Eugenia Gallardo - Academia.edu (original) (raw)

Papers by Eugenia Gallardo

Research paper thumbnail of Microextraction by Packed Sorbent as a Novel Strategy for Sample Clean-Up in the Determination of Methadone and EDDP in Hair

Journal of Analytical Toxicology, 2020

A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its... more A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its primary metabolite (EDDP) in hair samples was developed. The miniaturized approach coupled to gas chromatography with tandem mass spectrometry (GC–MS-MS) was successfully validated. Hair samples (50 mg) were incubated with 1 mL of 1 M sodium hydroxide for 45 min at 50°C, time after which the extract was neutralized by adding 100 μL of 20% formic acid. Subsequently, MEPS was applied using a M1 sorbent (4 mg; 80% C8 and 20% strong cation-exchange (SCX)), first conditioned with three 250-μL cycles of methanol and three 250-μL cycles of 2% formic acid. The extract load occurred with nine 150-μL cycles followed by a washing step involving three 50-μL cycles with 3.36% formic acid. For the elution of the analytes, six 100-μL cycles of 2.36% ammonium hydroxide in methanol were applied. The method was linear from 0.01 to 5 ng/mg, for both compounds, presenting determination coefficients greater...

Research paper thumbnail of Characterization of Mineral Composition and Nutritional Value of Acacia Green Pods

Plants

The Acacia genus is considered one of the most invasive taxa in some habitats, namely coastal dun... more The Acacia genus is considered one of the most invasive taxa in some habitats, namely coastal dunes, maritime calcareous soils, fresh lands in the valleys, mountainous areas, and the banks of watercourses and roadsides. In Portugal, the severity risk is very high, so this study aimed to evaluate the nutritional and mineral contents of the green pods as a potential source for livestock feeds and soil fertilizer because, as far as we know, there is no use for this species. The seven different species of Acacia (Acacia mearnsii Link, Acacia longifolia (Andrews) Willd, Acacia melanoxylon R. Br., Acacia pycnantha Bentham, Acacia dealbata Link., Acacia retinodes Schlecht, and Acacia cyclops A. Cunn. ex G. Don fil) were evaluated. The results showed that Acacia green pods have a high protein, fibre and minerals content, especially in potassium (K), calcium (Ca) and magnesium (Mg). All species present a different profile of the studied parameters, suggesting different potentials for their f...

Research paper thumbnail of Characterisation of the Phenolic Profile of Acacia retinodes and Acacia mearnsii Flowers’ Extracts

Plants

Acacia spp. is an invasive species that is widespread throughout the Portuguese territory. Thus, ... more Acacia spp. is an invasive species that is widespread throughout the Portuguese territory. Thus, it is pertinent to better understand this species in order to find different applications that will value its use. To evaluate the phenolic profile in Acacia flowers, ethanolic extracts obtained through an energized guided dispersive extraction were analysed, focusing on two species, Acacia retinodes and Acacia mearnsii, at two flowering stages. The phytochemical profile of each extract was determined by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and high-performance liquid chromatography coupled with diode array detector. The FTIR-ATR technique was used to distinguish the different samples’ compositions. The results showed the presence of high concentrations of phenolic compounds (>300 mg GAE/g extract), among which are flavonoids (>136 mg QE/g extract), for all combinations of species/flowering stages. The phytochemical p...

Research paper thumbnail of Advances on Bioanalysis: Recent Approaches in the Determination of Biomarkers, Drugs of Abuse and Medicines

Molecules

New developments in instrumental approaches, for instance, hyphenated techniques, have allowed gr... more New developments in instrumental approaches, for instance, hyphenated techniques, have allowed great advances in the bioanalytical field over the last half century, and there is no doubt that toxicology was one of the most improved areas [...]

Research paper thumbnail of New Method for the Monitoring of Antidepressants in Oral Fluid Using Dried Spot Sampling

Pharmaceuticals, 2021

The increase in the consumption of antidepressants is a public health problem worldwide, as these... more The increase in the consumption of antidepressants is a public health problem worldwide, as these are a class of compounds widely used in the treatment of several illnesses, such as depression and anxiety. This work aimed to develop and optimize a method for the quantification of a number of antidepressants and their metabolites (fluoxetine, venlafaxine, O-desmethylvenlafaxine, citalopram, sertraline, and paroxetine) in 100 µL of oral fluid using the dried saliva spots (DSS) sampling approach and gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). The method was validated, presenting linearity within the studied range, with detection and quantification limits ranging between 10 and 100 ng/mL, and coefficients of determination (R2) of at least 0.99 for all analytes. Recoveries were between approximately 13 and 46%. The analysis of precision and accuracy presented acceptable coefficients of variation and relative errors, considering the criteria usually accepted in th...

