Pub Date : 2021-03-25DOI: 10.15446/REV.COLOMB.QUIM.V50N1.88545
Á. Duarte-Ruiz, H. Iuele, Sergio Alejandro Torres, A. Melendez, J. Velásquez, M. Chaur, A. Duarte-Ruiz, H. Iuele, S. A. Torres-Cortés, A. Melendez, J. Velásquez, M. N. Chaur
We report on the synthesis of C60 and C70 monoadducts at room temperature through the Bingel reaction; employing acetylacetone as ligand; in presence of DBU (1,8-Diazabicyclo [5.4.0] undec-7-ene), carbon tetrabromide (CBr4), and o-dichlorobenzene. Diacetylmethane-[C60-Ih]-fullerene-[5,6] and diacetylmethane-[C70-D5h]-fullerene-[5,6] monoadducts were obtained with yields of 69% and 44%, respectively. The products were purified by column chromatography (CC, on silica gel, using hexane, carbon disulfide, and chloroform as eluents at room temperature) and characterized by Nuclear Magnetic Resonance (1H and 13C), Fourier-Transform Infrared (FT-IR) and UV-Visible spectroscopies, Matrix-assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) Mass spectrometry, Cyclic Voltammetry (CV), and Osteryoung Square Wave Voltammetry (OSWV). Both compounds showed irreversible reduction peaks controlled by diffusion, with LUMO energy levels of -3.09 eV, -3.13 eV for C60, and C70 monoadducts, respectively. These values are comparable with the -3.99 eV of PC61BM. The synthetized adducts were incorporated into inverted-type perovskite solar cells and were used as electron transporting materials (ETM) obtaining power conversion efficiencies (PCE) of 8.5% and 14.0% for the C60 and C70 monoadducts, respectively. When C60 is replaced by a lower symmetrical fullerene such as C70 an improved light absorption in the visible region is observed.
{"title":"Synthesis and characterization of C60 and C70 acetylacetone monoadducts and study of their photochemical properties for potential application in solar cells","authors":"Á. Duarte-Ruiz, H. Iuele, Sergio Alejandro Torres, A. Melendez, J. Velásquez, M. Chaur, A. Duarte-Ruiz, H. Iuele, S. A. Torres-Cortés, A. Melendez, J. Velásquez, M. N. Chaur","doi":"10.15446/REV.COLOMB.QUIM.V50N1.88545","DOIUrl":"https://doi.org/10.15446/REV.COLOMB.QUIM.V50N1.88545","url":null,"abstract":"We report on the synthesis of C60 and C70 monoadducts at room temperature through the Bingel reaction; employing acetylacetone as ligand; in presence of DBU (1,8-Diazabicyclo [5.4.0] undec-7-ene), carbon tetrabromide (CBr4), and o-dichlorobenzene. Diacetylmethane-[C60-Ih]-fullerene-[5,6] and diacetylmethane-[C70-D5h]-fullerene-[5,6] monoadducts were obtained with yields of 69% and 44%, respectively. The products were purified by column chromatography (CC, on silica gel, using hexane, carbon disulfide, and chloroform as eluents at room temperature) and characterized by Nuclear Magnetic Resonance (1H and 13C), Fourier-Transform Infrared (FT-IR) and UV-Visible spectroscopies, Matrix-assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) Mass spectrometry, Cyclic Voltammetry (CV), and Osteryoung Square Wave Voltammetry (OSWV). Both compounds showed irreversible reduction peaks controlled by diffusion, with LUMO energy levels of -3.09 eV, -3.13 eV for C60, and C70 monoadducts, respectively. These values are comparable with the -3.99 eV of PC61BM. The synthetized adducts were incorporated into inverted-type perovskite solar cells and were used as electron transporting materials (ETM) obtaining power conversion efficiencies (PCE) of 8.5% and 14.0% for the C60 and C70 monoadducts, respectively. When C60 is replaced by a lower symmetrical fullerene such as C70 an improved light absorption in the visible region is observed.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44208318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-25DOI: 10.15446/REV.COLOMB.QUIM.V50N1.89105
Gloria Smith Ramirez Forero, Wilfredo Valdivieso Quintero, J. Vega, G. Zafra, Johanna Marcela Flórez Castillo, Gloria Smith Ramirez Forero
Escherichia coli O157:H7 is a pathogenic bacterium that causes Foodborne Diseases. These diseases become a public health problem since strains resistant to different antibiotics have been found. The Ib-M1 peptide and its bioconjugate in magnetic iron oxide nanoparticles (IONP@Ib-M1) have emerged as a new antimicrobial alternative against E. coli O157:H7 and clinical isolates. The mechanism of action of Ib-M1 and IONP@Ib-M1 against E. coli O157:H7 is still unknown, therefore, the objective of this research is to identify the change in the protein profile of E. coli O157:H7 after treatment with Ib-M1 and IONP@Ib-M1, as a first step to determine the mechanism of action on the pathogen. For this, the obtaining of intracellular proteins was carried out, subsequently a two-dimensional electrophoresis was carried out to finally carry out the determination of the variability of the protein profiles. Once the protein profiles were obtained, an analysis of variance (ANOVA) was carried out. The results show the identification of proteins differentially expressed and which are involved in chemotaxis, protein synthesis and maintenance, redox processes, cell growth, amino acid transport, and translation inhibition.
