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Papers by CARLOS DANIEL RAMOS CONTRERAS
2019 Congreso Colombiano y Conferencia Internacional de Calidad de Aire y Salud Pública (CASP)
The optimization of an analytical methodology for the determination of the 16-priority polycyclic... more The optimization of an analytical methodology for the determination of the 16-priority polycyclic aromatic hydrocarbons (PAHs) established by the American Environmental Protection Agency-EPA, in atmospheric particulate material was developed. The methodology consists of the combination of two analysis techniques: Vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) and extraction with pressurized hot water (PHWE) and subsequent quantification by gas chromatography coupled to mass spectrometry (CG / MS). Box-Behnken surface designs were applied which allowed to determine the best experimental conditions to maximize the response, defined as the area signal of the 16 PAHs under study. The optimal conditions established were; vortex time: 10s, centrifugation time: 10 min, centrifugation speed: 3000 rpm for the VA-DLLME technique and quantity of organic modifier 10%, extraction time: 10 min and extraction temperature: 150 ºC for the PHWE technique. The developed method showed adequate linearity (r2> 0.99) and the analysis of the SRM 1649b reference material showed the accuracy of the method, obtaining recovery percentages in the range of 81.45 to 99.8%.
Los Hidrocarburos Aromaticos Policiclicos (HAPs) son compuestos quimicos que se encuentran en el ... more Los Hidrocarburos Aromaticos Policiclicos (HAPs) son compuestos quimicos que se encuentran en el ambiente en fase gaseosa y particulada, y presentan caracteristicas quimicas y biologicas asociadas con efectos negativos para la salud. 16 HAPs han sido clasificados como contaminantes prioritarios por la Agencia de Proteccion Ambiental de los Estados Unidos y mediante la Resolucion 2254 de 2017, el Ministerio de Ambiente y Desarrollo Sostenible colombiano establecio el nivel maximo permisible de estos contaminantes en el aire , evidenciando la necesidad cientifica y tecnologica de metodologias confiables para su determinacion en esa matriz. El presente trabajo presenta una novedosa metodologia para la extraccion de HAPs en material particulado PM10 enmarcada en los principios de la quimica verde como una alternativa a los metodos tradicionales que consumen gran cantidad de solventes peligrosos para las personas y el medio ambiente. EL metodo propuesto consta de dos tecnicas analiticas:...
Total organic carbon (TOC) quantification in sediments and soils samples is a tool to evaluate th... more Total organic carbon (TOC) quantification in sediments and soils samples is a tool to evaluate the organic matter content in these matrixes. This study aims to verify the fitness for use of the methodology for spectrophotometric analysis by sulphochromic oxidation described in ISO 14235: 1998 with adjustments related to digestion conditions, and its applicability to the analysis of samples of such matrices in the GAIA Research Group Laboratory of University of Antioquia. The validation was performed by determining the following parameters: linearity, working range, detection and quantification limits, accuracy and precision (repeatability and intermediate precision). Results show a significant matrix effect (α= 0.05) for soil samples analysis, the measurement range was established between 2.0 – 10 mg C, with a detection limit of 0.4 mg C and good linear fitness ((r2 > 0.995). Coefficients of variation ranged between the expected values for the concentration levels tested (<5%)...
Revista EIA, 2018
Las prácticas agropecuarias alrededor de los cuerpos de agua representan un riesgo de contaminaci... more Las prácticas agropecuarias alrededor de los cuerpos de agua representan un riesgo de contaminación por el ingreso de productos agrícolas como los plaguicidas. Esto no solo es un problema por el impacto que tienen estos compuestos sobre el ecosistema y la salud pública sino por los productos generados de su transformación en el ambiente, que en muchos casos pueden ser más tóxicos que el mismo compuesto parental. Uno de los plaguicidas más usado en Colombia es el Clorpirifos y ha sido asociado con la contaminación de fuentes hídricas. Este estudio evalúa el potencial de lixiviación del Clorpirifos desde la superficie del suelo a lo largo de un perfil de un Entisol en zona de influencia del embalse Riogrande II. La lixiviación del Clorpirifos se estudió durante 84 días después de aplicar 4,8 kg/ha del ingrediente activo a través de un lisímetro con un área de 1m2. El compuesto se detectó en las muestras de suelo en un rango de 10,0 a 9678,8 ug/kg alcanzando profundidades de 56 cm. L...
Environmental Research, Engineering and Management, 2015
Daphnia pulex assays (48 hours) were performed to determine acute toxicity of water samples from ... more Daphnia pulex assays (48 hours) were performed to determine acute toxicity of water samples from La Fe reservoir, Antioquia, Colombia. Eight sampling campaigns were done between March 2010 and June 2012, a period that included rainfall episodes. Samples were taken from the water column at three depths and from lotic areas. Physicochemical properties such as pH, electrical conductivity, temperature and dissolved oxygen were measured both in field and laboratory, and concentrations of dissolved iron (Fe), manganese (Mn), aluminium (Al), lead (Pb), cadmium (Cd) and chromium (Cr) were assessed. The overall results for the physicochemical properties remained at expected levels for natural waters with slightly higher conductivities in samples collected from bottom and some tributaries. The results of the toxicity tests showed significant mortalities in only 28% of assays. A higher mortality of Daphnia pulex was detected for tests performed during periods of higher precipitation (August 2010, February and July 2011) mainly for samples taken near the confluence of natural tributaries. No significant relationships between physicochemical variables and mortality of Daphnia pulex were found.