Research paper thumbnail of Determination of Selected Opiates in Hair Samples Using Microextraction by Packed Sorbent: A New Approach for Sample Clean-up

Journal of analytical toxicology, 2019

In this article the development and validation of an analytical method using microextraction by p... more In this article the development and validation of an analytical method using microextraction by packed sorbent (MEPS) to determine tramadol (TRM), codeine (COD), morphine (MOR), 6-acetylcodeine (6-AC), 6-monoacetylmorphine (6-MAM) and fentanyl (FNT) in hair samples by gas chromatography coupled to tandem mass spectrometry (GC-MS-MS) is presented. The MEPS used a mixed mode sorbent, and the steps for sample cleanup were conditioning (three cycles of 250 μL of methanol and three cycles of 250 μL formic acid 2%); sample load (15 cycles of 150 μL); wash (150 μL of 3.36% formic acid); and elution (eight cycles of 100 μL of ammonium hydroxide 2.36% (in methanol)). Linearity was obtained from the lower limit of quantitation (LLOQ) up to 5 ng/mg, with all target compounds revealing determination coefficients >0.99. The LLOQs achieved were 0.01 ng/mg for TRM, COD and 6-AC, and 0.025 ng/mg for MOR, 6-MAM and FNT. The recoveries ranged from 74 to 90% (TRM), 51 to 59% (COD), 22 to 36% (MOR),...

Research paper thumbnail of Insights into the Bioactivities and Chemical Analysis of Ailanthus altissima (Mill.) Swingle

Applied Sciences, 2021

Many species of the so-called exotic plants coexist with native species in a balanced way, but ot... more Many species of the so-called exotic plants coexist with native species in a balanced way, but others thrive very quickly and escape human control, becoming harmful—these are called invasive alien species. In addition to overcoming geographic barriers, these species can defeat biotic and abiotic barriers, maintaining stable populations. Ailanthus altissima is no exception; it is disseminated worldwide and is considered high risk due to its easy propagation and resistance to external environmental factors. Currently, it has no particular use other than ornamental, even though it is used to treat epilepsy, diarrhea, asthma, ophthalmic diseases, and seborrhoea in Chinese medicine. Considering its rich composition in alkaloids, terpenoids, sterols, and flavonoids, doubtlessly, its use in medicine or other fields can be maximised. This review will focus on the knowledge of the chemical composition and the discovery of the biological properties of A. altissima to understand this plant bet...

Research paper thumbnail of Sampling alternative specimens: hair and oral fluid

New Sampling Strategies in Toxicology and Therapeutic Drug Monitoring, 2015

Research paper thumbnail of Desenvolvimento e Validação de um Método Analítico para a Determinação de Clorpromazina en Sangue por Extracção em Fase Sólida e Cromatografia Gasosa/ Espectrometria de Massa Development and Validation of an Analytical Method to Determine Chlorpromazine in Blood using Solid-Phase Extraction and G...

Research paper thumbnail of Natural Products: Therapeutic Properties and Beyond II

Molecules

Historically, natural products have contributed to drug discovery as a source of active molecules... more Historically, natural products have contributed to drug discovery as a source of active molecules due to their great diversity and structural complexity [...]

Research paper thumbnail of Microextraction by Packed Sorbent

Microextraction Techniques in Analytical Toxicology, 2021

Research paper thumbnail of Amphetamine in biological specimens: impact and implications for public health

Handbook of Substance Misuse and Addictions, 2022

Research paper thumbnail of 491 Publications 2,088 Citations See Profile

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Research paper thumbnail of Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

Bioanalysis, 2020

One of the problems associated with the consumption of new psychoactive substances is that in mos... more One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

Research paper thumbnail of Design and Characterization of Bioactive Bilayer Films: Release Kinetics of Isopropyl Palmitate

