Development of a micro-heater for flow analysis systems: spectrophotometric determination of manganese in plant digest
| Autor: | Maria Cristina Tomazzini, Boaventura F. Reis, Marisa Smiderle |
|---|---|
| Jazyk: | portugalština |
| Rok vydání: | 2004 |
| Předmět: |
Detection limit
Argon Chromatography Permanganate Analytical chemistry chemistry.chemical_element Periodate General Chemistry Manganese lcsh:Chemistry chemistry.chemical_compound lcsh:QD1-999 chemistry manganese determination Reagent micro-heater device Optical emission spectrometry multicommutated flow system Phosphoric acid |
| Zdroj: | Química Nova, Volume: 27, Issue: 1, Pages: 50-54, Published: FEB 2004 Química Nova v.27 n.1 2004 Química Nova Sociedade Brasileira de Química (SBQ) instacron:SBQ Química Nova, Vol 27, Iss 1, Pp 50-54 (2004) |
| Popis: | In this work a micro-heater device to be used as an integral part of the flow analysis manifold is described. The usefulness of the device was demonstrated using it in the development of a multicommutated flow analysis procedure for the spectrophotometric determination of manganese in plant digest. The method was based on the manganese oxidation by periodate in phosphoric acid medium to form the permanganate anion. The reaction development is dependent on the temperature and it was observed that at 25 °C a time interval of ca. 15 min was necessary for the reaction to attain equilibrium. Setting the temperature to 70 ºC, this time interval could be decreased to ca. 30 s. This condition was easily attained employing the proposed micro-heater device coupled to the manifold. The procedure was applied to manganese determination in soybean digests and results compared with those obtained by inductively coupled argon plasma optical emission spectrometry (ICP-OES). No significant difference at 90% confidence level was observed. A linear response for sample concentrations ranging from 5.0 to 30.00 mg L-1 Mn2+; a relative standard deviation of 1.3% (n = 6) for a typical sample containing 6.3 mg L-1 Mn2+; a sampling rate of 22 determinations per hour; a low reagent consumption, of 12.0 mg NaIO4 per determination; and a detection limit of 1.2 mg L-1 were achieved. |
| Databáze: | OpenAIRE |
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