Renato Zanella | UFSM - Universidade Federal de Santa Maria (original) (raw)

Papers by Renato Zanella

Science of The Total Environment, 2015

Selective herbicides in paddy rice fields, do not affect water quality.

Journal of the Brazilian Chemical Society

A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in... more A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in tomatoes and cucumbers grown in experimental greenhouses was developed and validated. The vegetables were submitted to a single spraying with chlorothalonil at half, equal to and double of the recommended dose. Chlorothalonil residues were extracted in Ultra-Turrax system using ethyl acetate in the presence of anhydrous sodium sulphate and determined by gas chromatography with electron capture detection. The analytical curves were linear from 0.005 to 5.0 mg L-1, with coefficient of determination higher then 0.995. The assays provide acceptable results with RSD values below 10.5% and recoveries were between 92.2 and 114.5% for tomatoes, and between 86.2 and 103.3% for cucumbers, both obtained from spiked samples at 0.028, 0.28, 2.8 and 5.0 mg kg-1 levels. Statistical interpretation of residue levels fitted to a first-order model for the dissipation behavior of chlorothalonil. The mean h...

Journal of the Brazilian Chemical Society, 2015

Science of The Total Environment, 2015

Selective herbicides in paddy rice fields, do not affect water quality.

Analytical and Bioanalytical Chemistry, 2013

Pollution of drinking water supplies from industrial waste is a result of several industrial proc... more Pollution of drinking water supplies from industrial waste is a result of several industrial processes and disposal practices, and the establishment of analytical methods for monitoring organic compounds related to environmental and health problems is very important. In this work, a method using solid-phase extraction (SPE) and gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS) was developed and validated for the simultaneous determination of pesticide residues and related compounds in drinking and surface water as well as in industrial effluent. Optimization of the method was achieved by using a central composite design approach on parameters such as the sample pH and SPE eluent composition. A single SPE consisting of the loading on a polymeric sorbent of 100 mL of sample adjusted to pH 3 and elution with methanol/methylene chloride (10:90, v/v) permitted the obtaining of acceptable recoveries in most cases. The concentration factor associated with sensitivity of the chromatographic analysis permitted the achievement of the method limit of detection values between 0.01 and 0.25 μg L(-1). Recovery assays presented mean recoveries between 70 and 120% for most of the compounds with very good precision, despite the different chemical nature of the compounds analyzed. The selectivity of the method, evaluated through the relative intensity of quantification and qualification ions obtained by GC-QqQ-MS/MS, was considered adequate. The developed method was finally applied to the determination of target analytes in real samples. River water and treated industrial effluent samples presented residues of some compounds, but no detectable residues were found in the drinking water samples evaluated.

Journal of the Brazilian Chemical Society, 2014

O mel pode apresentar resíduos de pesticidas devido à contaminação das abelhas durante a coleta d... more O mel pode apresentar resíduos de pesticidas devido à contaminação das abelhas durante a coleta de pólen e néctar ou por tratamento das colmeias. Assim, a determinação de resíduos de pesticidas em mel é de grande importância, apesar da dificuldade devido à complexidade da matriz. Neste estudo, um novo método para a determinação de pesticidas de diferentes grupos químicos em mel foi desenvolvido e validado. Amostras de mel foram extraídas pelo método QuEChERS modificado e analisados por cromatografia gasosa com detecção por captura de elétrons (GC-ECD). Os resultados de recuperação, avaliados em três níveis de fortificação, foram entre 71 e 119% para a maioria dos compostos, com valores de desvio padrão relativo (RSD) < 20%. O método proposto permite a determinação com limites de detecção entre 3 e 6 µg kg -1 , combinando a extração e limpeza do extrato de forma efetiva, com boa sensibilidade e seletividade, e foi aplicado com sucesso na análise de amostras comerciais de mel.

