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Determination of iodide by low power surfatron microwave induced plasma after iodine continuous generation

1992; Elsevier BV; Volume: 47; Issue: 1 Linguagem: Inglês

10.1016/0584-8547(92)80008-5

1873-3565

Macarena Ortega, José Cotrino, M. Sáez, A. Garcı́a, José Enrique Sánchez Uría, Alfredo Sanz Medel,

Mass Spectrometry Techniques and Applications

This paper describes an improvement of the detection capability of the surfatron-microwave induced plasma (MIP) for iodide determination based on the chemical generation of iodine. This element is continuously generated by on-line mixing of iodide-sulfuric acid and hydrogen peroxide solutions. The iodine vapour is separated from the aqueous phase by a gas-liquid separator and is desiccated by passing it through concentrated H2SO4 before feeding it into the plasma. The system was optimized for the continuous generation of iodine and for its final determination in the MIP. The detection limit attained was 20 μg l−1 and the precision was ± 0.75% (at the 200 μg l−1 level). An interference study showed that the proposed determination is very selective in the absence of oxidizing/reducing agents. The proposed procedure has been tested for iodide determination in real samples of table salt with very good agreement between the experimental results and the certified values.