{"title":"Cambios en el perfil proteico de E. coli O157:H7 frente al tratamiento con Ib-M1 e IONP@Ib-M1","authors":"Gloria Smith Ramirez Forero, Wilfredo Valdivieso Quintero, J. Vega, G. Zafra, Johanna Marcela Flórez Castillo, Gloria Smith Ramirez Forero","doi":"10.15446/REV.COLOMB.QUIM.V50N1.89105","DOIUrl":"https://doi.org/10.15446/REV.COLOMB.QUIM.V50N1.89105","url":null,"abstract":"Escherichia coli O157:H7 is a pathogenic bacterium that causes Foodborne Diseases. These diseases become a public health problem since strains resistant to different antibiotics have been found. The Ib-M1 peptide and its bioconjugate in magnetic iron oxide nanoparticles (IONP@Ib-M1) have emerged as a new antimicrobial alternative against E. coli O157:H7 and clinical isolates. The mechanism of action of Ib-M1 and IONP@Ib-M1 against E. coli O157:H7 is still unknown, therefore, the objective of this research is to identify the change in the protein profile of E. coli O157:H7 after treatment with Ib-M1 and IONP@Ib-M1, as a first step to determine the mechanism of action on the pathogen. For this, the obtaining of intracellular proteins was carried out, subsequently a two-dimensional electrophoresis was carried out to finally carry out the determination of the variability of the protein profiles. Once the protein profiles were obtained, an analysis of variance (ANOVA) was carried out. The results show the identification of proteins differentially expressed and which are involved in chemotaxis, protein synthesis and maintenance, redox processes, cell growth, amino acid transport, and translation inhibition.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"50 1","pages":"3-12"},"PeriodicalIF":0.8,"publicationDate":"2021-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48292270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-03-25DOI: 10.15446/REV.COLOMB.QUIM.V50N1.90134
Roberto Urcuyo Solórzano, Karla Vanessa Cordero Solano, Diego Andrés Gonzalez Flores
16 years after the great discovery of graphene, the focus and attention are again on this material after the report of its superconducting behavior depending on the stacking of its layers. The graphene has not only been related to superconductivity but has also been related to a wide diversity of applications, in very diverse disciplines. Among them, we can mention: Opto-electronic materials, electrodes for catalysis, devices for waste-water treatment, biosensors, batteries, and solar cells. This has caused a large number of research groups to be interested not only in the study of its properties, but also in the research of new synthetic methods that can be scaled to industrial levels, without losing its electronic and mechanical properties. Despite numerous studies and resources invested in graphene, not all applications have become a reality, some of the most successful are shown in this review.
