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Yolanda Picó - One of the best experts on this subject based on the ideXlab platform.

  • Pressurized Liquid Extraction of Organic Contaminants in Environmental and Food Samples
    TrAC Trends in Analytical Chemistry, 2015
    Co-Authors: Pablo Vázquez-roig, Yolanda Picó
    Abstract:

    Abstract Pressurized Liquid Extraction (PLE) is an automated technique that uses elevated temperature and pressure to achieve exhaustive Extraction from solid matrices, so reducing solvent consumption and enhancing sample throughput when compared with traditional procedures. Hence, it can be considered an environment-friendly technique, generating small volumes of waste and reducing costs and time. This review focuses on application of this green technique to the analysis of organic contaminants in food and environmental matrices for monitoring purposes. We examine fundamentals and key aspects of the development of a PLE method, including Pressurized hot-water Extraction, together with some relevant applications in food and the environment. We pay special attention to methods, including clean-up in one step in the Extraction cell or on-line clean-up coupled to the Extraction cell. We also compare PLE with other techniques (e.g., Soxhlet, microwave-assisted Extraction, and supercritical fluid Extraction).

  • determination of benzoylurea insecticides in food by Pressurized Liquid Extraction and lc ms
    Analytical Abstracts, 2010
    Co-Authors: Monia Brutti, Cristina Blasco, Yolanda Picó
    Abstract:

    A method based on Pressurized Liquid Extraction and LC-MS/MS has been developed for determining nine benzoylureas (BUs) in fruit, vegetable, cereals, and animal products. Samples (5 g) were homogenized with diatomaceous earth and extracted in a 22 mL cell with 22 mL of ethyl acetate at 80°C and 1500 psi. After solvent concentration and exchange to methanol, BUs were analyzed by LC-MS/MS using an IT mass analyzer, which achieved several transitions of precursor ions that increase selectivity providing identification. LOQs were between 0.002 and 0.01 mg/kg, which are equal or lower than maximum residue limits established by the Codex Alimentarius. Excellent linearity was achieved over a range of concentrations from 0.01 to 1 mg/kg with correlation coefficients 0.995-0.999 (n = 7). Validation of the total method was performed by analyzing in quintuplicate seven different commodities (milk, eggs, meat, rice, lettuce, avocado, and lemon) at three concentration levels (0.01, 0.1, and 1 mg/kg). The recoveries ranged from 58 to 97% and the RSDs from 5 to 19% depending on the compound and the commodity. The combination of Pressurized Liquid Extraction with LC-MS/MS provides a sensitive and selective method for the determination of BUs in food.

  • determination of benzoylurea insecticides in food by Pressurized Liquid Extraction and lc ms
    Journal of Separation Science, 2010
    Co-Authors: Monia Brutti, Cristina Blasco, Yolanda Picó
    Abstract:

    A method based on Pressurized Liquid Extraction and LC-MS/MS has been developed for determining nine benzoylureas (BUs) in fruit, vegetable, cereals, and animal products. Samples (5 g) were homogenized with diatomaceous earth and extracted in a 22 mL cell with 22 mL of ethyl acetate at 80 degrees C and 1500 psi. After solvent concentration and exchange to methanol, BUs were analyzed by LC-MS/MS using an IT mass analyzer, which achieved several transitions of precursor ions that increase selectivity providing identification. LOQs were between 0.002 and 0.01 mg/kg, which are equal or lower than maximum residue limits established by the Codex Alimentarius. Excellent linearity was achieved over a range of concentrations from 0.01 to 1 mg/kg with correlation coefficients 0.995-0.999 (n=7). Validation of the total method was performed by analyzing in quintuplicate seven different commodities (milk, eggs, meat, rice, lettuce, avocado, and lemon) at three concentration levels (0.01, 0.1, and 1 mg/kg). The recoveries ranged from 58 to 97% and the RSDs from 5 to 19% depending on the compound and the commodity. The combination of Pressurized Liquid Extraction with LC-MS/MS provides a sensitive and selective method for the determination of BUs in food.