2019 Congreso Colombiano y Conferencia Internacional de Calidad de Aire y Salud Pública (CASP)
The optimization of an analytical methodology for the determination of the 16-priority polycyclic... more The optimization of an analytical methodology for the determination of the 16-priority polycyclic aromatic hydrocarbons (PAHs) established by the American Environmental Protection Agency-EPA, in atmospheric particulate material was developed. The methodology consists of the combination of two analysis techniques: Vortex-assisted dispersive liquid-liquid microextraction (VA-DLLME) and extraction with pressurized hot water (PHWE) and subsequent quantification by gas chromatography coupled to mass spectrometry (CG / MS). Box-Behnken surface designs were applied which allowed to determine the best experimental conditions to maximize the response, defined as the area signal of the 16 PAHs under study. The optimal conditions established were; vortex time: 10s, centrifugation time: 10 min, centrifugation speed: 3000 rpm for the VA-DLLME technique and quantity of organic modifier 10%, extraction time: 10 min and extraction temperature: 150 ºC for the PHWE technique. The developed method showed adequate linearity (r2> 0.99) and the analysis of the SRM 1649b reference material showed the accuracy of the method, obtaining recovery percentages in the range of 81.45 to 99.8%.
Los Hidrocarburos Aromaticos Policiclicos (HAPs) son compuestos quimicos que se encuentran en el ... more Los Hidrocarburos Aromaticos Policiclicos (HAPs) son compuestos quimicos que se encuentran en el ambiente en fase gaseosa y particulada, y presentan caracteristicas quimicas y biologicas asociadas con efectos negativos para la salud. 16 HAPs han sido clasificados como contaminantes prioritarios por la Agencia de Proteccion Ambiental de los Estados Unidos y mediante la Resolucion 2254 de 2017, el Ministerio de Ambiente y Desarrollo Sostenible colombiano establecio el nivel maximo permisible de estos contaminantes en el aire , evidenciando la necesidad cientifica y tecnologica de metodologias confiables para su determinacion en esa matriz. El presente trabajo presenta una novedosa metodologia para la extraccion de HAPs en material particulado PM10 enmarcada en los principios de la quimica verde como una alternativa a los metodos tradicionales que consumen gran cantidad de solventes peligrosos para las personas y el medio ambiente. EL metodo propuesto consta de dos tecnicas analiticas:...
Total organic carbon (TOC) quantification in sediments and soils samples is a tool to evaluate th... more Total organic carbon (TOC) quantification in sediments and soils samples is a tool to evaluate the organic matter content in these matrixes. This study aims to verify the fitness for use of the methodology for spectrophotometric analysis by sulphochromic oxidation described in ISO 14235: 1998 with adjustments related to digestion conditions, and its applicability to the analysis of samples of such matrices in the GAIA Research Group Laboratory of University of Antioquia. The validation was performed by determining the following parameters: linearity, working range, detection and quantification limits, accuracy and precision (repeatability and intermediate precision). Results show a significant matrix effect (α= 0.05) for soil samples analysis, the measurement range was established between 2.0 – 10 mg C, with a detection limit of 0.4 mg C and good linear fitness ((r2 > 0.995). Coefficients of variation ranged between the expected values for the concentration levels tested (<5%)...
Revista EIA, 2018
Las prácticas agropecuarias alrededor de los cuerpos de agua representan un riesgo de contaminaci... more Las prácticas agropecuarias alrededor de los cuerpos de agua representan un riesgo de contaminación por el ingreso de productos agrícolas como los plaguicidas. Esto no solo es un problema por el impacto que tienen estos compuestos sobre el ecosistema y la salud pública sino por los productos generados de su transformación en el ambiente, que en muchos casos pueden ser más tóxicos que el mismo compuesto parental. Uno de los plaguicidas más usado en Colombia es el Clorpirifos y ha sido asociado con la contaminación de fuentes hídricas. Este estudio evalúa el potencial de lixiviación del Clorpirifos desde la superficie del suelo a lo largo de un perfil de un Entisol en zona de influencia del embalse Riogrande II. La lixiviación del Clorpirifos se estudió durante 84 días después de aplicar 4,8 kg/ha del ingrediente activo a través de un lisímetro con un área de 1m2. El compuesto se detectó en las muestras de suelo en un rango de 10,0 a 9678,8 ug/kg alcanzando profundidades de 56 cm. L...
Environmental Research, Engineering and Management, 2015
Daphnia pulex assays (48 hours) were performed to determine acute toxicity of water samples from ... more Daphnia pulex assays (48 hours) were performed to determine acute toxicity of water samples from La Fe reservoir, Antioquia, Colombia. Eight sampling campaigns were done between March 2010 and June 2012, a period that included rainfall episodes. Samples were taken from the water column at three depths and from lotic areas. Physicochemical properties such as pH, electrical conductivity, temperature and dissolved oxygen were measured both in field and laboratory, and concentrations of dissolved iron (Fe), manganese (Mn), aluminium (Al), lead (Pb), cadmium (Cd) and chromium (Cr) were assessed. The overall results for the physicochemical properties remained at expected levels for natural waters with slightly higher conductivities in samples collected from bottom and some tributaries. The results of the toxicity tests showed significant mortalities in only 28% of assays. A higher mortality of Daphnia pulex was detected for tests performed during periods of higher precipitation (August 2010, February and July 2011) mainly for samples taken near the confluence of natural tributaries. No significant relationships between physicochemical variables and mortality of Daphnia pulex were found.