Antibiotics, 2020

Active packaging incorporating antioxidants and antimicrobials is creating a niche in the market ... more Active packaging incorporating antioxidants and antimicrobials is creating a niche in the market and becoming increasingly important. The main goal of this work was the design of bioactive bilayer films (zein/pullulan) incorporating licorice essential oil. The bilayer films were fully characterized in terms of their chemical, physical, barrier, antioxidant, and antimicrobial properties. Furthermore, the release kinetics of isopropyl palmitate, the major compound of the licorice essential oil, was evaluated by HPLC-DAD (high-performance liquid chromatography coupled to diode-array detector). Scanning Electron Microscopy (SEM) micrographs of cross-sections of the bilayer films clearly show the two layers of the films. Besides presenting the capacity to scavenge free radicals and to inhibit the lipid peroxidation, the developed bilayer films were also able to inhibit the growth of known foodborne pathogens (Enterococcus faecalis and Listeria monocytogenes). The release kinetics profile...

Research paper thumbnail of The bitter taste receptor TAS2R14 regulates resveratrol transport across the human blood-cerebrospinal fluid barrier

Biochemical Pharmacology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Julbernardia paniculata and Pterocarpus angolensis: From Ethnobotanical Surveys to Phytochemical Characterization and Bioactivities Evaluation

Molecules, 2020

Julbernardia paniculata and Pterocarpus angolensis are two plant species with important applicati... more Julbernardia paniculata and Pterocarpus angolensis are two plant species with important application in African traditional medicine, particularly in Angola, in the treatment of several diseases. However, scientific studies concerning these species are scarce. The goal of this work was to know better which medicinal approaches are used by the Huíla population in Angola by means of ethnobotanical surveys. Furthermore, extracts of both plants were phytochemically characterized. Antioxidant, anti-inflammatory, wound-healing activities, and potential cytotoxicity were also studied. With this study it was possible to verify that 67% of the individuals that use medicinal plants are women, and their main therapeutic uses are the treatment of problems of the digestive system and skin disorders. Barks of J. paniculata and leaves of P. angolensis are the most often used plant parts. Through high-performance liquid chromatography coupled to diode-array detector (HPLC-DAD) and GC-MS it was possi...

Research paper thumbnail of Organophosphorus pesticide determination in biological specimens: bioanalytical and toxicological aspects

International Journal of Legal Medicine, 2019

Organophosphorus insecticides, such as parathion-ethyl, quinalphos, chlorpyrifos, chlorfenvinphos... more Organophosphorus insecticides, such as parathion-ethyl, quinalphos, chlorpyrifos, chlorfenvinphos or diazinon, are still widely used for pest control on crops. These compounds are extremely toxic to humans, and, even though specific legislation exists that controls the use of these substances, the frequency of toxic and/or fatal events and the existing data suggest that they are still easily accessed and the knowledge associated to the risks is not well-recognized. For these reasons, the determination of the exposure to these compounds, their detection (and of their metabolites as well) in biological samples, is of great importance in clinical and forensic toxicology, and, therefore, the development of techniques for this evaluation is an important task for laboratories. Most confirmatory analyses use blood, serum, plasma and urine as biological samples and are performed by either gas chromatographic-mass spectrometric or liquid chromatographic-mass spectrometric instrumentation, which represents the gold standard in what concerns high sensitivity. This paper will not only address the physical-chemical and toxicological aspects of this class of compounds but also perform a comprehensive and critical review on the analytical methods available for their determination in biological specimens, with special focus on the latest instrumental developments and sample preparation approaches.

Research paper thumbnail of Determination of antipsychotic drugs in hospital and wastewater treatment plant samples by gas chromatography/tandem mass spectrometry

Journal of Chromatography B, 2016

The development and performance evaluation of a method for the simultaneous determination of six ... more The development and performance evaluation of a method for the simultaneous determination of six antipsychotic drugs in hospital effluents and wastewater treatment plants (WWTP) samples are herein presented. The method involves an off-line mixed mode (reversed-phase and strong cation exchange) solid phase extraction (SPE) with gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). The present methodology was validated following internationally accepted criteria, and the studied parameters included selectivity, linearity, limits of detection (LOD) and quantitation (LLOQ), instrumental limits, precision and accuracy, stability and recovery. The procedure was linear for concentrations ranging from 0.1 to 10μg/L (0.02 to 2μg/L for haloperidol), with determination coefficients higher than 0.99 for all analytes. Intra- and inter-day precision was lower than 15% for all analytes at the studied concentrations, while accuracy remained between a ±15% interval. Recoveries ranged from 31% to 83%. Low LODs were achieved, between 2 and 10ng/L, allowing a reliable identification of all analytes at trace levels, using only 50mL as sample volume. All studied parameters complied with the defined criteria and the method was successfully applied to gather preliminary results of the determination of antipsychotics on hospital effluents and on influent and effluent of WWTPs, opening perspectives for the study of their fate in the aquatic environment.