{"title":"Perspectivas y aplicaciones reales del grafeno después de 16 años de su descubrimiento","authors":"Roberto Urcuyo Solórzano, Karla Vanessa Cordero Solano, Diego Andrés Gonzalez Flores","doi":"10.15446/REV.COLOMB.QUIM.V50N1.90134","DOIUrl":"https://doi.org/10.15446/REV.COLOMB.QUIM.V50N1.90134","url":null,"abstract":"16 years after the great discovery of graphene, the focus and attention are again on this material after the report of its superconducting behavior depending on the stacking of its layers. The graphene has not only been related to superconductivity but has also been related to a wide diversity of applications, in very diverse disciplines. Among them, we can mention: Opto-electronic materials, electrodes for catalysis, devices for waste-water treatment, biosensors, batteries, and solar cells. This has caused a large number of research groups to be interested not only in the study of its properties, but also in the research of new synthetic methods that can be scaled to industrial levels, without losing its electronic and mechanical properties. Despite numerous studies and resources invested in graphene, not all applications have become a reality, some of the most successful are shown in this review.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"50 1","pages":"51-85"},"PeriodicalIF":0.8,"publicationDate":"2021-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42638548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.15446/rev.colomb.quim.v50n2.90293
Josemário Santana Bonsucesso, Andreia Santos do Nascimento, Antônio Leandro da Silva Conceição, Carlos Alfredo Lopes de Carvalho, Fábio de Souza Dias
This study evaluates the efficiency of acid extraction and total digestion to determine the presence of metals in geopropolis produced by the stingless bee Melipona scutellaris. Geopropolis samples were collected at five meliponaries in the city and in the metropolitan region of Salvador, Bahia State, Brazil. The sample treatment methods comprised acid extraction and total digestion. The Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) technique was used to quantify Cd, Cu, Cr, Pb, and Zn. Geopropolis samples submitted to both digestion methods showed statistical differences. For both methods, Cr and Zn showed the highest concentrations, while those of Cd were the lowest. The Cr concentration for determination by total digestion was 37.53 mg/kg, while for acid extraction it was 32.90 mg/kg. For Zn, the concentration was 17.65 mg/kg and 8.85 mg/kg for total digestion and acid extraction, respectively. The total digestion method showed the highest concentrations of the metals evaluated; however, acid extraction (USEPA 3050b) is a more straightforward procedure for metal evaluation in geopropolis samples and presented values that support the use of geopropolis as a bioindicator. The acid extraction method USEPA 3050b, in combination with detection using ICP OES, showed efficiency in analyses carried out to determine metals in geopropolis.
{"title":"Efficiency of two digestion methods in determining the presence of metals (Cd, Cu, Cr, Pb and Zn) in geopropolis produced by Melipona scutellaris","authors":"Josemário Santana Bonsucesso, Andreia Santos do Nascimento, Antônio Leandro da Silva Conceição, Carlos Alfredo Lopes de Carvalho, Fábio de Souza Dias","doi":"10.15446/rev.colomb.quim.v50n2.90293","DOIUrl":"https://doi.org/10.15446/rev.colomb.quim.v50n2.90293","url":null,"abstract":"This study evaluates the efficiency of acid extraction and total digestion to determine the presence of metals in geopropolis produced by the stingless bee Melipona scutellaris. Geopropolis samples were collected at five meliponaries in the city and in the metropolitan region of Salvador, Bahia State, Brazil. The sample treatment methods comprised acid extraction and total digestion. The Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) technique was used to quantify Cd, Cu, Cr, Pb, and Zn. Geopropolis samples submitted to both digestion methods showed statistical differences. For both methods, Cr and Zn showed the highest concentrations, while those of Cd were the lowest. The Cr concentration for determination by total digestion was 37.53 mg/kg, while for acid extraction it was 32.90 mg/kg. For Zn, the concentration was 17.65 mg/kg and 8.85 mg/kg for total digestion and acid extraction, respectively. The total digestion method showed the highest concentrations of the metals evaluated; however, acid extraction (USEPA 3050b) is a more straightforward procedure for metal evaluation in geopropolis samples and presented values that support the use of geopropolis as a bioindicator. The acid extraction method USEPA 3050b, in combination with detection using ICP OES, showed efficiency in analyses carried out to determine metals in geopropolis.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"1 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67057014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.15446/rcq.v49n3.84882
Rosa Leonor González Díaz, Flor del Carmen Rodríguez Gómez, Celso Cortés Romero
Fructans are carbohydrates of diverse chemical structure that are distributed in different taxa. In plants, in addition to be an important source of carbon, they have been associated with tolerance to different types of stress. The biosynthesis of these compounds is carried out by the action of enzymes called fructosyltransferases, while their degradation is mediated by fructan exohydrolases, both types are part of the 32 family of glycosidic hydrolase enzymes. Fructan exohydrolases are exo-enzymes that sequentially release terminal fructose residues from fructans to make them available as carbon sources for different cellular processes or as signaling molecules. In this review, a description is made of fructans, y of fructosyl exohydrolases in some plants important for human consumption or for industrial use, such as the Agave genus, specifically in A. tequilana. We conclude that the study of fructan exohydrolases in agaves could be useful in various biotechnological applications, for example, in the hydrolysis of undigested fructan structures during the agave cooking stage in the tequila production process. However, the first step is to determinate the enzymatic activity in which they are involved, for its posterior inclusion in biotechnology processes.
