The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Laura Delgadomoreno - One of the best experts on this subject based on the ideXlab platform.
-
contribution by different organic fractions to Triazines sorption in calcaric regosol amended with raw and biotransformed olive cake
Journal of Hazardous Materials, 2010Co-Authors: Laura Delgadomoreno, Aranzazu Pena, G AlmenbdrosAbstract:Abstract A soil, olive cake, compost and vermicompost of olive cake, were subjected to sequential laboratory extraction to progressively remove water-soluble, lipid and alkali-soluble (humic-type) fractions. Sorption experiments with Triazines were carried out with non-amended and amended soil and with soil residues in the intermediate stages during the laboratory removal of the different organic fractions. Herbicide sorption in soil amended with olive cake was between two and three times higher than sorption in composted substrates. In non-amended soil, the removal of humic and fulvic acids led to a decrease of Triazines sorption indicating the importance of these fractions in the sorption of these pesticides. The greater Triazines sorption in soil amended with olive cake could be associated with the high concentration of water-soluble substances. In contrast, olive cake lipids did not favour the sorption of the more hydrophobic herbicides as indicated by the fact that the sorbed amount increased 30–40% when this fraction was removed. No significant ( P > 0.05) differences in K oc values were found in soils amended with compost and vermicompost in the course of the progressive removal of the different organic fractions, indicating triazine sorption was related more with the total amount of organic matter than with its chemical composition.
-
design of experiments in environmental chemistry studies example of the extraction of Triazines from soil after olive cake amendment
Journal of Hazardous Materials, 2009Co-Authors: Laura Delgadomoreno, Aranzazu Pena, M D MingoranceAbstract:Abstract The disposal of natural, composted and vermicomposted olive cake for modifying the fate of triazine herbicides with different physicochemical properties (terbuthylazine, cyanazine, simazine and prometryn) has been tested. Experimental design (surface response methodology plus desirability function) to multicriteria optimization was carried out to evaluate both dose and type of amendment to retain the cited analytes and to develop two simple and low cost analytical methods for extracting Triazines from soil. From a methodological point of view, classical and D-optimal designs were employed depending on the problem. Thus, the best combination of soil amount and solvent ratio, the most important parameters affecting triazine extraction from soil, was looked for by means of Central Composite Designs. Under the optimized conditions, the range of Triazines recovery was 75–85% for shaking extraction and 87–107% for ultrasonic extraction. Regarding the amendment assay, D-optimal design was selected to keep the reliability of the estimations. Natural olive cake added to the soil at a high dose (8%) reduced herbicide recovery to ca. 50–60% for terbuthylazine, prometryn and simazine, while cyanazine recovery was negligible. Design of experiment provides an efficient working strategy to explore those conditions which ensure the optimum or target value of several responses evaluated simultaneously.
-
compost and vermicompost of olive cake to bioremediate Triazines contaminated soil
Science of The Total Environment, 2009Co-Authors: Laura Delgadomoreno, Aranzazu PenaAbstract:The use of organic amendments to bioremediate potential organic pollutants of soil and water has become an increasingly relevant issue in the last years. This strategy has been applied to four triazine herbicides in a typical calcareous agricultural soil of the Mediterranean area. The soil was amended with olive cake, compost and vermicompost of olive cake at rates four times higher than the agronomic dose in order to stimulate biodegradation of simazine, terbuthylazine, cyanazine and prometryn, added in a mixture to the soils. Degradation studies were carried out in sterile and microbially active soil to evaluate the effect of the chemical and biological degradation of Triazines. The residual herbicide concentrations at the end of the degradation assay showed no significant differences between non amended and amended soil. However, the addition of compost and vermicompost enhanced the biological degradation rate of Triazines during the first week of incubation, with half-lives ranging form 5 to 18 days for the amended soils, whilst negligible degradation occurred in non-amended soil during this period. In contrast, olive cake did not significantly modify the degradation of Triazines in spite that the addition of this amendment to soil resulted in the highest dehidrogenase activity values. In all the substrates, degradation of cyanazine and prometryn was faster (between 1.5 and two times higher) than those of terbuthylazine and simazine, without significant relationship with sorption parameters. The first order kinetic equation satisfactorily explained the experimental data for all Triazines. A biphasic model, such as that proposed by Hoerl, was better to predict the very rapid Triazines decay during the first week of incubation in soil amended with compost and vermicompost.