Research paper thumbnail of Determination of antipsychotic drugs in hospital and wastewater treatment plant samples by gas chromatography/tandem mass spectrometry

Journal of Chromatography B, 2016

The development and performance evaluation of a method for the simultaneous determination of six ... more The development and performance evaluation of a method for the simultaneous determination of six antipsychotic drugs in hospital effluents and wastewater treatment plants (WWTP) samples are herein presented. The method involves an off-line mixed mode (reversed-phase and strong cation exchange) solid phase extraction (SPE) with gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). The present methodology was validated following internationally accepted criteria, and the studied parameters included selectivity, linearity, limits of detection (LOD) and quantitation (LLOQ), instrumental limits, precision and accuracy, stability and recovery. The procedure was linear for concentrations ranging from 0.1 to 10μg/L (0.02 to 2μg/L for haloperidol), with determination coefficients higher than 0.99 for all analytes. Intra- and inter-day precision was lower than 15% for all analytes at the studied concentrations, while accuracy remained between a ±15% interval. Recoveries ranged from 31% to 83%. Low LODs were achieved, between 2 and 10ng/L, allowing a reliable identification of all analytes at trace levels, using only 50mL as sample volume. All studied parameters complied with the defined criteria and the method was successfully applied to gather preliminary results of the determination of antipsychotics on hospital effluents and on influent and effluent of WWTPs, opening perspectives for the study of their fate in the aquatic environment.

Research paper thumbnail of Microextraction by Packed Sorbent as a Novel Strategy for Sample Clean-Up in the Determination of Methadone and EDDP in Hair

Journal of Analytical Toxicology, 2020

A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its... more A microextraction by packed sorbent (MEPS) procedure for rapid concentration of methadone and its primary metabolite (EDDP) in hair samples was developed. The miniaturized approach coupled to gas chromatography with tandem mass spectrometry (GC–MS-MS) was successfully validated. Hair samples (50 mg) were incubated with 1 mL of 1 M sodium hydroxide for 45 min at 50°C, time after which the extract was neutralized by adding 100 μL of 20% formic acid. Subsequently, MEPS was applied using a M1 sorbent (4 mg; 80% C8 and 20% strong cation-exchange (SCX)), first conditioned with three 250-μL cycles of methanol and three 250-μL cycles of 2% formic acid. The extract load occurred with nine 150-μL cycles followed by a washing step involving three 50-μL cycles with 3.36% formic acid. For the elution of the analytes, six 100-μL cycles of 2.36% ammonium hydroxide in methanol were applied. The method was linear from 0.01 to 5 ng/mg, for both compounds, presenting determination coefficients greater...

Research paper thumbnail of Characterization of Mineral Composition and Nutritional Value of Acacia Green Pods

Plants

The Acacia genus is considered one of the most invasive taxa in some habitats, namely coastal dun... more The Acacia genus is considered one of the most invasive taxa in some habitats, namely coastal dunes, maritime calcareous soils, fresh lands in the valleys, mountainous areas, and the banks of watercourses and roadsides. In Portugal, the severity risk is very high, so this study aimed to evaluate the nutritional and mineral contents of the green pods as a potential source for livestock feeds and soil fertilizer because, as far as we know, there is no use for this species. The seven different species of Acacia (Acacia mearnsii Link, Acacia longifolia (Andrews) Willd, Acacia melanoxylon R. Br., Acacia pycnantha Bentham, Acacia dealbata Link., Acacia retinodes Schlecht, and Acacia cyclops A. Cunn. ex G. Don fil) were evaluated. The results showed that Acacia green pods have a high protein, fibre and minerals content, especially in potassium (K), calcium (Ca) and magnesium (Mg). All species present a different profile of the studied parameters, suggesting different potentials for their f...

