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Mercury determination by FI-CV-AAS after the degradation of organomercurials with the aid of an ultrasonic field: The important role of the hypochlorite ion

2005; Elsevier BV; Volume: 68; Issue: 3 Linguagem: Inglês

10.1016/j.talanta.2005.06.004

1873-3573

José Luís Capelo, María G. Rivas, Leônidas Oliveira, C. Vilhena, Ana Carolina da Silva Santos, Tatiana Valada, M. Galésio, Paulo Roberto de Oliveira, Marco Gomes da Silva, Elvira M.S.M. Gaspar,

Water Treatment and Disinfection

Due to new findings, the methodology based on room-temperature ultrasonic irradiation (sonolysis) for conversion of organomercurials into inorganic mercury [J.L. Capelo, I. Lavilla, C. Bendicho, Anal. Chem. 72 (2000) 4979–4984.] is further investigated. Inorganic mercury is selectively determined by Flow Injection-Cold Vapour Atomic Absorption Spectrometry (FI-CV-AAS) using SnCl2/HCl. Complete oxidation of methyl-mercury can be accomplished within 90 s whilst phenyl and diphenyl-mercury can be degraded within 10 s using a 50% sonication amplitude (100 W nominal power) provided by a probe ultrasonic device (20.5 kHz frequency) and a 1 mol L−1 HCl liquid medium with the presence of hypoclorite ion. The importance of hypochlorite in reduction of organomercurials by stannous chloride is highlighted. Oxidation kinetics indicated a pseudo first-order reaction for methyl-mercury, phenyl-mercury, and dipheny-mercury.