The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

José-maría González-sáiz - One of the best experts on this subject based on the ideXlab platform.

  • A simple and sensitive vortex assisted liquid-liquid microextraction method for the simultaneous determination of haloanisoles and halophenols in wines.
    Talanta, 2014
    Co-Authors: Consuelo Pizarro, N. Pérez-del-notario, A. Sáenz-mateo, José-maría González-sáiz
    Abstract:

    A vortex assisted liquid-liquid microextraction (VALLME) method was developed and optimised for the determination of the main compounds that can cause Cork Taint in wines, 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA); and their corresponding halophenolic precursors. Target compounds were determined by gas chromatography combined with a micro-electron capture detector (GC-µECD) system. Halophenol extraction and derivatisation processes were performed at the same time. To optimise the VALLME method, the extraction solvent was selected. Then, the other parameters of influence, such as volume of extraction solvent and derivatisation agent, salt addition and vortex time were optimised using a central composite design combined with desirability functions. Once the optimal conditions had been determined, the method was validated, showing satisfactory linearity (with correlation coefficients over 0.983), repeatability (below 10.0%) and reproducibility (below 11.2%). Detection limits obtained were lower than the olfactory threshold of the studied compounds, being similar or even lower than previously reported with the advantage of reducing the extraction time. The analysis of real wine samples demonstrated the applicability of the method. To our knowledge, this is the first time that VALLME has been applied for the simultaneous determination of haloanisoles and halophenols in wine.

  • Simultaneous determination of Cork Taint and Brett character responsible compounds in wine using ultrasound-assisted emulsification microextraction with solidification of floating organic drop.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this study, ultrasound-assisted emulsification microextraction combined with solidification of floating organic drop method (USAEME–SFOD) has been proposed as a novel approach for the sensitive determination of haloanisoles and volatile phenols in wines. For this purpose, the influence of the different parameters affecting the procedure (type and volume of extraction solvent, temperature, time and ionic strength) was evaluated in order to optimise the efficiency of the process. Subsequently, the linearity, detection and quantification limits, precision, recoveries and applicability to real samples were studied, obtaining excellent method performance results. Moreover, USAEME–SFOD was compared with other liquid–liquid microextraction methods such as dispersive liquid–liquid microextraction (DLLME) and ultrasound-assisted emulsification microextraction (USAEME). This comparison study proved the suitability of USAEME–SFOD as an alternative to previously reported methods for the simultaneous determination of Cork Taint and Brett character responsible compounds in wines.

  • Microwave assisted extraction combined with dispersive liquid–liquid microextraction as a sensitive sample preparation method for the determination of haloanisoles and halophenols in Cork stoppers and oak barrel sawdust
    Food Chemistry, 2012
    Co-Authors: C Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this paper, a method based on microwave assisted extraction (MAE) in combination with dispersive liquid–liquid microextraction (DLLME) has been proposed as a new approach for the sensitive determination of Cork Taint responsible compounds in Cork stoppers and oak barrel sawdust. For this purpose, haloanisoles and halophenols were extracted from the solid samples using a MAE method. Subsequently, a DLLME-derivatisation procedure was applied on the MAE extracts and the analytes were determined by gas chromatography–electron capture detection (GC–ECD). Parameters affecting the DLLME-derivatisation method were exhaustively investigated by means of experimental design methodology. Once optimised, the proposed method showed satisfactory linearity (correlation coefficients over 0.991), repeatability (below 10.4%) and inter-day precision (below 11.2%). Detection limits obtained were similar or even lower than previously reported. The results obtained proved the suitability of the combination of MAE with DLLME as a sensitive sample preparation methodology for the analysis of haloanisoles and halophenols in solid enological matrices.

