The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform
M T Galceran - One of the best experts on this subject based on the ideXlab platform.
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Comparison of dimethylformamide dialkylacetal derivatization reagents for the analysis of heterocyclic amines in Meat Extracts by gas chromatography–mass spectrometry
Analytica Chimica Acta, 2005Co-Authors: E Barceló-barrachina, F J Santos, Lluis Puignou, M T GalceranAbstract:Abstract A simple and selective methodology for the analysis of heterocyclic amines (HAs) in a Meat extract by gas chromatography–mass spectrometry (GC–MS) is proposed. A comparative study of several HAs derivatization procedures based on the formation of Schiff bases using N,N-dimethylformamide dialkylacetals reagents was performed. Optimization of the reaction conditions was carried out, such as reagent volume (2 μl to derivatize 1 ng of HAs) temperature (100 °C) and time (10 min). After that, the GC–MS working parameters for the analysis of HAs derivatives were also studied in order to achieve the best chromatographic separation with the maximum sensitivity. Among the derivatization reagents, N,N-dimethylformamide di-tert-butylacetal (DMF-DtBA) was selected because it provided the best yield in the derivatization process, and consequently the best sensitivity in the GC–MS method. Quality parameters such as limits of detection and repeatability were established using a Meat extract sample. A complete validation of the methodology was achieved using a laboratory reference material previously analyzed in a European interlaboratory exercise.
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comparison of dimethylformamide dialkylacetal derivatization reagents for the analysis of heterocyclic amines in Meat Extracts by gas chromatography mass spectrometry
Analytica Chimica Acta, 2005Co-Authors: E Barcelobarrachina, L Puignou, F J Santos, M T GalceranAbstract:Abstract A simple and selective methodology for the analysis of heterocyclic amines (HAs) in a Meat extract by gas chromatography–mass spectrometry (GC–MS) is proposed. A comparative study of several HAs derivatization procedures based on the formation of Schiff bases using N,N-dimethylformamide dialkylacetals reagents was performed. Optimization of the reaction conditions was carried out, such as reagent volume (2 μl to derivatize 1 ng of HAs) temperature (100 °C) and time (10 min). After that, the GC–MS working parameters for the analysis of HAs derivatives were also studied in order to achieve the best chromatographic separation with the maximum sensitivity. Among the derivatization reagents, N,N-dimethylformamide di-tert-butylacetal (DMF-DtBA) was selected because it provided the best yield in the derivatization process, and consequently the best sensitivity in the GC–MS method. Quality parameters such as limits of detection and repeatability were established using a Meat extract sample. A complete validation of the methodology was achieved using a laboratory reference material previously analyzed in a European interlaboratory exercise.
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determination of heterocyclic aromatic amines in Meat Extracts by liquid chromatography ion trap atmospheric pressure chemical ionization mass spectrometry
Journal of Chromatography A, 2000Co-Authors: F Toribio, E Moyano, L Puignou, M T GalceranAbstract:Abstract When protein-rich foods are processed under normal cooking conditions, heterocyclic aromatic amines (HAAs) can be generated at a few parts per billion level. In this work, we have analyzed the HAAs present in a lyophilized Meat extract by means of a simplified solid-phase extraction procedure. All the analytes were collected in a single extract with recoveries in the range of 45.6–75.2%, so the analysis time has been greatly reduced. Problems derived from the less exhaustive purification of the extract have been solved by using MS(ion trap) detection. The RSD for quantification ranged from 2.1% to 5.1% for run-to-run precision and from 5.2% to 11% for day-to-day precision. The limits of detection for standard solutions ranged from 20 to 150 pg injected. For the Meat extract analyzed limits of detection from 0.9 to 11.2 ng g −1 were obtained. Results of the quantification are in agreement with those obtained using different clean-up procedures.
Ana M Afonso - One of the best experts on this subject based on the ideXlab platform.
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Focused Microwave‐Assisted Extraction and HPLC with Electrochemical Detection to Determine Heterocyclic Amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2020Co-Authors: Aurora Martín-calero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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focused microwave assisted extraction and hplc with electrochemical detection to determine heterocyclic amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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determination of less polar heterocyclic amines in Meat Extracts fast sample preparation method using solid phase microextraction prior to high performance liquid chromatography fluorescence quantification
Analytica Chimica Acta, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Ana M AfonsoAbstract:Abstract A procedure for the determination of less polar heterocyclic amines in Meat Extracts using solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) with fluorescence detection is presented. Analytes were first extracted from the samples using methanol/NaOH by an ultrasound-assisted method, and then concentrated on a Carbowax-templated resin (CW-TPR) SPME fiber. The extraction conditions such as extractant mixture composition, extraction time and extractions number, were optimized and the need of an extract freezing step previous to SPME is discussed. The detection limits under optimal conditions are in the range of 0.28–1.1 ng g−1. The method was applied to the determination of less polar heterocyclic amines in four commercial Meat Extracts. Recovery values obtained are higher than 60% for the majority of amines.