South African Journal of Chemistry, 2015

Food Chemistry, 2016

In this study, different extraction procedures based on the QuEChERS method were compared for the... more In this study, different extraction procedures based on the QuEChERS method were compared for the multiresidue determination of pesticides in orange juice by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). After choosing preliminary conditions, an experimental design was carried out with the variables C18, PSA, NaOH and CH3COONa to optimize the sample preparation step. The validation results of the validation were satisfactory, since the method presented recoveries between 70% and 118%, with RSD lower than 19% for spike levels between 10 and 100μgL(-1). The method limit of detection (LOD) and limit of quantification (LOQ) ranged from 3.0 to 7.6μgL(-1) and from 4.9 to 26μgL(-1), respectively. The method developed was adequate for the determination of 74 pesticide residues in orange juice.

Journal of Chromatography A, 2015

The use of pesticides in agriculture has generated numerous consequences to the environment, requ... more The use of pesticides in agriculture has generated numerous consequences to the environment, requiring analysis of the persistent residues in soil, water and air. The variability of soil properties interferes in the extraction of pesticide residues with robustness and accuracy. The group of imidazolinones herbicides, widely used for weed control, becomes an additional task in multiresidue extraction procedures because of their low pKa values. In order to determine these compounds in soil samples, different methods have been proposed, however they can be very laborious and require more time and well trained analysts. Thus, this study aimed to develop a simple and efficient method for determination of imidazolinones (imazamox, imazapic, imazapyr, imazaquin and imazethapyr) residues in soil, using an extraction with aqueous ammonium acetate solution (0.5 M) and clean-up with dispersive solid phase extraction employing PSA, followed by UHPLC-MS/MS analysis. Satisfactory values of accuracy (70-93%) and RSD (≤17%) were achieved, as well as lower limit of quantification (5.0 μg kg(-1)). Considering the matrix and compounds complexity, the developed and validated method proved to be an excellent tool for rapid analysis (20 min), with reliability for application in real samples with wide pH range. In the analysis of 22 real samples, the method allowed the quantification of imazapic (5.84 and 12.1 μg kg(-1)), imazapyr (5.3 μg kg(-1)) and imazethapyr (24.0 and 37.7 μg kg(-1)) in three samples.

Scientia Agricola, 2008

Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at enviro... more Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at environmentally relevant concentrations. Fingerlings of the common carp (Cyprinus carpio, Linnaeus, 1758), grass carp (Ctenopharyngodon idella, Valenciennes, 1844), and bighead carp (Aristichthys nobilis, Richardson, 1845) were exposed to diafuran, an insecticide widely used during rice cultivation in Southern Brazil. The aim of this study was to verify the relationship between the lethal concentration (LC 50 ) of diafuran and the acetylcholinesterase (AChE) activity in brain and muscle tissues of these species as a possible early biomarker of exposure to this insecticide. LC 50 was determined for fish exposed to diafuran concentrations during 96 h (short term): common carp: control, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mg L -1 ; grass carp: control, 1.0, 2.0, 3.0 and 3.5 mg L -1 and, bighead carp: control, 0.5, 1.0, 1.5, 2.0, 3.0 and 4.0 mg L -1 , as well as the determination of AChE at concentrations near LC 50 for these species. LC 50 values (nominal concentrations) were 1.81 mg L -1 for the common carp, 2.71 mg L -1 for the grass carp and, 2.37 mg L -1 for the bighead carp. All carps exposed to diafuran were lethargic (lower concentrations) or immobile. Diafuran inhibited the acetylcholinesterase activity in brain (~38%) and muscle (~50%) of all species. Muscle of bighead carp under control treatment showed higher specific AChE activity than brain (14.44 against 5.94 mmol min -1 g protein -1 , respectively). Concentrations of diafuran used for rice cropping may affect Cyprinus carpio, Ctenopharyngodon idella and Aristichthys nobilis behaviors and the AChE activities in brain and muscle of these species may be an early biomarker of toxicity of this insecticide.

Planta Daninha

Herbicides can persist in soil and be transported from the application site to the environment. A... more Herbicides can persist in soil and be transported from the application site to the environment. An experiment was conducted to estimate imazethapyr and clomazone persistence in rice paddy water. The treatments included application of the formulated herbicide mixture (imazethapyr 75ga.i.L-1 + imazapic 25ga.i.L-1) and clomazone (500ga.i.L-1). Imazethapyr and clomazone concentrations in water were evaluated from the 1st to the 62nd day after flooding. The period of herbicide detection in water was longer for imazethapyr. Imazethapyr half-life in paddy water varied between 1.6 and 6.2 days and clomazone half-life was 5days.