{"title":"Exohidrolasas fructosílicas y su importancia en el metabolismo de fructanos en Agave tequilana Weber var. azul","authors":"Rosa Leonor González Díaz, Flor del Carmen Rodríguez Gómez, Celso Cortés Romero","doi":"10.15446/rcq.v49n3.84882","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.84882","url":null,"abstract":"Fructans are carbohydrates of diverse chemical structure that are distributed in different taxa. In plants, in addition to be an important source of carbon, they have been associated with tolerance to different types of stress. The biosynthesis of these compounds is carried out by the action of enzymes called fructosyltransferases, while their degradation is mediated by fructan exohydrolases, both types are part of the 32 family of glycosidic hydrolase enzymes. Fructan exohydrolases are exo-enzymes that sequentially release terminal fructose residues from fructans to make them available as carbon sources for different cellular processes or as signaling molecules. In this review, a description is made of fructans, y of fructosyl exohydrolases in some plants important for human consumption or for industrial use, such as the Agave genus, specifically in A. tequilana. We conclude that the study of fructan exohydrolases in agaves could be useful in various biotechnological applications, for example, in the hydrolysis of undigested fructan structures during the agave cooking stage in the tequila production process. However, the first step is to determinate the enzymatic activity in which they are involved, for its posterior inclusion in biotechnology processes.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"49 1","pages":"3-12"},"PeriodicalIF":0.8,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.15446/rcq.v49n3.84882","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48470789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-06DOI: 10.15446/rcq.v49n3.84082
Sergio M. Pico-Hernández, Cristian J. Murillo-Méndez, L. López-Giraldo
Polyphenol Extracts (PE) hold antioxidant properties, which might be related to positive effects on human health. It has been stated that PE, obtained from cocoa beans, contain fractions of flavan-3-ols with different degrees of polymerization (DP). However, it is unknown which of the fractions or their mixture drives the best antioxidant activity. This paper reports the study conducted to elucidate the role of each fraction (with different DP) on Antioxidant Capacity (AC). First, the process of extraction and separation of polyphenols’ fractions in cocoa beans was executed; afterward, AC was determined for each fraction individually and their combinations (monomers, dimers and oligomers). Solid-liquid extraction was made by using a 50% (v/v) ethanol solution and a mass:solvent ratio of 1:120 in an ultrasound bath. PE were separated into monomers, dimers, and oligomers by HPLC using a semipreparative column. The results obtained show that PE contain 95.35, 7.45, and 21.75 mg EE (epicatechin equivalents) / g ds of monomers, dimers, and oligomers, respectively. Finally, the AC of each fraction was evaluated using a complete cubic model mix design. According to the results, the best AC was obtained for dimers. However, when monomers, dimers and oligomers were mixed, an antagonistic effect on AC was observed.
