Por favor, use este identificador para citar o enlazar este ítem:
http://cimav.repositorioinstitucional.mx/jspui/handle/1004/1638| Analytical Methodologies for Arsenic Determination Exploiting Flow Injection-Based approaches | |
| LUZ OLIVIA LEAL QUEZADA | |
| Acceso Abierto | |
| Sin Derechos Reservados | |
| Arsenic | |
| Threc flow injection based approaches have been developed for determination, pre-concentration and speciation analysis of arsenic by hydride generation atomic fluorescence spectrometry (HGAFS). The arsenic determination was carried out using a multisyringe burette coupled with a solenoid valve. providing precise known volumes of sample and reagents. which are dispensed into a gas—liquid separation cell. An argon flow delivers the arsine into the flame of an atomic fluorescence spectrometer. A hydrogen flow has been used to support the flame. Nitrogen has been employed as a drier gas. The second flow injection approach was constructed for arsenic pre-concentration on a solid-phase, using a column packed with an anion-exchange resin and coupled to the previous system. The speciation analysis of inorganic arsenic was carried out using a pre-reducing solution. Total inorganic arsenic was determinad after on-line pre-reduction of As(V) to As(II I) using potassium iodide. The concentration of As(V) was calculated by thc di fference of the total inorganic arsenic and As(llI). Several variables such as sample and reagents volumes, flow ratos and reagent concentrations were investigated in detail. The proposed techniques have been validated by means of reference solid and water materials with good agreement with the certificd valucs. The obtaincd results show that the proposed methodologies otfcr some advantages such as compactness, high sampling frequency. optimum sensitivity, high selectivity and decreasns of reagents and sample consumption, which Ieads to a lower waste generation. It confirms the statement that the use multisyringe systems considerably extends the possibilitics of flow analysis. | |
| 2009 | |
| Memoria de congreso | |
| Inglés | |
| OTRAS | |
| Versión revisada | |
| submittedVersion - Versión revisada | |
| Aparece en las colecciones: | Artículos de Congresos |
Cargar archivos:
| Fichero | Tamaño | Formato | |
|---|---|---|---|
| Extenso_Leal et al.pdf | 579.09 kB | Adobe PDF | Visualizar/Abrir |