Bromine and iodine determination in human saliva: Challenges in the development of an accurate method.

Autor: Novo DR; Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, 96160-000 Capão do Leão, RS, Brazil., Mello JE; Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, 96160-000 Capão do Leão, RS, Brazil., Rondan FS; Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, 96160-000 Capão do Leão, RS, Brazil., Henn AS; Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil., Mello PA; Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil., Mesko MF; Centro de Ciências Químicas, Farmacêuticas e de Alimentos, Universidade Federal de Pelotas, 96160-000 Capão do Leão, RS, Brazil. Electronic address: marcia.mesko@pq.cnpq.br.
Jazyk: angličtina
Zdroj: Talanta [Talanta] 2019 Jan 01; Vol. 191, pp. 415-421. Date of Electronic Publication: 2018 Aug 30.
DOI: 10.1016/j.talanta.2018.08.081
Abstrakt: In this work, an analytical method for bromine and iodine determination in human saliva was proposed. A simple protocol based on centrifugation and direct analysis of supernatant by inductively coupled plasma mass spectrometry (ICP-MS) was investigated. Although this method was feasible for bromine determination, iodine was partially present in the supernatant and an agreement about 54% with reference value was obtained. In addition, microwave-induced combustion (MIC) and microwave-assisted dissolution were also evaluated. Using MIC, 0.2 mL of saliva added on 300 mg of microcrystalline cellulose were efficiently digested. A diluted solution (50 mmol L -1 NH 4 OH) was used for analytes absorption, and a reflux step of 5 min was applied to ensure quantitative recoveries of Br and I. Accuracy was evaluated by analyte recovery experiments, and recoveries between 94% and 98% were obtained. Microwave-assisted dissolution was evaluated for 2.0 mL of saliva using also a diluted alkaline solution (25 mmol L -1 NH 4 OH) and a microwave irradiation program of 35 min (including the cooling step). Results for this method agreed with those obtained using MIC. Although MIC has also been appropriated for further determination of Br and I in saliva, microwave-assisted dissolution can be considered a simpler sample preparation method and it was effective for high amount of sample (up to 2.0 mL). Moreover, final solutions were compatible with ICP-MS analysis, allowing the quantification of Br and I in human saliva at ultra-trace concentrations (limits of quantification were 0.052 μg mL -1 for Br and 0.022 μg mL -1 for I).
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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