head... more The study compares standard addition (SA), stable isotope dilution assay (SIDA) and multiple headspace extraction (MHE) as methods to quantify furan and 2-methyl-furan in roasted coffee with HS-SPME-GC-MS, using CAR-PDMS as fibre coating, d(4)-furan as internal standard and in-fibre internal standardization with n-undecane to check the fibre reliability. The results on about 150 samples calculated with the three quantitation approaches were all very satisfactory, with coefficient of variation (CV) versus the U.S. Food and Drug Administration (FDA) method, taken as reference, almost always below the arbitrarily-fixed limit of 15%. Furan was detected in the 1-5 ppm range, 2-methyl-furan in the 4-20 ppm range. Moreover, experimental exponential slopes (Q) and linearity (r) of both furan and 2-methyl-furan MHE regression equation on 50 samples were very similar thus making possible to use the same average Q value for all samples of the investigated set and their quantitation with a single determination. This makes this approach very rapid and competitive in-time with SA and SIDA. A non-separative method (HS-SPME-MS) was also developed in view of possible application on-line monitoring of furan and 2-methyl-furan in a pilot-plant with the aim of optimizing the roasting process to reduce these compounds to a minimum. Sampling times of 20 and 5 min were tested, the latter enabling total analysis time to be reduced to about 9 min. The results on 105 samples with both SIDA and MHE approaches were again highly satisfactory most of the samples giving a CV% versus the conventional methods below 20%. In this case too average Q values for both furan and 2-methyl-furan were used for MHE. The separative method presented very good repeatability (RSD% always below 10%) and intermediate precision over three months (RSD% always below 15%); performance were similar for the non-separative method, with repeatability (RSD%) always below 12% and intermediate precision over three months (RSD%) always below 15%. The sensitivity of both separative and non-separative methods was also very good, LOD and LOQ being in the ppb range for both furan and 2-methyl-furan, i.e. well below the amounts present in the roasted coffee samples.
The study aimed to find the best trade-off between separation of the most critical peak pair and ... more The study aimed to find the best trade-off between separation of the most critical peak pair and analysis time, in enantioselective GCFID and GCMS analysis of lavender essential oil, using the GC method-translation approach. Analysis conditions were first optimized for ...
The analysis of complex real-world samples of vegetable origin requires rapid and accurate routin... more The analysis of complex real-world samples of vegetable origin requires rapid and accurate routine methods, enabling laboratories to increase sample throughput and productivity while reducing analysis costs. This study examines shortening enantioselective-GC (ES-GC) ...
The essential oils of Ridolfia segetum (L.) Moris and Oenanthe crocata L. (Apiaceae), collected i... more The essential oils of Ridolfia segetum (L.) Moris and Oenanthe crocata L. (Apiaceae), collected in Sardinia (Italy), have been assayed for two enzyme-associated activities of the HIV-1 reverse transcriptase (RT): RNA-dependent DNA polymerase (RDDP) activity and ribonuclease H ...
Concentrates of dried fig (Ficus carica L.) and dried date (Phoenix dactylifera L.) fruits were o... more Concentrates of dried fig (Ficus carica L.) and dried date (Phoenix dactylifera L.) fruits were obtained by solvent extraction (pentane: dichloromethane, 2:1 by vol) and subsequently analysed by HRGC-MS. Using multidimensional gas chromatography (DB-Wax/oktakis2, 6-di-O-methyl-3-O-pentyl-?-cyclodextrin) simultaneous enantiodifferentiation of 4,5-dihydroxyhexanoic acid-?-lactone isomers (solerol) was carried out. The presence of this constituent is reported for the first time in figs and dates.
Abstract The chromatographic separation of racemic mixtures of volatile compounds by 2, 3, 6-trim... more Abstract The chromatographic separation of racemic mixtures of volatile compounds by 2, 3, 6-trimethyl-α-, β-and γ-cyclodextrins is discussed. Columns were prepared by mixing the derivatized cyclodextrin with OV-1701 or hydroxy-terminated OV-1701 (OV-1701-OH) ...