Research paper thumbnail of Characterisation of the Phenolic Profile of Acacia retinodes and Acacia mearnsii Flowers’ Extracts

Plants

Acacia spp. is an invasive species that is widespread throughout the Portuguese territory. Thus, ... more Acacia spp. is an invasive species that is widespread throughout the Portuguese territory. Thus, it is pertinent to better understand this species in order to find different applications that will value its use. To evaluate the phenolic profile in Acacia flowers, ethanolic extracts obtained through an energized guided dispersive extraction were analysed, focusing on two species, Acacia retinodes and Acacia mearnsii, at two flowering stages. The phytochemical profile of each extract was determined by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and high-performance liquid chromatography coupled with diode array detector. The FTIR-ATR technique was used to distinguish the different samples’ compositions. The results showed the presence of high concentrations of phenolic compounds (>300 mg GAE/g extract), among which are flavonoids (>136 mg QE/g extract), for all combinations of species/flowering stages. The phytochemical p...

Research paper thumbnail of Advances on Bioanalysis: Recent Approaches in the Determination of Biomarkers, Drugs of Abuse and Medicines

Molecules

New developments in instrumental approaches, for instance, hyphenated techniques, have allowed gr... more New developments in instrumental approaches, for instance, hyphenated techniques, have allowed great advances in the bioanalytical field over the last half century, and there is no doubt that toxicology was one of the most improved areas [...]

Research paper thumbnail of New Method for the Monitoring of Antidepressants in Oral Fluid Using Dried Spot Sampling

Pharmaceuticals, 2021

The increase in the consumption of antidepressants is a public health problem worldwide, as these... more The increase in the consumption of antidepressants is a public health problem worldwide, as these are a class of compounds widely used in the treatment of several illnesses, such as depression and anxiety. This work aimed to develop and optimize a method for the quantification of a number of antidepressants and their metabolites (fluoxetine, venlafaxine, O-desmethylvenlafaxine, citalopram, sertraline, and paroxetine) in 100 µL of oral fluid using the dried saliva spots (DSS) sampling approach and gas chromatography coupled with tandem mass spectrometry (GC–MS/MS). The method was validated, presenting linearity within the studied range, with detection and quantification limits ranging between 10 and 100 ng/mL, and coefficients of determination (R2) of at least 0.99 for all analytes. Recoveries were between approximately 13 and 46%. The analysis of precision and accuracy presented acceptable coefficients of variation and relative errors, considering the criteria usually accepted in th...

Research paper thumbnail of Determination of Selected Opiates in Hair Samples Using Microextraction by Packed Sorbent: A New Approach for Sample Clean-up

Journal of analytical toxicology, 2019

In this article the development and validation of an analytical method using microextraction by p... more In this article the development and validation of an analytical method using microextraction by packed sorbent (MEPS) to determine tramadol (TRM), codeine (COD), morphine (MOR), 6-acetylcodeine (6-AC), 6-monoacetylmorphine (6-MAM) and fentanyl (FNT) in hair samples by gas chromatography coupled to tandem mass spectrometry (GC-MS-MS) is presented. The MEPS used a mixed mode sorbent, and the steps for sample cleanup were conditioning (three cycles of 250 μL of methanol and three cycles of 250 μL formic acid 2%); sample load (15 cycles of 150 μL); wash (150 μL of 3.36% formic acid); and elution (eight cycles of 100 μL of ammonium hydroxide 2.36% (in methanol)). Linearity was obtained from the lower limit of quantitation (LLOQ) up to 5 ng/mg, with all target compounds revealing determination coefficients >0.99. The LLOQs achieved were 0.01 ng/mg for TRM, COD and 6-AC, and 0.025 ng/mg for MOR, 6-MAM and FNT. The recoveries ranged from 74 to 90% (TRM), 51 to 59% (COD), 22 to 36% (MOR),...

Research paper thumbnail of Insights into the Bioactivities and Chemical Analysis of Ailanthus altissima (Mill.) Swingle

Applied Sciences, 2021

Many species of the so-called exotic plants coexist with native species in a balanced way, but ot... more Many species of the so-called exotic plants coexist with native species in a balanced way, but others thrive very quickly and escape human control, becoming harmful—these are called invasive alien species. In addition to overcoming geographic barriers, these species can defeat biotic and abiotic barriers, maintaining stable populations. Ailanthus altissima is no exception; it is disseminated worldwide and is considered high risk due to its easy propagation and resistance to external environmental factors. Currently, it has no particular use other than ornamental, even though it is used to treat epilepsy, diarrhea, asthma, ophthalmic diseases, and seborrhoea in Chinese medicine. Considering its rich composition in alkaloids, terpenoids, sterols, and flavonoids, doubtlessly, its use in medicine or other fields can be maximised. This review will focus on the knowledge of the chemical composition and the discovery of the biological properties of A. altissima to understand this plant bet...