Prem M S Chauhan - One of the best experts on this subject based on the ideXlab platform.
-
synthesis and biological evaluation of new 1 2 4 triazino 5 6 b indol 3 ylthio 1 3 5 Triazines and 1 2 4 triazino 5 6 b indol 3 ylthio pyrimidines against leishmania donovani
European Journal of Medicinal Chemistry, 2010Co-Authors: Leena Gupta, Naresh Sunduru, Aditya Verma, Saumya Srivastava, Suman Gupta, Neena Goyal, Prem M S ChauhanAbstract:Abstract A series of [1,2,4]triazino[5,6-b]indol-3-ylthio-1,3,5-Triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-pyrimidines were synthesized and screened for their in vitro antileishmanial activity against Leishmania donovani. Among all, 8 compounds have shown more than 90% inhibition against promastigotes and IC50 in the range of 4.01–57.78 μM against amastigotes. Compound 5, a triazino[5,6-b]indol-3-ylthio-1,3,5-triazine derivative was found to be the most active and least toxic with 20- & 10-fold more selectivity (S.I. = 56.61) as compared to that of standard drugs pentamidine and sodium stibogluconate (SSG), respectively.
Aranzazu Pena - One of the best experts on this subject based on the ideXlab platform.
-
contribution by different organic fractions to Triazines sorption in calcaric regosol amended with raw and biotransformed olive cake
Journal of Hazardous Materials, 2010Co-Authors: Laura Delgadomoreno, Aranzazu Pena, G AlmenbdrosAbstract:Abstract A soil, olive cake, compost and vermicompost of olive cake, were subjected to sequential laboratory extraction to progressively remove water-soluble, lipid and alkali-soluble (humic-type) fractions. Sorption experiments with Triazines were carried out with non-amended and amended soil and with soil residues in the intermediate stages during the laboratory removal of the different organic fractions. Herbicide sorption in soil amended with olive cake was between two and three times higher than sorption in composted substrates. In non-amended soil, the removal of humic and fulvic acids led to a decrease of Triazines sorption indicating the importance of these fractions in the sorption of these pesticides. The greater Triazines sorption in soil amended with olive cake could be associated with the high concentration of water-soluble substances. In contrast, olive cake lipids did not favour the sorption of the more hydrophobic herbicides as indicated by the fact that the sorbed amount increased 30–40% when this fraction was removed. No significant ( P > 0.05) differences in K oc values were found in soils amended with compost and vermicompost in the course of the progressive removal of the different organic fractions, indicating triazine sorption was related more with the total amount of organic matter than with its chemical composition.
-
design of experiments in environmental chemistry studies example of the extraction of Triazines from soil after olive cake amendment
Journal of Hazardous Materials, 2009Co-Authors: Laura Delgadomoreno, Aranzazu Pena, M D MingoranceAbstract:Abstract The disposal of natural, composted and vermicomposted olive cake for modifying the fate of triazine herbicides with different physicochemical properties (terbuthylazine, cyanazine, simazine and prometryn) has been tested. Experimental design (surface response methodology plus desirability function) to multicriteria optimization was carried out to evaluate both dose and type of amendment to retain the cited analytes and to develop two simple and low cost analytical methods for extracting Triazines from soil. From a methodological point of view, classical and D-optimal designs were employed depending on the problem. Thus, the best combination of soil amount and solvent ratio, the most important parameters affecting triazine extraction from soil, was looked for by means of Central Composite Designs. Under the optimized conditions, the range of Triazines recovery was 75–85% for shaking extraction and 87–107% for ultrasonic extraction. Regarding the amendment assay, D-optimal design was selected to keep the reliability of the estimations. Natural olive cake added to the soil at a high dose (8%) reduced herbicide recovery to ca. 50–60% for terbuthylazine, prometryn and simazine, while cyanazine recovery was negligible. Design of experiment provides an efficient working strategy to explore those conditions which ensure the optimum or target value of several responses evaluated simultaneously.