The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME-GC... more The volatile fractions of six Italian high-quality rice cultivars were investigated by HS-SPME-GC-MS to define fingerprinting and identify chemical markers and/or indices of ageing and aroma quality. In particular, four non-aromatic (Carnaroli, Carnise, Cerere and Antares) and two aromatic (Apollo and Venere) rices, harvested in 2010 and 2011, were monitored over 12months. Twenty-five aroma components were considered and, despite considerable inter-annual variability, some of them showed similar trends over time, including 2-(E)-octenal as a marker of ageing for all cultivars, and heptanal, octanal and 2-ethyl hexanol as cultivar-specific indicators. The area ratios 2-acetyl-1-pyrroline/1-octen-3-ol, for Venere, and 3-methyl-1-butanol/2-methyl-1-butanol, for Apollo, were also found to act as ageing indices. Additional information on release of key-aroma compounds was also obtained from quantitation and its dependence on grain shape and chemical composition. Heptanal/1-octen-3-ol and heptanal/octanal ratios were also defined as characterising the aroma quality indices of the six Italian rice cultivars investigated.
This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species a... more This study aimed to discriminate 22 samples of commercial Iris rhizomes (orris root) by species and origin (Iris germanica (Morocco), I. albicans (Morocco), I. pallida (Morocco), I. pallida (China), I. pallida (Italy)) by applying a strategy derived from those adopted in metabolomics. The specimens' fingerprints from conventional analysis methods (LC-UV and/or LC-MS) were unable to provide clear discrimination. A strategy combining UHPLC/TOF-HRMS, in positive and negative modes, with multivariate statistical methods was therefore applied. Exact mass/retention time (EMRT) pairs obtained by UHPLC-TOF/HRMS were successfully submitted to statistical processing by principal component analysis (PCA), partial least square discriminant analysis (PLS-DA), and then orthogonal partial least square-discriminant analysis (OPLS-DA), to extract the discriminating EMRT pairs through their trend views. 146 EMRT pairs were selected on the basis of their trend views, because they significantly var...
Journal of Chromatography A - J CHROMATOGR A, 2004
This study applies Ultrafast module-GC (UFM-GC) with direct resistively heated columns to routine... more This study applies Ultrafast module-GC (UFM-GC) with direct resistively heated columns to routine analysis of a group of essential oils of differing complexities (chamomile, peppermint, rosemary and sage). Essential oils were analysed by conventional GC with conventional inner diameter (i.d.) columns (0.25mm) of different lengths (5 and 25m long) and by Fast GC and Ultrafast module-GC with narrow bore columns (0.1mm i.d., 5m long). Column performance were evaluated and compared through their Grob test, separation number and peak capacity. Ultrafast module-GC was successful in the qualitative and quantitative analysis of essential oils of different compositions with analysis times between 40s and 2min versus 20–60min required by conventional GC. Critical pairs or groups of components were separated by carefully tuning selectivity of the stationary phase to compensate for loss of efficiency due to the use of short columns and high temperature rates. The Ultrafast module-GC results of ...
The ratio of the responses of two different specific detectors to a single compound has, when use... more The ratio of the responses of two different specific detectors to a single compound has, when used in conjunction with the compound's retention index, been investigated as an identification criterion for the compound. The ECD: NPD and ECD: FPD response ratios ...
This study investigates the applicability of an iterative approach aimed at defining a chemical b... more This study investigates the applicability of an iterative approach aimed at defining a chemical blueprint of virgin olive oil volatiles to be correlated to the product sensory quality. The investigation strategy proposed allows to fully exploit the informative content of a comprehensive multidimensional gas chromatography (GC×GC) coupled to a mass spectrometry (MS) data set. Olive oil samples (19), including 5 reference standards, obtained from the International Olive Oil Council, and commercial samples, were submitted to a sensory evaluation by a Panel test, before being analyzed in two laboratories using different instrumentation, column set, and software elaboration packages in view of a cross-validation of the entire methodology. A first classification of samples based on untargeted peak features information, was obtained on raw data from two different column combinations (apolar×polar and polar×apolar) by applying unsupervised multivariate analysis (i.e., principal component analysis-PCA). However, to improve effectiveness and specificity of this classification, peak features were reliably identified (261 compounds), on the basis of the MS spectrum and linear retention index matching, and subjected to successive pair-wise comparisons based on 2D patterns, which revealed peculiar distribution of chemicals correlated with samples sensory classification. The most informative compounds were thus identified and collected in a "blueprint" of specific defects (or combination of defects) successively adopted to discriminate Extra Virgin from defected oils (i.e., lampante oil) with the aid of a supervised approach, i.e., partial least squares-discriminant analysis (PLS-DA). In this last step, the principles of sensomics, which assigns higher information potential to analytes with lower odor threshold proved to be successful, and a much more powerful discrimination of samples was obtained in view of a sensory quality assessment.