  • Optimisation of ultrasound-assisted emulsification microextraction method with solidification of floating organic drop for the analysis of Cork Taint responsible compounds in wine.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    This paper presents the optimisation of a method based on ultrasound assisted-emulsification method (USAEME) combined with solidification of floating organic drop (SFOD) for the sensitive determination of Cork Taint responsible compounds in wine. Haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) and their halophenolic precursors were determined by gas chromatography with electron capture detection (GC-ECD). The derivatisation of the halophenols was performed simultaneously with the extraction. To perform the optimisation, the main parameters affecting both extraction and derivatisation were exhaustively studied in different steps. Once the extraction solvent and the pH and time conditions had been determined, experimental design was applied for the simultaneous study of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Then, the analytical characteristics of the optimised method were evaluated achieving satisfactory linearity (with correlation coefficients over 0.984), repeatability (below 10.7%) and inter-day precision (below 10.6%) for all target analytes. Moreover, detection limits found were similar or even lower than the olfactory threshold of the studied compounds. Finally, the applicability of the proposed method was tested by analysing real wine samples. To the best of our knowledge, this is the first time that USAEME-SFOD method has been used to determine Cork Taint responsible compounds in wine.

  • Optimisation of a sensitive method based on ultrasound-assisted emulsification–microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected. Subsequently its volume, the ionic strength and the time and temperature at which the extraction must be performed were simultaneously evaluated by means of experimental design methodology. After optimisation step, the analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.989), repeatability (below 11.5%) and inter-day precision (below 11.7%) were obtained for all target analytes. For all the studied compounds, detection limits obtained were similar or even lower than previously reported. In addition, the developed method was successfully applied to the analysis of wine samples. To the best of our knowledge, this is the first time that USAEME has been applied to simultaneously determine the compounds responsible for Cork Taint and Brett character in wine.

Consuelo Pizarro - One of the best experts on this subject based on the ideXlab platform.

  • A simple and sensitive vortex assisted liquid-liquid microextraction method for the simultaneous determination of haloanisoles and halophenols in wines.
    Talanta, 2014
    Co-Authors: Consuelo Pizarro, N. Pérez-del-notario, A. Sáenz-mateo, José-maría González-sáiz
    Abstract:

    A vortex assisted liquid-liquid microextraction (VALLME) method was developed and optimised for the determination of the main compounds that can cause Cork Taint in wines, 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA); and their corresponding halophenolic precursors. Target compounds were determined by gas chromatography combined with a micro-electron capture detector (GC-µECD) system. Halophenol extraction and derivatisation processes were performed at the same time. To optimise the VALLME method, the extraction solvent was selected. Then, the other parameters of influence, such as volume of extraction solvent and derivatisation agent, salt addition and vortex time were optimised using a central composite design combined with desirability functions. Once the optimal conditions had been determined, the method was validated, showing satisfactory linearity (with correlation coefficients over 0.983), repeatability (below 10.0%) and reproducibility (below 11.2%). Detection limits obtained were lower than the olfactory threshold of the studied compounds, being similar or even lower than previously reported with the advantage of reducing the extraction time. The analysis of real wine samples demonstrated the applicability of the method. To our knowledge, this is the first time that VALLME has been applied for the simultaneous determination of haloanisoles and halophenols in wine.

  • Simultaneous determination of Cork Taint and Brett character responsible compounds in wine using ultrasound-assisted emulsification microextraction with solidification of floating organic drop.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this study, ultrasound-assisted emulsification microextraction combined with solidification of floating organic drop method (USAEME–SFOD) has been proposed as a novel approach for the sensitive determination of haloanisoles and volatile phenols in wines. For this purpose, the influence of the different parameters affecting the procedure (type and volume of extraction solvent, temperature, time and ionic strength) was evaluated in order to optimise the efficiency of the process. Subsequently, the linearity, detection and quantification limits, precision, recoveries and applicability to real samples were studied, obtaining excellent method performance results. Moreover, USAEME–SFOD was compared with other liquid–liquid microextraction methods such as dispersive liquid–liquid microextraction (DLLME) and ultrasound-assisted emulsification microextraction (USAEME). This comparison study proved the suitability of USAEME–SFOD as an alternative to previously reported methods for the simultaneous determination of Cork Taint and Brett character responsible compounds in wines.