{"title":"Extraction, separation, and evaluation of antioxidant effect of the different fractions of polyphenols from cocoa beans","authors":"Sergio M. Pico-Hernández, Cristian J. Murillo-Méndez, L. López-Giraldo","doi":"10.15446/rcq.v49n3.84082","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.84082","url":null,"abstract":"Polyphenol Extracts (PE) hold antioxidant properties, which might be related to positive effects on human health. It has been stated that PE, obtained from cocoa beans, contain fractions of flavan-3-ols with different degrees of polymerization (DP). However, it is unknown which of the fractions or their mixture drives the best antioxidant activity. This paper reports the study conducted to elucidate the role of each fraction (with different DP) on Antioxidant Capacity (AC). First, the process of extraction and separation of polyphenols’ fractions in cocoa beans was executed; afterward, AC was determined for each fraction individually and their combinations (monomers, dimers and oligomers). Solid-liquid extraction was made by using a 50% (v/v) ethanol solution and a mass:solvent ratio of 1:120 in an ultrasound bath. PE were separated into monomers, dimers, and oligomers by HPLC using a semipreparative column. The results obtained show that PE contain 95.35, 7.45, and 21.75 mg EE (epicatechin equivalents) / g ds of monomers, dimers, and oligomers, respectively. Finally, the AC of each fraction was evaluated using a complete cubic model mix design. According to the results, the best AC was obtained for dimers. However, when monomers, dimers and oligomers were mixed, an antagonistic effect on AC was observed.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"49 1","pages":"19-27"},"PeriodicalIF":0.8,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41741828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-06DOI: 10.15446/rcq.v49n3.87159
Alejandra Guadalupe Villegas Pañeda, M. T. Ramírez Apán
The protoanemonin, a natural furanone, was synthesized from (Z)-4-bromo-5-(bromomethylene)-furan-2(5H)-one by a reductive dehalogenation reaction with zinc. The 5-(dibromomethylene)-2(5H)-furanone and (E)-5-(bromomethylene)-2(5H)-furanone were also synthetized from levulinic acid bromination and acid promoted cyclization. The antiproliferative activity of all synthesized compounds against the human cancer cell lines PC-3 (prostate) and U-251 (glioblastoma) was investigated. The results showed that all the obtained furanones are more active than the reference drug cisplatin, with IC50 values in the range of 0.31 ± 0.02 to 7.30 ± 0.08 μM. However, (E)-5-(bromomethylene)-2(5H)-furanone, with a bromine atom in the double bond, was the most active, and demonstrated to be about 25-fold more active than the reference drug cisplatin.
{"title":"Synthesis and cytotoxic evaluation of protoanemonin and three brominated derivatives","authors":"Alejandra Guadalupe Villegas Pañeda, M. T. Ramírez Apán","doi":"10.15446/rcq.v49n3.87159","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.87159","url":null,"abstract":"The protoanemonin, a natural furanone, was synthesized from (Z)-4-bromo-5-(bromomethylene)-furan-2(5H)-one by a reductive dehalogenation reaction with zinc. The 5-(dibromomethylene)-2(5H)-furanone and (E)-5-(bromomethylene)-2(5H)-furanone were also synthetized from levulinic acid bromination and acid promoted cyclization. The antiproliferative activity of all synthesized compounds against the human cancer cell lines PC-3 (prostate) and U-251 (glioblastoma) was investigated. The results showed that all the obtained furanones are more active than the reference drug cisplatin, with IC50 values in the range of 0.31 ± 0.02 to 7.30 ± 0.08 μM. However, (E)-5-(bromomethylene)-2(5H)-furanone, with a bromine atom in the double bond, was the most active, and demonstrated to be about 25-fold more active than the reference drug cisplatin.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"49 1","pages":"13-18"},"PeriodicalIF":0.8,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46142565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-06DOI: 10.15446/rcq.v49n3.85301
César A. Sierra, L. Perez, A. Garzón, J. Hinestroza, Diana Sinuco
After an internal conflict that lasted over half a century, the detection and removal of antipersonnel landmines in Colombia have become cumbersome challenges. Antipersonnel landmines remain scattered in Colombia and with a considerable impact on the central-western region. Most of these devices are handmade (therefore, they can also be classified as improvised explosive devices) and composed of ammonium nitrate and fossil fuel blend, a mixture known as ANFO. Due to several unique factors, including concealment tactics and non-conventional manufacturing techniques employed by guerrilla fighters, the most efficient method for the detection of ANFO-based antipersonnel landmines is the use of trained canines. This review aims at describing the current chemical strategies used in the detection of ANFO-based antipersonnel landmines. First, a detailed description of the different techniques used in the detection of explosives is made. Then, all the strategies reported in the world for antipersonnel landmines detection are described. Finally, the importance of the use of canines for antipersonnel landmines detection is explained.