Chemosphere, 2014

A modified version of the QuEChERS method has been evaluated for the determination of 21 pharmace... more A modified version of the QuEChERS method has been evaluated for the determination of 21 pharmaceuticals and 6 personal care products (PPCPs) in drinking-water sludge samples by employing ultra high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The performance of the method was evaluated through linearity, recovery, precision (intra-day), method detection and quantification limits (MDL and MQL) and matrix effect. The calibration curves prepared in acetonitrile and in the matrix extract showed a correlation coefficient ranging from 0.98 to 0.99. MQLs values were on the ng g(-1) order of magnitude for most compounds. Recoveries between 50% and 93% were reached with RSDs lower than 10% for most compounds. Matrix effect was almost absent with values lower than 16% for 93% of the compounds. By coupling a quick and simple extraction called QuEChERS with the UPLC-MS/MS analysis, a method that is both selective and sensitive was obtained. This methodology was successfully applied to real samples and caffeine and benzophenone-3 were detected in ng g(-1) levels.

Ecotoxicology and Environmental Safety, 2012

The occurrence of pollutants in the aquatic environment can produce severe toxic effects on non-t... more The occurrence of pollutants in the aquatic environment can produce severe toxic effects on non-target organisms, including fish. These sources of contamination are numerous and include herbicides, which represent a large group of toxic chemicals. Quinclorac, an herbicide widely applied in agriculture, induces oxidative stress due to free radical generation and changes in the antioxidant defense system. The aim of this study was to assess if dietary diphenyl diselenide (PhSe) 2 has a protective effect in tissues of fish species Cyprinus carpio exposed to the quinclorac herbicide. The fish were fed with either a standard or a diet containing 3.0 mg/Kg of diphenyl diselenide for 60 d. After were exposed to 1 mg/L of Facet s (quinclorac commercial formulation) for 192 h. At the end of the experimental period, parameters as thiobarbituric acid-reactive substance levels (TBARS), protein carbonyl, catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), nonprotein thiols (NPSH) and ascorbic acid in the liver, gills, brain and muscle were evaluated in Cyprinus carpio. In fish exposed to quinclorac and feeding with standard diet TBARS levels increased in liver and gills. However, SOD activity decreases in liver whereas no alterations were observed in catalase activity in this tissue. Quinclorac also decrease GST activity in liver and brain, NPSH in brain and muscle and ascorbic acid in muscle. Concerning protein carbonyl exposed to herbicide the fish did not show any alterations. The diphenyl diselenide supplemented diet reversed these effects, preventing increases in TBARS levels in liver and gills. GST activity was recovered to control values in liver. NPSH levels in brain and muscle increased remain near to control values. These results indicated that dietary diphenyl diselenide protects tissues against quinclorac induced oxidative stress ameliorating the antioxidant properties.

Journal of the Brazilian Chemical Society, 2013

Journal of chromatography. A, Jan 10, 2009

In this study, a new modulator that is simple, robust and presents low operation costs, was devel... more In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GCxGC) system. The results show a variation in the peak area less than 3 and 5% to alkanes and pesticides, respectively. The standard deviations for the retention times in the first and second dimension are around 0.05 min and 0.05s for all the compounds. The system was optimized with n-alkanes. The GCxGC system proposed was applied in the determination of pyrethroid pesticides (bifenthrin, cypermethrin, deltamethrin, fenvalerate, esfenvalerate, cis- and trans-permethrin) in grape samples. Samples were extracted by the mini-Luke modified method and pesticides were quantified by comprehensive multidimensional gas chromatography with micro electron-capture detection (microECD). The values of method limit of...

Chromatographic Science Series, 2015

Scientia Chromatographica, 2011

Journal of the Brazilian Chemical Society, 2010

Science of The Total Environment, 2015

Selective herbicides in paddy rice fields, do not affect water quality.