  • determination of isopropyl thioxanthone itx in fruit juices by Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Agricultural and Food Chemistry, 2006
    Co-Authors: Gianni Sagratini, Jordi Manes, Dario Giardina, Yolanda Picó
    Abstract:

    A rapid LC-MS method, which compares different mass analyzerssingle quadrupole, ion trap, and triple quadrupolewas developed for the quantitative determination of isopropyl thioxanthone (ITX) in fruit juices. ITX, a photoinitiator in UV-cured inks that can reach foods from the cartons for beverages in which they are used, was extracted from fruit juice samples with acetone/hexane (50:50) using Pressurized Liquid Extraction. This method gave detection limits of 3, 3, and 0.01 μg/L and quantification limits of 10, 10, and 0.05 μg/L using single quadrupole, ion trap, and triple quadrupole, respectively. Five replicate fortifications of different fruit juices at the quantification limit gave recoveries oscillating between 68 and 72% with CV varying between 14 and 18%. This is the first report of a positive mass spectrometric identification and quantification of ITX in fruit juice samples packed in TetraPack. The sensitivity and specificity of the LC-MS/MS analysis using the triple quadrupole enables it to be ...

  • analysis of pesticides in fruits by Pressurized Liquid Extraction and Liquid chromatography ion trap triple stage mass spectrometry
    Journal of Chromatography A, 2005
    Co-Authors: Cristina Blasco, Gabriel Font, Yolanda Picó
    Abstract:

    A multi-residue method using Pressurized Liquid Extraction (PLE) and Liquid chromatography-quadrupole ion trap-triple stage mass spectrometry (LC-IT-MS(3)) has been developed for determining trace levels of pesticides in fruits. The selected pesticides can be distinguished in: benzimidazoles and azoles, organophosphorus, carbamates, neonicotinoids, and acaricides. PLE has been optimized to extract these pesticide residues from oranges and peaches by studying the effect of experimental variables on PLE efficiency. Samples were extracted at high temperature and pressure (75 degrees C and 1500psi) using ethyl acetate as Extraction solvent and acidic alumina as drying agent. The recoveries obtained by PLE ranged from 58% to 97% and the relative standard deviation (RSDs) from 5% to 19%. The limits of quantification (LOQs) of the compounds were from 0.025 to 0.25mgkg(-1), which are well-below the maximum residue limits (MRLs) established by the European Union (EU) and the Spanish legislations.

Rosa Maria Marcé - One of the best experts on this subject based on the ideXlab platform.

  • Pressurized Liquid Extraction a useful technique to extract pharmaceuticals and personal care products from sewage sludge
    Trends in Analytical Chemistry, 2010
    Co-Authors: Antonio Nieto, Francesc Borrull, Eva Pocurull, Rosa Maria Marcé
    Abstract:

    We review the determination of pharmaceuticals and personal-care products (PPCPs) in sewage-sludge samples using Pressurized Liquid Extraction (PLE). PLE is a sample-preparation technique that is increasingly used to extract moderately volatile and non-volatile organic contaminants from solid samples. We discuss the principal parameters to be optimized in PLE (e.g., solvent Extraction, temperature, pressure and Extraction time). We also examine the occurrence of PPCPs in studies where PLE is applied to sewage sludge.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

  • Pressurized Liquid Extraction of pharmaceuticals from sewage sludge
    Journal of Separation Science, 2007
    Co-Authors: Antonio Nieto, Francesc Borrull, Eva Pocurull, Rosa Maria Marcé
    Abstract:

    A method for the quantitative determination of ten pharmaceuticals in sewage sludge was developed by using Pressurized Liquid Extraction (PLE) and HPLC–MS with ESI (HPLC-(ESI)MS). The PLE was optimized with regard to solvents and operational parameters, such as temperature, pressure, Extraction time, and purge time. The optimum conditions were: 50 mM phosphoric acid/methanol (1:1 v/v) as the Extraction solvent, temperature of 100°C, pressure of 100 bar, Extraction time 15 min, 2 cycles, flush volume 150% and purge time 300 s. All recoveries for pharmaceuticals were over 68% except for salicylic acid. The repetitivity and reproducibility between days expressed as RSD was lower than 8% for repetitivity and 10% for reproducibility. The LOD of all compounds was lower than 10 μg/kg of dry weight of sewage sludge. The method was applied to determine the pharmaceuticals in sewage sludge from two domestic sewage treatment plants (STPs). The samples were collected every three months between February 2004 and June 2005. Some pharmaceuticals were determined in the samples and naproxen showed the highest value (242 μg/kg of dry weight).

Gabriel Font - One of the best experts on this subject based on the ideXlab platform.