{"title":"Detection of antipersonnel landmines containing ANFO-based explosive: A review","authors":"César A. Sierra, L. Perez, A. Garzón, J. Hinestroza, Diana Sinuco","doi":"10.15446/rcq.v49n3.85301","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.85301","url":null,"abstract":"After an internal conflict that lasted over half a century, the detection and removal of antipersonnel landmines in Colombia have become cumbersome challenges. Antipersonnel landmines remain scattered in Colombia and with a considerable impact on the central-western region. Most of these devices are handmade (therefore, they can also be classified as improvised explosive devices) and composed of ammonium nitrate and fossil fuel blend, a mixture known as ANFO. Due to several unique factors, including concealment tactics and non-conventional manufacturing techniques employed by guerrilla fighters, the most efficient method for the detection of ANFO-based antipersonnel landmines is the use of trained canines. This review aims at describing the current chemical strategies used in the detection of ANFO-based antipersonnel landmines. First, a detailed description of the different techniques used in the detection of explosives is made. Then, all the strategies reported in the world for antipersonnel landmines detection are described. Finally, the importance of the use of canines for antipersonnel landmines detection is explained.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":" ","pages":""},"PeriodicalIF":0.8,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48564347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-06DOI: 10.15446/rcq.v49n3.85823
Carmencita Del Rocio Lavado Meza, María del Rosario Sun Kou, Humberto Dax Bonilla Mancilla, Tracy Kate Castro Arroyo
The removal of lead from aqueous solutions by the biomass of prickly pear cladodes (BCT), a species found in abundance in the Sierra region in Peru, was investigated. The physical and chemical properties of BCT were determined by FTIR and SEM/EDX techniques. The FTIR analysis confirmed the presence of –OH, C–O–C, C=O and –NH2 groups which would interact with the metal. The SEM micrograph revealed that the surface morphology of the BCT shows adequate porosity for biosorption. In a discontinuous system, the highest biosorption capacity (qe) was obtained with a BCT mass/volume ratio of 4 g/L, pH 4.5 and 1 h of contact time. Biosorption followed a pseudo-second order kinetic model and the intraparticle diffusion process was the main factor controlling speed. Data at equilibrium were correlated using five models (Langmuir, Freundlich, Temkin, DR, and Redlich-Peterson) and were better fitted to the Langmuir model, which would indicate that the process is carried out in energetically homogeneous active centers, the value of qe maximum was 50.25 mg/g. The results obtained demonstrate that BCT can be used as an efficient biosorbent for the treatment of waters contaminated with Pb (II).
研究了仙人掌枝(BCT)的生物量对水溶液中铅的去除作用，仙人掌枝是秘鲁塞拉地区丰富的一种物种。采用FTIR和SEM/EDX技术对BCT的理化性质进行了表征。FTIR分析证实了-OH, C - O - C, C=O和-NH2基团的存在，这些基团会与金属相互作用。SEM显微照片显示，BCT的表面形貌具有足够的孔隙度进行生物吸附。在不连续体系中，当BCT质量/体积比为4 g/L、pH为4.5、接触时间为1 h时，生物吸附量(qe)最高。生物吸附遵循准二级动力学模型，颗粒内扩散过程是控制吸附速度的主要因素。平衡态数据采用Langmuir、Freundlich、Temkin、DR和Redlich-Peterson五种模型进行关联，结果表明Langmuir模型拟合较好，表明该过程在能量均相的活性中心进行，qe最大值为50.25 mg/g。实验结果表明，BCT可作为一种高效的生物吸附剂处理含铅水体。
{"title":"Biosorción de plomo (II) en solución acuosa con biomasa de los cladodios de la tuna (Opuntia ficus indica)","authors":"Carmencita Del Rocio Lavado Meza, María del Rosario Sun Kou, Humberto Dax Bonilla Mancilla, Tracy Kate Castro Arroyo","doi":"10.15446/rcq.v49n3.85823","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.85823","url":null,"abstract":"The removal of lead from aqueous solutions by the biomass of prickly pear cladodes (BCT), a species found in abundance in the Sierra region in Peru, was investigated. The physical and chemical properties of BCT were determined by FTIR and SEM/EDX techniques. The FTIR analysis confirmed the presence of –OH, C–O–C, C=O and –NH2 groups which would interact with the metal. The SEM micrograph revealed that the surface morphology of the BCT shows adequate porosity for biosorption. In a discontinuous system, the highest biosorption capacity (qe) was obtained with a BCT mass/volume ratio of 4 g/L, pH 4.5 and 1 h of contact time. Biosorption followed a pseudo-second order kinetic model and the intraparticle diffusion process was the main factor controlling speed. Data at equilibrium were correlated using