Journal of the Brazilian Chemical Society

A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in... more A new method to evaluate the levels of residue and the dissipation of chlorothalonil fungicide in tomatoes and cucumbers grown in experimental greenhouses was developed and validated. The vegetables were submitted to a single spraying with chlorothalonil at half, equal to and double of the recommended dose. Chlorothalonil residues were extracted in Ultra-Turrax system using ethyl acetate in the presence of anhydrous sodium sulphate and determined by gas chromatography with electron capture detection. The analytical curves were linear from 0.005 to 5.0 mg L-1, with coefficient of determination higher then 0.995. The assays provide acceptable results with RSD values below 10.5% and recoveries were between 92.2 and 114.5% for tomatoes, and between 86.2 and 103.3% for cucumbers, both obtained from spiked samples at 0.028, 0.28, 2.8 and 5.0 mg kg-1 levels. Statistical interpretation of residue levels fitted to a first-order model for the dissipation behavior of chlorothalonil. The mean h...

Journal of the Brazilian Chemical Society, 2015

Science of The Total Environment, 2015

Selective herbicides in paddy rice fields, do not affect water quality.

Analytical and Bioanalytical Chemistry, 2013

Pollution of drinking water supplies from industrial waste is a result of several industrial proc... more Pollution of drinking water supplies from industrial waste is a result of several industrial processes and disposal practices, and the establishment of analytical methods for monitoring organic compounds related to environmental and health problems is very important. In this work, a method using solid-phase extraction (SPE) and gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS) was developed and validated for the simultaneous determination of pesticide residues and related compounds in drinking and surface water as well as in industrial effluent. Optimization of the method was achieved by using a central composite design approach on parameters such as the sample pH and SPE eluent composition. A single SPE consisting of the loading on a polymeric sorbent of 100 mL of sample adjusted to pH 3 and elution with methanol/methylene chloride (10:90, v/v) permitted the obtaining of acceptable recoveries in most cases. The concentration factor associated with sensitivity of the chromatographic analysis permitted the achievement of the method limit of detection values between 0.01 and 0.25 μg L(-1). Recovery assays presented mean recoveries between 70 and 120% for most of the compounds with very good precision, despite the different chemical nature of the compounds analyzed. The selectivity of the method, evaluated through the relative intensity of quantification and qualification ions obtained by GC-QqQ-MS/MS, was considered adequate. The developed method was finally applied to the determination of target analytes in real samples. River water and treated industrial effluent samples presented residues of some compounds, but no detectable residues were found in the drinking water samples evaluated.

Journal of the Brazilian Chemical Society, 2014

O mel pode apresentar resíduos de pesticidas devido à contaminação das abelhas durante a coleta d... more O mel pode apresentar resíduos de pesticidas devido à contaminação das abelhas durante a coleta de pólen e néctar ou por tratamento das colmeias. Assim, a determinação de resíduos de pesticidas em mel é de grande importância, apesar da dificuldade devido à complexidade da matriz. Neste estudo, um novo método para a determinação de pesticidas de diferentes grupos químicos em mel foi desenvolvido e validado. Amostras de mel foram extraídas pelo método QuEChERS modificado e analisados por cromatografia gasosa com detecção por captura de elétrons (GC-ECD). Os resultados de recuperação, avaliados em três níveis de fortificação, foram entre 71 e 119% para a maioria dos compostos, com valores de desvio padrão relativo (RSD) < 20%. O método proposto permite a determinação com limites de detecção entre 3 e 6 µg kg -1 , combinando a extração e limpeza do extrato de forma efetiva, com boa sensibilidade e seletividade, e foi aplicado com sucesso na análise de amostras comerciais de mel.

South African Journal of Chemistry, 2015

Food Chemistry, 2016

In this study, different extraction procedures based on the QuEChERS method were compared for the... more In this study, different extraction procedures based on the QuEChERS method were compared for the multiresidue determination of pesticides in orange juice by ultra high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). After choosing preliminary conditions, an experimental design was carried out with the variables C18, PSA, NaOH and CH3COONa to optimize the sample preparation step. The validation results of the validation were satisfactory, since the method presented recoveries between 70% and 118%, with RSD lower than 19% for spike levels between 10 and 100μgL(-1). The method limit of detection (LOD) and limit of quantification (LOQ) ranged from 3.0 to 7.6μgL(-1) and from 4.9 to 26μgL(-1), respectively. The method developed was adequate for the determination of 74 pesticide residues in orange juice.