Research paper thumbnail of Sampling alternative specimens: hair and oral fluid

New Sampling Strategies in Toxicology and Therapeutic Drug Monitoring, 2015

Research paper thumbnail of Desenvolvimento e Validação de um Método Analítico para a Determinação de Clorpromazina en Sangue por Extracção em Fase Sólida e Cromatografia Gasosa/ Espectrometria de Massa Development and Validation of an Analytical Method to Determine Chlorpromazine in Blood using Solid-Phase Extraction and G...

Research paper thumbnail of Natural Products: Therapeutic Properties and Beyond II

Molecules

Historically, natural products have contributed to drug discovery as a source of active molecules... more Historically, natural products have contributed to drug discovery as a source of active molecules due to their great diversity and structural complexity [...]

Research paper thumbnail of Microextraction by Packed Sorbent

Microextraction Techniques in Analytical Toxicology, 2021

Research paper thumbnail of Amphetamine in biological specimens: impact and implications for public health

Handbook of Substance Misuse and Addictions, 2022

Research paper thumbnail of 491 Publications 2,088 Citations See Profile

All in-text references underlined in blue are linked to publications on ResearchGate, letting you... more All in-text references underlined in blue are linked to publications on ResearchGate, letting you access and read them immediately.

Research paper thumbnail of Recent bionalytical methods for the determination of new psychoactive substances in biological specimens

Bioanalysis, 2020

One of the problems associated with the consumption of new psychoactive substances is that in mos... more One of the problems associated with the consumption of new psychoactive substances is that in most scenarios of acute toxicity the possibility of quick clinical action may be impaired because many screening methods are not responsive to them, and laboratories are not able to keep pace with the appearance of new substances. For these reasons, developing and validating new analytical methods is mandatory in order to efficiently face those problems, allowing laboratories to be one step ahead. The goal of this work is to perform a critical review regarding bionalytical methods that can be used for the determination of new psychoactive substances (phenylethylamines, cathinones, synthetic cannabinoids, opioids, benzodiazepines, etc), particularly concerning sample preparation techniques and associated analytical methods.

Research paper thumbnail of Design and Characterization of Bioactive Bilayer Films: Release Kinetics of Isopropyl Palmitate

Antibiotics, 2020

Active packaging incorporating antioxidants and antimicrobials is creating a niche in the market ... more Active packaging incorporating antioxidants and antimicrobials is creating a niche in the market and becoming increasingly important. The main goal of this work was the design of bioactive bilayer films (zein/pullulan) incorporating licorice essential oil. The bilayer films were fully characterized in terms of their chemical, physical, barrier, antioxidant, and antimicrobial properties. Furthermore, the release kinetics of isopropyl palmitate, the major compound of the licorice essential oil, was evaluated by HPLC-DAD (high-performance liquid chromatography coupled to diode-array detector). Scanning Electron Microscopy (SEM) micrographs of cross-sections of the bilayer films clearly show the two layers of the films. Besides presenting the capacity to scavenge free radicals and to inhibit the lipid peroxidation, the developed bilayer films were also able to inhibit the growth of known foodborne pathogens (Enterococcus faecalis and Listeria monocytogenes). The release kinetics profile...

Research paper thumbnail of The bitter taste receptor TAS2R14 regulates resveratrol transport across the human blood-cerebrospinal fluid barrier

Biochemical Pharmacology, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Research paper thumbnail of Julbernardia paniculata and Pterocarpus angolensis: From Ethnobotanical Surveys to Phytochemical Characterization and Bioactivities Evaluation

Molecules, 2020

Julbernardia paniculata and Pterocarpus angolensis are two plant species with important applicati... more Julbernardia paniculata and Pterocarpus angolensis are two plant species with important application in African traditional medicine, particularly in Angola, in the treatment of several diseases. However, scientific studies concerning these species are scarce. The goal of this work was to know better which medicinal approaches are used by the Huíla population in Angola by means of ethnobotanical surveys. Furthermore, extracts of both plants were phytochemically characterized. Antioxidant, anti-inflammatory, wound-healing activities, and potential cytotoxicity were also studied. With this study it was possible to verify that 67% of the individuals that use medicinal plants are women, and their main therapeutic uses are the treatment of problems of the digestive system and skin disorders. Barks of J. paniculata and leaves of P. angolensis are the most often used plant parts. Through high-performance liquid chromatography coupled to diode-array detector (HPLC-DAD) and GC-MS it was possi...