five models (Langmuir, Freundlich, Temkin, DR, and Redlich-Peterson) and were better fitted to the Langmuir model, which would indicate that the process is carried out in energetically homogeneous active centers, the value of qe maximum was 50.25 mg/g. The results obtained demonstrate that BCT can be used as an efficient biosorbent for the treatment of waters contaminated with Pb (II).","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"49 1","pages":"36-46"},"PeriodicalIF":0.8,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.15446/rcq.v49n3.85823","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42372656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-06DOI: 10.15446/rcq.v49n3.85900
Violeta Maricela Dalgo Flores, Gabriela Cristina Chango-Lescano, John G. Vera-Luzuriaga
Magnetite magnetic nanoparticles (MNP) exhibit superparamagnetic behavior, which gives them important properties such as low coercive field, easy surface modification and acceptable levels of magnetization, making them useful in separation techniques. However, few studies have experimented the interactions they have with magnetic fields. For this reason, in this research, the influence of an oscillating magnetic field (CMO) on polymeric monolithic columns containing vinylized magnetite magnetic nanoparticles (VMNP) for capillary liquid chromatography was studied. For this, MNP were synthesized, by co-precipitation of iron salts. The preparation of the polymeric monolithic columns was carried out by the copolymerization method and the subsequent aggregation of VMNP. Taking advantage of the magnetic properties of the MNPs, the influence of various parameters (resonance frequency, intensity, and exposure time) of an CMO applied to the synthesized columns was studied. As a result, a better separation of the sample according to the measured parameters was obtained. Thus, achieving a column resolution (Rs) of 1.35. The morphological properties of monolithic columns were evaluated using scanning electron microscopy (SEM). The results of the chromatographic properties showed that the best separation of the sample of alkylbenzenes (ABS) in cLC occurs under conditions of 5.5 kHz and 10 min of exposure in the CMO. This study constitutes the first application in chromatographic separation techniques for future nanotechnology research.
{"title":"Influencia de un campo magnético oscilante en columnas poliméricas con nanopartículas magnéticas (ARTÍCULO RETRACTADO)","authors":"Violeta Maricela Dalgo Flores, Gabriela Cristina Chango-Lescano, John G. Vera-Luzuriaga","doi":"10.15446/rcq.v49n3.85900","DOIUrl":"https://doi.org/10.15446/rcq.v49n3.85900","url":null,"abstract":"Magnetite magnetic nanoparticles (MNP) exhibit superparamagnetic behavior, which gives them important properties such as low coercive field, easy surface modification and acceptable levels of magnetization, making them useful in separation techniques. However, few studies have experimented the interactions they have with magnetic fields. For this reason, in this research, the influence of an oscillating magnetic field (CMO) on polymeric monolithic columns containing vinylized magnetite magnetic nanoparticles (VMNP) for capillary liquid chromatography was studied. For this, MNP were synthesized, by co-precipitation of iron salts. The preparation of the polymeric monolithic columns was carried out by the copolymerization method and the subsequent aggregation of VMNP. Taking advantage of the magnetic properties of the MNPs, the influence of various parameters (resonance frequency, intensity, and exposure time) of an CMO applied to the synthesized columns was studied. As a result, a better separation of the sample according to the measured parameters was obtained. Thus, achieving a column resolution (Rs) of 1.35. The morphological properties of monolithic columns were evaluated using scanning electron microscopy (SEM). The results of the chromatographic properties showed that the best separation of the sample of alkylbenzenes (ABS) in cLC occurs under conditions of 5.5 kHz and 10 min of exposure in the CMO. This study constitutes the first application in chromatographic separation techniques for future nanotechnology research.","PeriodicalId":43662,"journal":{"name":"Revista Colombiana de Quimica","volume":"49 1","pages":"28-35"},"PeriodicalIF":0.8,"publicationDate":"2020-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45401293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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