Journal of Chromatography A, 2015

The use of pesticides in agriculture has generated numerous consequences to the environment, requ... more The use of pesticides in agriculture has generated numerous consequences to the environment, requiring analysis of the persistent residues in soil, water and air. The variability of soil properties interferes in the extraction of pesticide residues with robustness and accuracy. The group of imidazolinones herbicides, widely used for weed control, becomes an additional task in multiresidue extraction procedures because of their low pKa values. In order to determine these compounds in soil samples, different methods have been proposed, however they can be very laborious and require more time and well trained analysts. Thus, this study aimed to develop a simple and efficient method for determination of imidazolinones (imazamox, imazapic, imazapyr, imazaquin and imazethapyr) residues in soil, using an extraction with aqueous ammonium acetate solution (0.5 M) and clean-up with dispersive solid phase extraction employing PSA, followed by UHPLC-MS/MS analysis. Satisfactory values of accuracy (70-93%) and RSD (≤17%) were achieved, as well as lower limit of quantification (5.0 μg kg(-1)). Considering the matrix and compounds complexity, the developed and validated method proved to be an excellent tool for rapid analysis (20 min), with reliability for application in real samples with wide pH range. In the analysis of 22 real samples, the method allowed the quantification of imazapic (5.84 and 12.1 μg kg(-1)), imazapyr (5.3 μg kg(-1)) and imazethapyr (24.0 and 37.7 μg kg(-1)) in three samples.

Scientia Agricola, 2008

Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at enviro... more Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at environmentally relevant concentrations. Fingerlings of the common carp (Cyprinus carpio, Linnaeus, 1758), grass carp (Ctenopharyngodon idella, Valenciennes, 1844), and bighead carp (Aristichthys nobilis, Richardson, 1845) were exposed to diafuran, an insecticide widely used during rice cultivation in Southern Brazil. The aim of this study was to verify the relationship between the lethal concentration (LC 50 ) of diafuran and the acetylcholinesterase (AChE) activity in brain and muscle tissues of these species as a possible early biomarker of exposure to this insecticide. LC 50 was determined for fish exposed to diafuran concentrations during 96 h (short term): common carp: control, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mg L -1 ; grass carp: control, 1.0, 2.0, 3.0 and 3.5 mg L -1 and, bighead carp: control, 0.5, 1.0, 1.5, 2.0, 3.0 and 4.0 mg L -1 , as well as the determination of AChE at concentrations near LC 50 for these species. LC 50 values (nominal concentrations) were 1.81 mg L -1 for the common carp, 2.71 mg L -1 for the grass carp and, 2.37 mg L -1 for the bighead carp. All carps exposed to diafuran were lethargic (lower concentrations) or immobile. Diafuran inhibited the acetylcholinesterase activity in brain (~38%) and muscle (~50%) of all species. Muscle of bighead carp under control treatment showed higher specific AChE activity than brain (14.44 against 5.94 mmol min -1 g protein -1 , respectively). Concentrations of diafuran used for rice cropping may affect Cyprinus carpio, Ctenopharyngodon idella and Aristichthys nobilis behaviors and the AChE activities in brain and muscle of these species may be an early biomarker of toxicity of this insecticide.

Planta Daninha

Herbicides can persist in soil and be transported from the application site to the environment. A... more Herbicides can persist in soil and be transported from the application site to the environment. An experiment was conducted to estimate imazethapyr and clomazone persistence in rice paddy water. The treatments included application of the formulated herbicide mixture (imazethapyr 75ga.i.L-1 + imazapic 25ga.i.L-1) and clomazone (500ga.i.L-1). Imazethapyr and clomazone concentrations in water were evaluated from the 1st to the 62nd day after flooding. The period of herbicide detection in water was longer for imazethapyr. Imazethapyr half-life in paddy water varied between 1.6 and 6.2 days and clomazone half-life was 5days.

