Study of the influence of ordered media on the determination of lead by hydride generation inductively coupled plasma atomic emission spectrometry

• Published in: Analytica chimica acta 1993-11, Vol.283 (1), p.175-182
• Main Authors: Valdés-Hevia y Temprano, M.C., Aizpún Fernández, B., Fernández de la Campa, M.R., Sanz-Medel, A.
• Format: Article
• Language: English
• Subjects: Atomic emission spectrometry; Fruit juices; Hydride generation; Inductively coupled plasma spectrometry; Lead; Organised molecular assemblies
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/0003-2670(93)85220-E

Continuous-flow generation of plumbane from different media for sample introduction into an inductively coupled plasma (ICP) for the determination of lead by atomic emission spectrometry (AES) was investigated in detail. Different “organized molecular assemblies” (micelles and vesicles) were tried for plumbane generation using the ammonium peroxodisulphate-nitric acid system as oxidant and sodium tetrahydroborate as the reducing agent. Cetyltrimethylammonium bromide (CTAB) or, alternatively, didodecyltrimethylammonium bromide was found to accelerate plumbane generation in the oxidant mixture. The advantages of hydride generation using aqueous, micellar or vesicular media are discussed and critically compared in terms of sensitivity, selectivity and accuracy of the corresponding ICP-AES determination of low levels of lead. The method using ammonium peroxodisulphate-nitric acid-CTAB proved to be superior (detection limit 9 ng ml −1 and precision 1.4% at the 50 mg ml −1 level) to conventional hydride generation, and was applied to the determination of low levels of lead in soft drinks by ICP-AES. Validation of the results was carried out successfully by graphite furnace atomic absorption spectrometry.