Research paper thumbnail of Organophosphorus pesticide determination in biological specimens: bioanalytical and toxicological aspects

International Journal of Legal Medicine, 2019

Organophosphorus insecticides, such as parathion-ethyl, quinalphos, chlorpyrifos, chlorfenvinphos... more Organophosphorus insecticides, such as parathion-ethyl, quinalphos, chlorpyrifos, chlorfenvinphos or diazinon, are still widely used for pest control on crops. These compounds are extremely toxic to humans, and, even though specific legislation exists that controls the use of these substances, the frequency of toxic and/or fatal events and the existing data suggest that they are still easily accessed and the knowledge associated to the risks is not well-recognized. For these reasons, the determination of the exposure to these compounds, their detection (and of their metabolites as well) in biological samples, is of great importance in clinical and forensic toxicology, and, therefore, the development of techniques for this evaluation is an important task for laboratories. Most confirmatory analyses use blood, serum, plasma and urine as biological samples and are performed by either gas chromatographic-mass spectrometric or liquid chromatographic-mass spectrometric instrumentation, which represents the gold standard in what concerns high sensitivity. This paper will not only address the physical-chemical and toxicological aspects of this class of compounds but also perform a comprehensive and critical review on the analytical methods available for their determination in biological specimens, with special focus on the latest instrumental developments and sample preparation approaches.

Research paper thumbnail of Determination of antipsychotic drugs in hospital and wastewater treatment plant samples by gas chromatography/tandem mass spectrometry

Journal of Chromatography B, 2016

The development and performance evaluation of a method for the simultaneous determination of six ... more The development and performance evaluation of a method for the simultaneous determination of six antipsychotic drugs in hospital effluents and wastewater treatment plants (WWTP) samples are herein presented. The method involves an off-line mixed mode (reversed-phase and strong cation exchange) solid phase extraction (SPE) with gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). The present methodology was validated following internationally accepted criteria, and the studied parameters included selectivity, linearity, limits of detection (LOD) and quantitation (LLOQ), instrumental limits, precision and accuracy, stability and recovery. The procedure was linear for concentrations ranging from 0.1 to 10μg/L (0.02 to 2μg/L for haloperidol), with determination coefficients higher than 0.99 for all analytes. Intra- and inter-day precision was lower than 15% for all analytes at the studied concentrations, while accuracy remained between a ±15% interval. Recoveries ranged from 31% to 83%. Low LODs were achieved, between 2 and 10ng/L, allowing a reliable identification of all analytes at trace levels, using only 50mL as sample volume. All studied parameters complied with the defined criteria and the method was successfully applied to gather preliminary results of the determination of antipsychotics on hospital effluents and on influent and effluent of WWTPs, opening perspectives for the study of their fate in the aquatic environment.

Research paper thumbnail of Determination of antipsychotic drugs in hospital and wastewater treatment plant samples by gas chromatography/tandem mass spectrometry

Journal of Chromatography B, 2016

The development and performance evaluation of a method for the simultaneous determination of six ... more The development and performance evaluation of a method for the simultaneous determination of six antipsychotic drugs in hospital effluents and wastewater treatment plants (WWTP) samples are herein presented. The method involves an off-line mixed mode (reversed-phase and strong cation exchange) solid phase extraction (SPE) with gas chromatography (GC) coupled to tandem mass spectrometry (MS/MS). The present methodology was validated following internationally accepted criteria, and the studied parameters included selectivity, linearity, limits of detection (LOD) and quantitation (LLOQ), instrumental limits, precision and accuracy, stability and recovery. The procedure was linear for concentrations ranging from 0.1 to 10μg/L (0.02 to 2μg/L for haloperidol), with determination coefficients higher than 0.99 for all analytes. Intra- and inter-day precision was lower than 15% for all analytes at the studied concentrations, while accuracy remained between a ±15% interval. Recoveries ranged from 31% to 83%. Low LODs were achieved, between 2 and 10ng/L, allowing a reliable identification of all analytes at trace levels, using only 50mL as sample volume. All studied parameters complied with the defined criteria and the method was successfully applied to gather preliminary results of the determination of antipsychotics on hospital effluents and on influent and effluent of WWTPs, opening perspectives for the study of their fate in the aquatic environment.