  • Optimisation of ultrasound-assisted emulsification microextraction method with solidification of floating organic drop for the analysis of Cork Taint responsible compounds in wine.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    This paper presents the optimisation of a method based on ultrasound assisted-emulsification method (USAEME) combined with solidification of floating organic drop (SFOD) for the sensitive determination of Cork Taint responsible compounds in wine. Haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) and their halophenolic precursors were determined by gas chromatography with electron capture detection (GC-ECD). The derivatisation of the halophenols was performed simultaneously with the extraction. To perform the optimisation, the main parameters affecting both extraction and derivatisation were exhaustively studied in different steps. Once the extraction solvent and the pH and time conditions had been determined, experimental design was applied for the simultaneous study of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Then, the analytical characteristics of the optimised method were evaluated achieving satisfactory linearity (with correlation coefficients over 0.984), repeatability (below 10.7%) and inter-day precision (below 10.6%) for all target analytes. Moreover, detection limits found were similar or even lower than the olfactory threshold of the studied compounds. Finally, the applicability of the proposed method was tested by analysing real wine samples. To the best of our knowledge, this is the first time that USAEME-SFOD method has been used to determine Cork Taint responsible compounds in wine.

  • Optimisation of a sensitive method based on ultrasound-assisted emulsification–microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected. Subsequently its volume, the ionic strength and the time and temperature at which the extraction must be performed were simultaneously evaluated by means of experimental design methodology. After optimisation step, the analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.989), repeatability (below 11.5%) and inter-day precision (below 11.7%) were obtained for all target analytes. For all the studied compounds, detection limits obtained were similar or even lower than previously reported. In addition, the developed method was successfully applied to the analysis of wine samples. To the best of our knowledge, this is the first time that USAEME has been applied to simultaneously determine the compounds responsible for Cork Taint and Brett character in wine.

  • Development of an ultrasound-assisted emulsification-microextraction method for the determination of the main compounds causing Cork Taint in wines.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this work, an ultrasound-assisted emulsification–microextraction method has been optimised for the determination in wine of haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) responsible for the so-called Cork Taint. Their halophenolic precursors (2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), 2,4,6-tribromophenol (TBP) and pentachlorophenol (PCP)) have also been simultaneously determined. For this purpose, parameters affecting the USAEME–derivatisation procedure were exhaustively investigated. Firstly, extraction solvent, basic conditions and extraction time were selected to, subsequently, employ experimental design methodology for the simultaneous optimisation of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Once optimised, the evaluation of the analytical performance of the method confirmed its suitability for the determination of the studied compounds in wines. The proposed method showed satisfactory linearity (correlation coefficients over 0.981), repeatability (below 10.9%) and inter-day precision (below 11.0%). Detection limits obtained were similar or even lower than previously reported. In addition, the proposed method was successfully applied to the analysis of real samples. To our knowledge, this is the first time that USAME method has been optimised for the simultaneous determination of haloanisoles and halophenols in wine.

N. Pérez-del-notario - One of the best experts on this subject based on the ideXlab platform.

  • A simple and sensitive vortex assisted liquid-liquid microextraction method for the simultaneous determination of haloanisoles and halophenols in wines.
    Talanta, 2014
    Co-Authors: Consuelo Pizarro, N. Pérez-del-notario, A. Sáenz-mateo, José-maría González-sáiz
    Abstract:

    A vortex assisted liquid-liquid microextraction (VALLME) method was developed and optimised for the determination of the main compounds that can cause Cork Taint in wines, 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA); and their corresponding halophenolic precursors. Target compounds were determined by gas chromatography combined with a micro-electron capture detector (GC-µECD) system. Halophenol extraction and derivatisation processes were performed at the same time. To optimise the VALLME method, the extraction solvent was selected. Then, the other parameters of influence, such as volume of extraction solvent and derivatisation agent, salt addition and vortex time were optimised using a central composite design combined with desirability functions. Once the optimal conditions had been determined, the method was validated, showing satisfactory linearity (with correlation coefficients over 0.983), repeatability (below 10.0%) and reproducibility (below 11.2%). Detection limits obtained were lower than the olfactory threshold of the studied compounds, being similar or even lower than previously reported with the advantage of reducing the extraction time. The analysis of real wine samples demonstrated the applicability of the method. To our knowledge, this is the first time that VALLME has been applied for the simultaneous determination of haloanisoles and halophenols in wine.