Chemosphere, 2014

A modified version of the QuEChERS method has been evaluated for the determination of 21 pharmace... more A modified version of the QuEChERS method has been evaluated for the determination of 21 pharmaceuticals and 6 personal care products (PPCPs) in drinking-water sludge samples by employing ultra high liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The performance of the method was evaluated through linearity, recovery, precision (intra-day), method detection and quantification limits (MDL and MQL) and matrix effect. The calibration curves prepared in acetonitrile and in the matrix extract showed a correlation coefficient ranging from 0.98 to 0.99. MQLs values were on the ng g(-1) order of magnitude for most compounds. Recoveries between 50% and 93% were reached with RSDs lower than 10% for most compounds. Matrix effect was almost absent with values lower than 16% for 93% of the compounds. By coupling a quick and simple extraction called QuEChERS with the UPLC-MS/MS analysis, a method that is both selective and sensitive was obtained. This methodology was successfully applied to real samples and caffeine and benzophenone-3 were detected in ng g(-1) levels.

Ecotoxicology and Environmental Safety, 2012

The occurrence of pollutants in the aquatic environment can produce severe toxic effects on non-t... more The occurrence of pollutants in the aquatic environment can produce severe toxic effects on non-target organisms, including fish. These sources of contamination are numerous and include herbicides, which represent a large group of toxic chemicals. Quinclorac, an herbicide widely applied in agriculture, induces oxidative stress due to free radical generation and changes in the antioxidant defense system. The aim of this study was to assess if dietary diphenyl diselenide (PhSe) 2 has a protective effect in tissues of fish species Cyprinus carpio exposed to the quinclorac herbicide. The fish were fed with either a standard or a diet containing 3.0 mg/Kg of diphenyl diselenide for 60 d. After were exposed to 1 mg/L of Facet s (quinclorac commercial formulation) for 192 h. At the end of the experimental period, parameters as thiobarbituric acid-reactive substance levels (TBARS), protein carbonyl, catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), nonprotein thiols (NPSH) and ascorbic acid in the liver, gills, brain and muscle were evaluated in Cyprinus carpio. In fish exposed to quinclorac and feeding with standard diet TBARS levels increased in liver and gills. However, SOD activity decreases in liver whereas no alterations were observed in catalase activity in this tissue. Quinclorac also decrease GST activity in liver and brain, NPSH in brain and muscle and ascorbic acid in muscle. Concerning protein carbonyl exposed to herbicide the fish did not show any alterations. The diphenyl diselenide supplemented diet reversed these effects, preventing increases in TBARS levels in liver and gills. GST activity was recovered to control values in liver. NPSH levels in brain and muscle increased remain near to control values. These results indicated that dietary diphenyl diselenide protects tissues against quinclorac induced oxidative stress ameliorating the antioxidant properties.

Journal of the Brazilian Chemical Society, 2013

Journal of chromatography. A, Jan 10, 2009

In this study, a new modulator that is simple, robust and presents low operation costs, was devel... more In this study, a new modulator that is simple, robust and presents low operation costs, was developed. This modulator uses compressed air to cool two small portions in the first centimeters of the second chromatographic column of a comprehensive multidimensional gas chromatography (GCxGC) system. The results show a variation in the peak area less than 3 and 5% to alkanes and pesticides, respectively. The standard deviations for the retention times in the first and second dimension are around 0.05 min and 0.05s for all the compounds. The system was optimized with n-alkanes. The GCxGC system proposed was applied in the determination of pyrethroid pesticides (bifenthrin, cypermethrin, deltamethrin, fenvalerate, esfenvalerate, cis- and trans-permethrin) in grape samples. Samples were extracted by the mini-Luke modified method and pesticides were quantified by comprehensive multidimensional gas chromatography with micro electron-capture detection (microECD). The values of method limit of...

Chromatographic Science Series, 2015

Scientia Chromatographica, 2011

Journal of the Brazilian Chemical Society, 2010