A new generation of cyanide ion-selective membranes for flow injection application. Part III. A simple approach to the determination of toxic metal-cyanide complexes without preliminary separation
| creativework.keywords | Ag2 + δSe1 - xTex and Ag2 + δSe FIP-detectors, Bound cyanide electrochemical release, Cyanide speciation, Ligand exchange, WAD cyanide determination | |
| creativework.publisher | Elsevier | en |
| dc.contributor.author | Surleva A. | |
| dc.contributor.author | Neshkova M. | |
| dc.date.accessioned | 2024-07-10T14:27:03Z | |
| dc.date.accessioned | 2024-07-10T14:47:24Z | |
| dc.date.available | 2024-07-10T14:27:03Z | |
| dc.date.available | 2024-07-10T14:47:24Z | |
| dc.date.issued | 2008-08-15 | |
| dc.description.abstract | A new flow injection approach to total weak acid-dissociable (WAD) metal-cyanide complexes is proposed, which eliminates the need of a separation step (such as gas diffusion or pervaporation) prior to the detection. The cornerstone of the new methodology is based on the highly selective flow-injection potentiometric detection (FIPD) system that makes use of thin-layer electroplated silver chalcogenide ion-selective membranes of non-trivial composition and surface morphology: Ag2 + δSe1 - xTex and Ag2 + δSe. An inherent feature of the FIP-detectors is their specific response to the sum of simple CN- + Zn(CN)4 2- + Cd(CN)4 2-. For total WAD cyanide determination, ligand exchange (LE) and a newly developed electrochemical pre-treatment procedure for release of the bound cyanide were used. The LE pre-treatment ensures complete recovery only when the sample does not contain Hg(CN)4 2-. This limitation is overcome by implementing electrochemical pre-treatment which liberates completely the bound WAD cyanide through cathodic reduction of the complexed metal ions. A complete recovery of toxic WAD cyanide is achieved in the concentration range from 156 μg L-1 up to 13 mg L-1. A three-step protocol for individual and group WAD cyanide speciation is proposed for the first time. The speciation protocol comprises three successive measurements: (i) of non-treated, (ii) LE-exchange pre-treated; (iii) electrochemically pre-treated sample. In the presence of all WAD complexes this procedure provides complete recovery of the total bound cyanide along with its quantitative differentiation into the following groups: (1) Hg(CN)4 2-; (2) CN- + Cd(CN)4 2- + Zn(CN)4 2-; (3) Cu(CN)4 3- + Ni(CN)4 2- + Ag(CN)2 -. The presence of a 100-fold excess in total of the following ions: CO3 2-, SCN-, NH4 +, SO4 2- and Cl- does not interferes. Thus the proposed approach offers a step ahead to meeting the ever increasing demand for cyanide-species-specific methods. The equipment simplicity makes the procedure a good candidate for implementing in portable devices for in-field cyanide monitoring. © 2008 Elsevier B.V. All rights reserved. | |
| dc.identifier.doi | 10.1016/j.talanta.2008.04.047 | |
| dc.identifier.issn | 0039-9140 | |
| dc.identifier.scopus | SCOPUS_ID:47549095021 | en |
| dc.identifier.uri | https://rlib.uctm.edu/handle/123456789/145 | |
| dc.language.iso | en | |
| dc.source.uri | https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=47549095021&origin=inward | |
| dc.title | A new generation of cyanide ion-selective membranes for flow injection application. Part III. A simple approach to the determination of toxic metal-cyanide complexes without preliminary separation | |
| dc.type | Article | |
| oaire.citation.issue | 4 | |
| oaire.citation.volume | 76 |