An improved flow-injection system for spectrophotometric determination of molybdenum and tungsten in tool steels
| Autor: | Silvia R.P. Meneses, Paula R. Fortes, Ana Paula G. Gervasio, Elias A.G. Zagatto, Carlos Eduardo Saraiva Miranda |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Ion exchange
medicine.diagnostic_test Alloy steel Inorganic chemistry Analytical chemistry chemistry.chemical_element engineering.material Tungsten Analytical Chemistry Catalysis chemistry.chemical_compound chemistry Molybdenum Spectrophotometry engineering medicine Iodide oxidation Hydrogen peroxide |
| Zdroj: | Talanta. 69:927-931 |
| ISSN: | 0039-9140 |
| DOI: | 10.1016/j.talanta.2005.11.042 |
| Popis: | A flow-injection procedure for simultaneous spectrophotometric determination of tungsten and molybdenum in steel alloys is proposed. The method exploits the catalytic effects of Mo(VI) and W(VI) on the rate of iodide oxidation by hydrogen peroxide under acidic conditions. A novel strategy for ion-exchange separation of the potential interfering species is proposed, and an AG50W-X8 cationic resin mini-column is used. The sample is injected twice, originating two sequential plugs, citrate being added to one of them in order to suppress the W(VI) catalytic activity thus providing the kinetic discrimination. The system handles 70 samples per hour and requires 1.6mg KI per determination. A linear response is verified up to 10mgl(-1) Mo (or W) in the injectate, and signal additivity is 98-103%. Results are precise (R.S.D.0.04) and in agreement with ICP-OES. Running a standard reference material (IPT-50) assessed also accuracy. |
| Databáze: | OpenAIRE |
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