Construcción y evaluación de un electrodo potenciométrico selectivo a iones Hg(II) utilizando nuevos ionóforos
This thesis describes the synthesis of chemicals suitable for using as ionophores in polymeric membranes for ion-selective electrodes for mercury (II). The synthesis is based on the introduction of an alkyl linear group into the compound O, O’- (2,2’-biphenylene) dithiophosphate potassium (arrow com...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | México |
| Institución: | Universidad Autónoma Metropolitana |
| Repositorio: | Repositorio Institucional de la UAM Iztapalapa |
| Idioma: | español |
| OAI Identifier: | oai:bindani.izt.uam.mx:cv43nw97p |
| Acceso en línea: | https://doi.org/10.24275/uami.cv43nw97p |
| Access Level: | acceso abierto |
| Palabra clave: | info:eu-repo/classification/LEM/Electroquímica -- Sensores info:eu-repo/classification/LEM/Electrochemical analysis info:eu-repo/classification/LEM/Electrodos selectivos de iones info:eu-repo/classification/LEM/Membranes (Technology) info:eu-repo/classification/LEM/Electrochemistry -- Detectors info:eu-repo/classification/LEM/Agua -- Contaminación info:eu-repo/classification/LEM/Análisis electroquímico info:eu-repo/classification/LEM/Electrodes, Ion selective info:eu-repo/classification/LEM/Membranas (Tecnología) info:eu-repo/classification/LEM/Water -- Pollution info:eu-repo/classification/cti/2 |
| Sumario: | This thesis describes the synthesis of chemicals suitable for using as ionophores in polymeric membranes for ion-selective electrodes for mercury (II). The synthesis is based on the introduction of an alkyl linear group into the compound O, O’- (2,2’-biphenylene) dithiophosphate potassium (arrow compound). Thus the synthesis the series of five ionophores CH3(CH2)nS2P(OC6H4)2 (n = 0–4) was achieved, through increasing the chain from methyl to n-pentyl. Also, the potentiometric studies of a novel solid contact ion-selective electrode based on a new dithiophosphored ionophore O,O’-(2.2’-biphenylene) pentyl dithiophosphate (PenDTF) are presented. The ISE has a high selectivity to Hg(II) in the presence of divalent ions, the electrode showed a good Nernstian response to Hg (II) (33.81 ± 1.24) mV década-1 over a wide range of concentrations (5.35 x 10-7 − 1.00 x 10-2 ) mol L-1 , the detection limit was (4.24 x 10-7 ± 2.48 x 10-7 ) mol L-1 . Due to its design the electrode can be used for several experiments renewing the contact surface with sandpaper without observing significant deviation in its response with a coefficient of variation less than 3% and could be tested in the 0-5 pH range, the electrode was successfully used as an indicator electrode for the potentiometric titration of Hg(II) ions with EDTA. The construction of a new ion selective electrode (ISE) for the potentiometric determination of mercury ions is presented, using a support matrix and carbon-epoxy composite with a polymer matrix of ionophore / plasticizer / PVC / NaTPB. This sensor allows continuous measurement of mercury at nanomolar levels in a wide concentration range (1.0 x 10-9 to 1.0 x 10-1 ) mol L-1 , with a limit of detection (9.1 ± 0.8) x 10-10 mol L-1 and a Nernstian response (29.8 ± 0.4) mV decade-1 . The ISE trus characterized can be used in the 0-6 pH range, also has a high selectivity for mercury ions is presented, using a support matrix and carbon-epoxy composite with a polymer matrix of ionophore / plasticizer / PVC / NaTPB. This sensor allows continuous measurement of mercury at nanomolar levels in a wide concentration range (1.0 x 10-9 to 1.0 x 10-1 ) mol L-1 , with a limit of detection (9.1 ± 0.8) x 10-10 mol L-1 and a Nernstian response (29.8 ± 0.4) mV decade-1 . The ISE trus characterized can be used in the 0-6 pH range, also has a high selectivity for mercury ions even in the presence of interfering ions and can be used as an indicator electrode for potentiometric titration of mercury with EDTA since it is comparable to commercial electrodes of the same class. |
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