  • determination of aminoglycoside and macrolide antibiotics in meat by Pressurized Liquid Extraction and lc esi ms
    IEEE Journal of Solid-state Circuits, 2010
    Co-Authors: Houda Berrada, J C Molto, Jordi Manes, Gabriel Font
    Abstract:

    : A simple method for the simultaneous determination of dihydrostreptomycin, spectinomycin, spiramycin, streptomycin, tilmicosin, and tylosin in meat has been developed using Pressurized Liquid Extraction and LC-triple quadrupole MS (LC-ESI-MS/MS). The Pressurized Liquid Extraction operational parameters were optimized and no protein precipitating and fat removing steps were required. A gradient HPLC separation was developed with ion-pair mobile phases consisting of aqueous 1 mM heptafluorobutyric acid water and methanol. Protonated molecules were used as precursor ions for CID. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of three fragment ion transitions to provide a high degree of sensitivity and specificity. Dirithromycin and sisomycin were selected as internal standards. A validation study was conducted for these antibiotics in poultry meat samples. All selected compounds could be detected (monitoring ions by multiple reaction monitoring) in meat samples at amounts below the regulatory level of concern. Using the internal standards, Pressurized Liquid Extraction recovery rates were from 70 to 96% (RSD 12-25%). LC-ESI-MS/MS method detection limits of the selected antibiotics were 1-6 microg/kg. Good method reproducibility was found by intra- and inter-day precisions at maximum residue level, yielding the RSDs less than 15 and 16%, respectively.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

  • analysis of pesticides in fruits by Pressurized Liquid Extraction and Liquid chromatography ion trap triple stage mass spectrometry
    Journal of Chromatography A, 2005
    Co-Authors: Cristina Blasco, Gabriel Font, Yolanda Picó
    Abstract:

    A multi-residue method using Pressurized Liquid Extraction (PLE) and Liquid chromatography-quadrupole ion trap-triple stage mass spectrometry (LC-IT-MS(3)) has been developed for determining trace levels of pesticides in fruits. The selected pesticides can be distinguished in: benzimidazoles and azoles, organophosphorus, carbamates, neonicotinoids, and acaricides. PLE has been optimized to extract these pesticide residues from oranges and peaches by studying the effect of experimental variables on PLE efficiency. Samples were extracted at high temperature and pressure (75 degrees C and 1500psi) using ethyl acetate as Extraction solvent and acidic alumina as drying agent. The recoveries obtained by PLE ranged from 58% to 97% and the relative standard deviation (RSDs) from 5% to 19%. The limits of quantification (LOQs) of the compounds were from 0.025 to 0.25mgkg(-1), which are well-below the maximum residue limits (MRLs) established by the European Union (EU) and the Spanish legislations.

Houda Berrada - One of the best experts on this subject based on the ideXlab platform.

  • determination of aminoglycoside and macrolide antibiotics in meat by Pressurized Liquid Extraction and lc esi ms
    IEEE Journal of Solid-state Circuits, 2010
    Co-Authors: Houda Berrada, J C Molto, Jordi Manes, Gabriel Font
    Abstract:

    : A simple method for the simultaneous determination of dihydrostreptomycin, spectinomycin, spiramycin, streptomycin, tilmicosin, and tylosin in meat has been developed using Pressurized Liquid Extraction and LC-triple quadrupole MS (LC-ESI-MS/MS). The Pressurized Liquid Extraction operational parameters were optimized and no protein precipitating and fat removing steps were required. A gradient HPLC separation was developed with ion-pair mobile phases consisting of aqueous 1 mM heptafluorobutyric acid water and methanol. Protonated molecules were used as precursor ions for CID. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring of three fragment ion transitions to provide a high degree of sensitivity and specificity. Dirithromycin and sisomycin were selected as internal standards. A validation study was conducted for these antibiotics in poultry meat samples. All selected compounds could be detected (monitoring ions by multiple reaction monitoring) in meat samples at amounts below the regulatory level of concern. Using the internal standards, Pressurized Liquid Extraction recovery rates were from 70 to 96% (RSD 12-25%). LC-ESI-MS/MS method detection limits of the selected antibiotics were 1-6 microg/kg. Good method reproducibility was found by intra- and inter-day precisions at maximum residue level, yielding the RSDs less than 15 and 16%, respectively.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

  • determination of macrolide antibiotics in meat and fish using Pressurized Liquid Extraction and Liquid chromatography mass spectrometry
    Journal of Chromatography A, 2008
    Co-Authors: Houda Berrada, Gabriel Font, Francesc Borrull, Rosa Maria Marcé
    Abstract:

    Abstract We developed a method for determining the quantities of seven macrolide antibiotics in meat and fish by using Pressurized Liquid Extraction (PLE) and Liquid chromatography–mass spectrometry with electrospray ionization (LC–(ESI)MS). The PLE was optimized with regard to solvents, temperature, pressure, Extraction time and number of cycles. The optimum conditions were: methanol as the Extraction solvent; a temperature of 80 °C; a pressure of 1500 psi; an Extraction time of 15 min; 2 cycles; a flush volume of 150% and a purge time of 300 s. All recoveries for macrolide antibiotics were over 77% at 200 μg/kg, except for erythromycin, which was 58%. The repeatability and reproducibility on days in between, expressed as %RSD (n = 12), were lower than 10% and 12%, respectively. The quantification limits of all compounds were 25 μg/kg of dry weight of animal muscle except for troleandomycin (50 μg/kg). The method was applied to determine the pharmaceuticals in real samples taken from 18 meat and fish samples. The results showed that PLE is quantitative short time consuming technique, with use of smaller initial sample sizes. Greater specificity and selectivity in Extraction and increased potential for automation were shown.

Eng Shi Ong - One of the best experts on this subject based on the ideXlab platform.

  • chemical assay of glycyrrhizin in medicinal plants by Pressurized Liquid Extraction ple with capillary zone electrophoresis cze
    Journal of Separation Science, 2002
    Co-Authors: Eng Shi Ong
    Abstract:

    Glycyrrhizin in Radix glycyrrhizae or liquorice was determined using a laboratory made dynamic Pressurized Liquid Extraction (PLE) system coupled with capillary zone electrophoresis (CZE). The amount of glycyrrhizin was determined using CZE with an aqueous buffer of 10 mM of sodium tetraborate at pH 9.25 with UV detection at 254 nm. The effects of pH, buffer concentration, and the applied voltage on the electrophoretic separation were investigated. Temperature was found to be the important parameter in PLE as it was observed that the amount of thermally labile components such as glycyrrhizin extracted from medicinal plants decreased with increasing temperature from 100 to 160°C. The amount of glycyrrhizin extracted by PLE with methanol as solvent for glycyrrhizin in medicinal plants was found to be comparable or higher compared to multiple step ultrasonic Extraction using a mixture of methanol/ water (70:30). The overall method precision was found to vary from 6.9 to 8.1% (RSD) for glycyrrhizin in medicinal plants. The specificity of the method was checked using standard addition experiments.

  • determination of berberine and strychnine in medicinal plants and herbal preparations by Pressurized Liquid Extraction with capillary zone electrophoresis
    Electrophoresis, 2001
    Co-Authors: Eng Shi Ong, Siti Norasikin Binte Apandi
    Abstract:

    A simple and rapid method for the determination of berberine and strychnine in medicinal plants and herbal preparations for regulatory purposes using a home-made Pressurized Liquid Extraction (PLE) system with capillary zone electrophoresis (CZE) using ultraviolet detection at 254 nm was developed. The effects of pH, concentration of buffer, and organic modifiers in the electrophoretic separation were investigated. The buffer used for CZE contained 50 mM ammonium acetate, pH 3.1. The effect of temperature on the Extraction efficiency of strychnine in medicinal plants by PLE was demonstrated. Comparable or higher Extraction efficiency was achieved with PLE for strychnine in medicinal plants and berberine in herbal preparations compared to soxhlet Extraction. The effect of matrix interference in medicinal plants and herbal preparations containing a number of medicinal plants samples using CZE was investigated by standard additional experiments. The reproducibility of the method using PLE with CZE was found to vary between 2.4 and 10.7% (n = 5/6) for different types of samples on different days.

  • Pressurized Liquid Extraction of berberine and aristolochic acids in medicinal plants
    Journal of chromatography. A, 2000
    Co-Authors: Eng Shi Ong, Soo-on Woo, Yuk-lin Yong
    Abstract:

    Berberine and aristolochic acids I and II present naturally in medicinal plants were extracted using a laboratory-made Pressurized Liquid Extraction (PLE) system in the dynamic mode. As the target analytes were present naturally in the medicinal plants, spiking was not done and comparison with ultrasonic Extraction and Soxhlet Extraction was performed to assess the method accuracy. The effect of temperature, volume of solvent required and particle size were investigated. Method precision (RSD, n=5) between 1.98 and 3.4% was achieved for the Extraction of berberine and aristolochic acids I and II in medicinal plants and lower than 8% for lower levels of aristolochic acid II in medicinal plants.