-
compost and vermicompost of olive cake to bioremediate Triazines contaminated soil
Science of The Total Environment, 2009Co-Authors: Laura Delgadomoreno, Aranzazu PenaAbstract:The use of organic amendments to bioremediate potential organic pollutants of soil and water has become an increasingly relevant issue in the last years. This strategy has been applied to four triazine herbicides in a typical calcareous agricultural soil of the Mediterranean area. The soil was amended with olive cake, compost and vermicompost of olive cake at rates four times higher than the agronomic dose in order to stimulate biodegradation of simazine, terbuthylazine, cyanazine and prometryn, added in a mixture to the soils. Degradation studies were carried out in sterile and microbially active soil to evaluate the effect of the chemical and biological degradation of Triazines. The residual herbicide concentrations at the end of the degradation assay showed no significant differences between non amended and amended soil. However, the addition of compost and vermicompost enhanced the biological degradation rate of Triazines during the first week of incubation, with half-lives ranging form 5 to 18 days for the amended soils, whilst negligible degradation occurred in non-amended soil during this period. In contrast, olive cake did not significantly modify the degradation of Triazines in spite that the addition of this amendment to soil resulted in the highest dehidrogenase activity values. In all the substrates, degradation of cyanazine and prometryn was faster (between 1.5 and two times higher) than those of terbuthylazine and simazine, without significant relationship with sorption parameters. The first order kinetic equation satisfactorily explained the experimental data for all Triazines. A biphasic model, such as that proposed by Hoerl, was better to predict the very rapid Triazines decay during the first week of incubation in soil amended with compost and vermicompost.
Bernard Rondeau - One of the best experts on this subject based on the ideXlab platform.
-
multiresidue methods using solid phase extraction techniques for monitoring priority pesticides including Triazines and degradation products in ground and surface waters
Journal of Chromatography A, 2000Co-Authors: Hassan Sabik, Roger Jeannot, Bernard RondeauAbstract:The review describes the use of solid-phase extraction (SPE) techniques for monitoring priority pesticides in ground and surface waters. The focus is on triazine herbicides and their degradation products. Data concerning the fate, occurrence, properties and extraction of Triazines and their degradation products using different SPE techniques are tabulated and discussed.
Leena Gupta - One of the best experts on this subject based on the ideXlab platform.
-
synthesis and biological evaluation of new 1 2 4 triazino 5 6 b indol 3 ylthio 1 3 5 Triazines and 1 2 4 triazino 5 6 b indol 3 ylthio pyrimidines against leishmania donovani
European Journal of Medicinal Chemistry, 2010Co-Authors: Leena Gupta, Naresh Sunduru, Aditya Verma, Saumya Srivastava, Suman Gupta, Neena Goyal, Prem M S ChauhanAbstract:Abstract A series of [1,2,4]triazino[5,6-b]indol-3-ylthio-1,3,5-Triazines and [1,2,4]triazino[5,6-b]indol-3-ylthio-pyrimidines were synthesized and screened for their in vitro antileishmanial activity against Leishmania donovani. Among all, 8 compounds have shown more than 90% inhibition against promastigotes and IC50 in the range of 4.01–57.78 μM against amastigotes. Compound 5, a triazino[5,6-b]indol-3-ylthio-1,3,5-triazine derivative was found to be the most active and least toxic with 20- & 10-fold more selectivity (S.I. = 56.61) as compared to that of standard drugs pentamidine and sodium stibogluconate (SSG), respectively.