Juan H. Ayala - One of the best experts on this subject based on the ideXlab platform.
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Focused Microwave‐Assisted Extraction and HPLC with Electrochemical Detection to Determine Heterocyclic Amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2020Co-Authors: Aurora Martín-calero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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focused microwave assisted extraction and hplc with electrochemical detection to determine heterocyclic amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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determination of less polar heterocyclic amines in Meat Extracts fast sample preparation method using solid phase microextraction prior to high performance liquid chromatography fluorescence quantification
Analytica Chimica Acta, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Ana M AfonsoAbstract:Abstract A procedure for the determination of less polar heterocyclic amines in Meat Extracts using solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) with fluorescence detection is presented. Analytes were first extracted from the samples using methanol/NaOH by an ultrasound-assisted method, and then concentrated on a Carbowax-templated resin (CW-TPR) SPME fiber. The extraction conditions such as extractant mixture composition, extraction time and extractions number, were optimized and the need of an extract freezing step previous to SPME is discussed. The detection limits under optimal conditions are in the range of 0.28–1.1 ng g−1. The method was applied to the determination of less polar heterocyclic amines in four commercial Meat Extracts. Recovery values obtained are higher than 60% for the majority of amines.
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Determination of less polar heterocyclic amines in Meat Extracts. Fast sample preparation method using solid-phase microextraction prior to high-performance liquid chromatography-fluorescence quantification
Analytica Chimica Acta, 2007Co-Authors: Aurora Martín-calero, Juan H. Ayala, Venerando González, Anna M. AfonsoAbstract:A procedure for the determination of less polar heterocyclic amines in Meat Extracts using solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) with fluorescence detection is presented. Analytes were first extracted from the samples using methanol/NaOH by an ultrasound-assisted method, and then concentrated on a Carbowax-templated resin (CW-TPR) SPME fiber. The extraction conditions such as extractant mixture composition, extraction time and extractions number, were optimized and the need of an extract freezing step previous to SPME is discussed. The detection limits under optimal conditions are in the range of 0.28-1.1 ng g-1. The method was applied to the determination of less polar heterocyclic amines in four commercial Meat Extracts. Recovery values obtained are higher than 60% for the majority of amines. ?? 2006 Elsevier B.V. All rights reserved.
Venerando González - One of the best experts on this subject based on the ideXlab platform.
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Focused Microwave‐Assisted Extraction and HPLC with Electrochemical Detection to Determine Heterocyclic Amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2020Co-Authors: Aurora Martín-calero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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focused microwave assisted extraction and hplc with electrochemical detection to determine heterocyclic amines in Meat Extracts
Journal of Liquid Chromatography & Related Technologies, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Veronica Pino, Ana M AfonsoAbstract:Abstract A method for the determination of 11 heterocyclic amines (HAs) in Meat Extracts by high performance liquid chromatography with electrochemical detection is proposed. The chromatographic method is optimized to obtain both polar and less polar amines in the same chromatographic run, which is a difficult task when using electrochemical detection. The extraction of the Meat Extracts is carried out using a focused microwave system, a technique applied for first‐time in the extraction of these analytes. The microwave extraction process takes only 5 minutes, an improvement on the extraction times for methods commonly applied to heterocyclic amines in food samples. This screening method allows us to determine HAs in Meat Extracts with average recoveries of 81.2%, 76.4%, 66.7%, 60.3%, and 63.8%, for granulated Meat extract, non‐granulated Meat extract, chicken extract, and soup cubes (brands A and B), respectively. The proposed method has an intermediate precision ranging from 6.1 to 12.8%, and detection ...
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determination of less polar heterocyclic amines in Meat Extracts fast sample preparation method using solid phase microextraction prior to high performance liquid chromatography fluorescence quantification
Analytica Chimica Acta, 2007Co-Authors: Aurora Martincalero, Juan H. Ayala, Venerando González, Ana M AfonsoAbstract:Abstract A procedure for the determination of less polar heterocyclic amines in Meat Extracts using solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) with fluorescence detection is presented. Analytes were first extracted from the samples using methanol/NaOH by an ultrasound-assisted method, and then concentrated on a Carbowax-templated resin (CW-TPR) SPME fiber. The extraction conditions such as extractant mixture composition, extraction time and extractions number, were optimized and the need of an extract freezing step previous to SPME is discussed. The detection limits under optimal conditions are in the range of 0.28–1.1 ng g−1. The method was applied to the determination of less polar heterocyclic amines in four commercial Meat Extracts. Recovery values obtained are higher than 60% for the majority of amines.