In extracts obtained by liquid-liquid extraction and enzymatic hydrolysis from five apple cultiva... more In extracts obtained by liquid-liquid extraction and enzymatic hydrolysis from five apple cultivars (Renao; Bedan; Peau de Chien; Noel des Champs; Red Delicious), chiral evaluation of free and glycosidically-bound octane-1,3-diol and 5(Z)-octene-1,3-diol, as well as ethyl 3-hydroxyoctanoate and ethyl 5(Z)-3-hydroxyoctenoate, was performed by multidimensional gas chromatography (MDGC), combining a polar achiral column (DB-Wax) with a chiral main column (2,3-di-O-acetyl-6-O-tert. butyldimethylsilyl-β-cyclodextrin/OV
This article reviews papers published over the period 1995-1998 dealing with the application of c... more This article reviews papers published over the period 1995-1998 dealing with the application of cyclodextrin derivatives (CDs) as chiral selector for direct enantiomer GC separation of volatile optically active components in the essential oil, extract, flavour and aroma fields. For each application, the racemate analysed, the CD employed as chiral selector and the matrix investigated are reported. The applications are grouped by analytical technique employed: capillary gas chromatography and capillary gas chromatography-mass spectrometry (GC and GC-MS); two-dimensional gas chromatography (GC x GC); capillary gas chromatography-isotope ratio-mass spectrometry (GC-IRMS); liquid chromatography-capillary gas chromatography (LC-GC).
The study compares standard addition (SA), stable isotope dilution assay (SIDA) and multiple head... more The study compares standard addition (SA), stable isotope dilution assay (SIDA) and multiple headspace extraction (MHE) as methods to quantify furan and 2-methyl-furan in roasted coffee with HS-SPME-GC-MS, using CAR-PDMS as fibre coating, d(4)-furan as internal standard and in-fibre internal standardization with n-undecane to check the fibre reliability. The results on about 150 samples calculated with the three quantitation approaches were all very satisfactory, with coefficient of variation (CV) versus the U.S. Food and Drug Administration (FDA) method, taken as reference, almost always below the arbitrarily-fixed limit of 15%. Furan was detected in the 1-5 ppm range, 2-methyl-furan in the 4-20 ppm range. Moreover, experimental exponential slopes (Q) and linearity (r) of both furan and 2-methyl-furan MHE regression equation on 50 samples were very similar thus making possible to use the same average Q value for all samples of the investigated set and their quantitation with a single determination. This makes this approach very rapid and competitive in-time with SA and SIDA. A non-separative method (HS-SPME-MS) was also developed in view of possible application on-line monitoring of furan and 2-methyl-furan in a pilot-plant with the aim of optimizing the roasting process to reduce these compounds to a minimum. Sampling times of 20 and 5 min were tested, the latter enabling total analysis time to be reduced to about 9 min. The results on 105 samples with both SIDA and MHE approaches were again highly satisfactory most of the samples giving a CV% versus the conventional methods below 20%. In this case too average Q values for both furan and 2-methyl-furan were used for MHE. The separative method presented very good repeatability (RSD% always below 10%) and intermediate precision over three months (RSD% always below 15%); performance were similar for the non-separative method, with repeatability (RSD%) always below 12% and intermediate precision over three months (RSD%) always below 15%. The sensitivity of both separative and non-separative methods was also very good, LOD and LOQ being in the ppb range for both furan and 2-methyl-furan, i.e. well below the amounts present in the roasted coffee samples.
The study aimed to find the best trade-off between separation of the most critical peak pair and ... more The study aimed to find the best trade-off between separation of the most critical peak pair and analysis time, in enantioselective GCFID and GCMS analysis of lavender essential oil, using the GC method-translation approach. Analysis conditions were first optimized for ...
The analysis of complex real-world samples of vegetable origin requires rapid and accurate routin... more The analysis of complex real-world samples of vegetable origin requires rapid and accurate routine methods, enabling laboratories to increase sample throughput and productivity while reducing analysis costs. This study examines shortening enantioselective-GC (ES-GC) ...
The essential oils of Ridolfia segetum (L.) Moris and Oenanthe crocata L. (Apiaceae), collected i... more The essential oils of Ridolfia segetum (L.) Moris and Oenanthe crocata L. (Apiaceae), collected in Sardinia (Italy), have been assayed for two enzyme-associated activities of the HIV-1 reverse transcriptase (RT): RNA-dependent DNA polymerase (RDDP) activity and ribonuclease H ...
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