  • Simultaneous determination of Cork Taint and Brett character responsible compounds in wine using ultrasound-assisted emulsification microextraction with solidification of floating organic drop.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this study, ultrasound-assisted emulsification microextraction combined with solidification of floating organic drop method (USAEME–SFOD) has been proposed as a novel approach for the sensitive determination of haloanisoles and volatile phenols in wines. For this purpose, the influence of the different parameters affecting the procedure (type and volume of extraction solvent, temperature, time and ionic strength) was evaluated in order to optimise the efficiency of the process. Subsequently, the linearity, detection and quantification limits, precision, recoveries and applicability to real samples were studied, obtaining excellent method performance results. Moreover, USAEME–SFOD was compared with other liquid–liquid microextraction methods such as dispersive liquid–liquid microextraction (DLLME) and ultrasound-assisted emulsification microextraction (USAEME). This comparison study proved the suitability of USAEME–SFOD as an alternative to previously reported methods for the simultaneous determination of Cork Taint and Brett character responsible compounds in wines.

  • Optimisation of ultrasound-assisted emulsification microextraction method with solidification of floating organic drop for the analysis of Cork Taint responsible compounds in wine.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    This paper presents the optimisation of a method based on ultrasound assisted-emulsification method (USAEME) combined with solidification of floating organic drop (SFOD) for the sensitive determination of Cork Taint responsible compounds in wine. Haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) and their halophenolic precursors were determined by gas chromatography with electron capture detection (GC-ECD). The derivatisation of the halophenols was performed simultaneously with the extraction. To perform the optimisation, the main parameters affecting both extraction and derivatisation were exhaustively studied in different steps. Once the extraction solvent and the pH and time conditions had been determined, experimental design was applied for the simultaneous study of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Then, the analytical characteristics of the optimised method were evaluated achieving satisfactory linearity (with correlation coefficients over 0.984), repeatability (below 10.7%) and inter-day precision (below 10.6%) for all target analytes. Moreover, detection limits found were similar or even lower than the olfactory threshold of the studied compounds. Finally, the applicability of the proposed method was tested by analysing real wine samples. To the best of our knowledge, this is the first time that USAEME-SFOD method has been used to determine Cork Taint responsible compounds in wine.

  • Optimisation of a sensitive method based on ultrasound-assisted emulsification–microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected. Subsequently its volume, the ionic strength and the time and temperature at which the extraction must be performed were simultaneously evaluated by means of experimental design methodology. After optimisation step, the analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.989), repeatability (below 11.5%) and inter-day precision (below 11.7%) were obtained for all target analytes. For all the studied compounds, detection limits obtained were similar or even lower than previously reported. In addition, the developed method was successfully applied to the analysis of wine samples. To the best of our knowledge, this is the first time that USAEME has been applied to simultaneously determine the compounds responsible for Cork Taint and Brett character in wine.

  • Development of an ultrasound-assisted emulsification-microextraction method for the determination of the main compounds causing Cork Taint in wines.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this work, an ultrasound-assisted emulsification–microextraction method has been optimised for the determination in wine of haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) responsible for the so-called Cork Taint. Their halophenolic precursors (2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), 2,4,6-tribromophenol (TBP) and pentachlorophenol (PCP)) have also been simultaneously determined. For this purpose, parameters affecting the USAEME–derivatisation procedure were exhaustively investigated. Firstly, extraction solvent, basic conditions and extraction time were selected to, subsequently, employ experimental design methodology for the simultaneous optimisation of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Once optimised, the evaluation of the analytical performance of the method confirmed its suitability for the determination of the studied compounds in wines. The proposed method showed satisfactory linearity (correlation coefficients over 0.981), repeatability (below 10.9%) and inter-day precision (below 11.0%). Detection limits obtained were similar or even lower than previously reported. In addition, the proposed method was successfully applied to the analysis of real samples. To our knowledge, this is the first time that USAME method has been optimised for the simultaneous determination of haloanisoles and halophenols in wine.

C. Sáenz-gonzález - One of the best experts on this subject based on the ideXlab platform.

  • Simultaneous determination of Cork Taint and Brett character responsible compounds in wine using ultrasound-assisted emulsification microextraction with solidification of floating organic drop.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this study, ultrasound-assisted emulsification microextraction combined with solidification of floating organic drop method (USAEME–SFOD) has been proposed as a novel approach for the sensitive determination of haloanisoles and volatile phenols in wines. For this purpose, the influence of the different parameters affecting the procedure (type and volume of extraction solvent, temperature, time and ionic strength) was evaluated in order to optimise the efficiency of the process. Subsequently, the linearity, detection and quantification limits, precision, recoveries and applicability to real samples were studied, obtaining excellent method performance results. Moreover, USAEME–SFOD was compared with other liquid–liquid microextraction methods such as dispersive liquid–liquid microextraction (DLLME) and ultrasound-assisted emulsification microextraction (USAEME). This comparison study proved the suitability of USAEME–SFOD as an alternative to previously reported methods for the simultaneous determination of Cork Taint and Brett character responsible compounds in wines.