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Determination of less polar heterocyclic amines in Meat Extracts. Fast sample preparation method using solid-phase microextraction prior to high-performance liquid chromatography-fluorescence quantification
Analytica Chimica Acta, 2007Co-Authors: Aurora Martín-calero, Juan H. Ayala, Venerando González, Anna M. AfonsoAbstract:A procedure for the determination of less polar heterocyclic amines in Meat Extracts using solid phase microextraction (SPME) coupled to high-performance liquid chromatography (HPLC) with fluorescence detection is presented. Analytes were first extracted from the samples using methanol/NaOH by an ultrasound-assisted method, and then concentrated on a Carbowax-templated resin (CW-TPR) SPME fiber. The extraction conditions such as extractant mixture composition, extraction time and extractions number, were optimized and the need of an extract freezing step previous to SPME is discussed. The detection limits under optimal conditions are in the range of 0.28-1.1 ng g-1. The method was applied to the determination of less polar heterocyclic amines in four commercial Meat Extracts. Recovery values obtained are higher than 60% for the majority of amines. ?? 2006 Elsevier B.V. All rights reserved.
L Puignou - One of the best experts on this subject based on the ideXlab platform.
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new method for the analysis of heterocyclic amines in Meat Extracts using pressurised liquid extraction and liquid chromatography tandem mass spectrometry
Journal of Chromatography A, 2008Co-Authors: Mohammad Rizwan Khan, F J Santos, Rosa Busquets, L PuignouAbstract:Heterocyclic amines (HAs) were analysed in Meat extract samples using a new method based on pressurised liquid extraction (PLE) and liquid chromatography-tandem mass spectrometry. This method combines the use of a pressurised fluid with a triple quadrupole MS/MS system, resulting in benefits from both systems: high extraction efficiency and sensitivity. The effects of solvent type and PLE operational parameters, such as temperature and extraction time, were studied to obtain maximum recovery of the analytes with minimum contamination. HA extraction was best achieved using dichloromethane/acetone (50/50, v/v) at 80 degrees C for 10 min. Recoveries ranged from 45% to 79% with good quality parameters: limit of detection values between 0.02 and 1 ng g(-1), linearity (r(2)>0.997), and run-to-run and day-to-day precisions with relative standard deviations lower than 13% achieved at both low (0.20 microg g(-1)) and medium (1.0 microg g(-1)) concentrations. This method reduces sample manipulation and total extraction time by nearly four-fold compared to conventional solid phase extraction. The optimised method was validated using laboratory reference material based on a Meat extract, and was successfully applied to HA analysis in several cooked beef samples.
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comparison of dimethylformamide dialkylacetal derivatization reagents for the analysis of heterocyclic amines in Meat Extracts by gas chromatography mass spectrometry
Analytica Chimica Acta, 2005Co-Authors: E Barcelobarrachina, L Puignou, F J Santos, M T GalceranAbstract:Abstract A simple and selective methodology for the analysis of heterocyclic amines (HAs) in a Meat extract by gas chromatography–mass spectrometry (GC–MS) is proposed. A comparative study of several HAs derivatization procedures based on the formation of Schiff bases using N,N-dimethylformamide dialkylacetals reagents was performed. Optimization of the reaction conditions was carried out, such as reagent volume (2 μl to derivatize 1 ng of HAs) temperature (100 °C) and time (10 min). After that, the GC–MS working parameters for the analysis of HAs derivatives were also studied in order to achieve the best chromatographic separation with the maximum sensitivity. Among the derivatization reagents, N,N-dimethylformamide di-tert-butylacetal (DMF-DtBA) was selected because it provided the best yield in the derivatization process, and consequently the best sensitivity in the GC–MS method. Quality parameters such as limits of detection and repeatability were established using a Meat extract sample. A complete validation of the methodology was achieved using a laboratory reference material previously analyzed in a European interlaboratory exercise.
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determination of heterocyclic aromatic amines in Meat Extracts by liquid chromatography ion trap atmospheric pressure chemical ionization mass spectrometry
Journal of Chromatography A, 2000Co-Authors: F Toribio, E Moyano, L Puignou, M T GalceranAbstract:Abstract When protein-rich foods are processed under normal cooking conditions, heterocyclic aromatic amines (HAAs) can be generated at a few parts per billion level. In this work, we have analyzed the HAAs present in a lyophilized Meat extract by means of a simplified solid-phase extraction procedure. All the analytes were collected in a single extract with recoveries in the range of 45.6–75.2%, so the analysis time has been greatly reduced. Problems derived from the less exhaustive purification of the extract have been solved by using MS(ion trap) detection. The RSD for quantification ranged from 2.1% to 5.1% for run-to-run precision and from 5.2% to 11% for day-to-day precision. The limits of detection for standard solutions ranged from 20 to 150 pg injected. For the Meat extract analyzed limits of detection from 0.9 to 11.2 ng g −1 were obtained. Results of the quantification are in agreement with those obtained using different clean-up procedures.