  • Microwave assisted extraction combined with dispersive liquid–liquid microextraction as a sensitive sample preparation method for the determination of haloanisoles and halophenols in Cork stoppers and oak barrel sawdust
    Food Chemistry, 2012
    Co-Authors: C Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this paper, a method based on microwave assisted extraction (MAE) in combination with dispersive liquid–liquid microextraction (DLLME) has been proposed as a new approach for the sensitive determination of Cork Taint responsible compounds in Cork stoppers and oak barrel sawdust. For this purpose, haloanisoles and halophenols were extracted from the solid samples using a MAE method. Subsequently, a DLLME-derivatisation procedure was applied on the MAE extracts and the analytes were determined by gas chromatography–electron capture detection (GC–ECD). Parameters affecting the DLLME-derivatisation method were exhaustively investigated by means of experimental design methodology. Once optimised, the proposed method showed satisfactory linearity (correlation coefficients over 0.991), repeatability (below 10.4%) and inter-day precision (below 11.2%). Detection limits obtained were similar or even lower than previously reported. The results obtained proved the suitability of the combination of MAE with DLLME as a sensitive sample preparation methodology for the analysis of haloanisoles and halophenols in solid enological matrices.

  • Optimisation of ultrasound-assisted emulsification microextraction method with solidification of floating organic drop for the analysis of Cork Taint responsible compounds in wine.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    This paper presents the optimisation of a method based on ultrasound assisted-emulsification method (USAEME) combined with solidification of floating organic drop (SFOD) for the sensitive determination of Cork Taint responsible compounds in wine. Haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) and their halophenolic precursors were determined by gas chromatography with electron capture detection (GC-ECD). The derivatisation of the halophenols was performed simultaneously with the extraction. To perform the optimisation, the main parameters affecting both extraction and derivatisation were exhaustively studied in different steps. Once the extraction solvent and the pH and time conditions had been determined, experimental design was applied for the simultaneous study of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Then, the analytical characteristics of the optimised method were evaluated achieving satisfactory linearity (with correlation coefficients over 0.984), repeatability (below 10.7%) and inter-day precision (below 10.6%) for all target analytes. Moreover, detection limits found were similar or even lower than the olfactory threshold of the studied compounds. Finally, the applicability of the proposed method was tested by analysing real wine samples. To the best of our knowledge, this is the first time that USAEME-SFOD method has been used to determine Cork Taint responsible compounds in wine.

  • Optimisation of a sensitive method based on ultrasound-assisted emulsification–microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected. Subsequently its volume, the ionic strength and the time and temperature at which the extraction must be performed were simultaneously evaluated by means of experimental design methodology. After optimisation step, the analytical characteristics of the method were evaluated. Satisfactory linearity (with correlation coefficients over 0.989), repeatability (below 11.5%) and inter-day precision (below 11.7%) were obtained for all target analytes. For all the studied compounds, detection limits obtained were similar or even lower than previously reported. In addition, the developed method was successfully applied to the analysis of wine samples. To the best of our knowledge, this is the first time that USAEME has been applied to simultaneously determine the compounds responsible for Cork Taint and Brett character in wine.

  • Development of an ultrasound-assisted emulsification-microextraction method for the determination of the main compounds causing Cork Taint in wines.
    Journal of chromatography. A, 2012
    Co-Authors: Consuelo Pizarro, C. Sáenz-gonzález, N. Pérez-del-notario, José-maría González-sáiz
    Abstract:

    Abstract In this work, an ultrasound-assisted emulsification–microextraction method has been optimised for the determination in wine of haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) responsible for the so-called Cork Taint. Their halophenolic precursors (2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), 2,4,6-tribromophenol (TBP) and pentachlorophenol (PCP)) have also been simultaneously determined. For this purpose, parameters affecting the USAEME–derivatisation procedure were exhaustively investigated. Firstly, extraction solvent, basic conditions and extraction time were selected to, subsequently, employ experimental design methodology for the simultaneous optimisation of the volumes of acetic anhydride and extraction solvent, temperature and ionic strength conditions. Once optimised, the evaluation of the analytical performance of the method confirmed its suitability for the determination of the studied compounds in wines. The proposed method showed satisfactory linearity (correlation coefficients over 0.981), repeatability (below 10.9%) and inter-day precision (below 11.0%). Detection limits obtained were similar or even lower than previously reported. In addition, the proposed method was successfully applied to the analysis of real samples. To our knowledge, this is the first time that USAME method has been optimised for the simultaneous determination of haloanisoles and halophenols in wine.

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  • role of chrysonilia sitophila in the quality of Cork stoppers for sealing wine bottles
    Journal of Industrial Microbiology & Biotechnology, 2000
    Co-Authors: Silva C Pereira, J Figueiredo J Marques, Antero Pires, M J Valle, Vilas L Boas, M San V Romao
    Abstract:

    The contribution of Chrysonilia sitophila in Cork stopper manufacture was studied and a simulation of the industrial processing of Cork stoppers was performed. Stoppers cut from slabs where mold development was inhibited were compared with others cut from slabs colonized by C. sitophila alone or with several molds, in terms of physical properties and chemical Taints. C. sitophila does not produce 2,4,6-trichloroanisole, guaiacol, or 1-octene-3-ol on Cork slabs incubated for 66 days. Since some chlorophenol-related compounds contaminate Cork slabs during the production processes, metabolic tests were performed to investigate the capability of molds to produce 2,4,6-trichloroanisole by methylation of 2,4,6-trichlorophenol. Degradation of 2,4,6-trichlorophenol by C. sitophila resulted in a very high level of degradation without production of 2,4,6-trichloroanisole. C. sitophila restricted growth of other molds on maturing slabs for at least 30 days. These results show that C. sitophila can be exploited by industrial producers of Cork stoppers since it is able to inhibit the development of other molds and it does not produce the compounds responsible for ‘Cork-Taint’, even in the presence of chlorophenols. Journal of Industrial Microbiology & Biotechnology (2000) 24, 256–261.

  • Cork Taint in wine scientific knowledge and public perception a critical review
    Critical Reviews in Microbiology, 2000
    Co-Authors: Silva C Pereira, J Figueiredo J Marques, M San V Romao
    Abstract:

    The manufacturing process of Cork stoppers includes a stabilization period of the Cork slabs, following boiling, during which mold growth completely covers the Cork slabs. This process has been used traditionally for several decades; however, due to the possibility of certain molds isolated from Cork to produce off flavor compounds, especially 2,4,6-trichloroanisole and 2,3,4,6-tetrachloroanisole, recently Cork stoppers are being unsoundly targeted with the accusation of inducing Cork Taint in wine. This article reviews the manufacturing process of Cork stoppers, the diversity of microorganisms associated with Cork, and finally the diversity and origins of the compounds associated with Cork Taint in wine, focusing on those currently considered as more important. Some important results recently obtained by the authors are also included. The current idea of suppressing mold growth during Cork stopper manufacturing is discussed, as well as the erroneous idea of imputing, directly and exclusively, to Cork the responsibility of the so-called Cork Taint in wine.

  • mycobiota in portuguese normal and green Cork throughout the manufacturing process of stoppers
    Journal of Applied Microbiology, 1997
    Co-Authors: P Danesh, F Velez M Caldas, J Figueiredo J Marques, M San V Romao
    Abstract:

    The compounds responsible for the so-called ‘Cork Taint’ include, among others, some microbial metabolites which can be produced by the microbial population colonizing the unprocessed Cork and stoppers. This study was intended to obtain information on the mycobiota associated with Portuguese Cork throughout the manufacturing process of stoppers. Samples of barks and stoppers of both ‘normal’ and ‘green’ Cork were examined. Moulds were isolated from ‘normal’ and ‘green’ Cork throughout the entire Cork stopper manufacturing process. Yeasts were rarely detected in the Corks. Fungal contamination was not detected in finished stoppers from the company under study.