Noteworthy Method for Direct Determination of SbIII and Total Inorganic Antimony in Natural Waters

• Autor(a) principal: Neri,Thaís S.
• Data de Publicação: 2015
• Outros Autores: Carvalho,Dayene C., Alves,Vanessa N., Coelho,Nívia M. M.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532015000500985
• topic: antimony speciation; selective generation; HG AAS; water analysis

A procedure was developed for the direct determination of SbIII and total inorganic Sb in water samples by hydride generation atomic absorption spectrometry (HG AAS), without pre-reduction of SbV. The NaBH4 concentration was maintained at 0.4% (m/v) to perform the selective generation of stibine from SbIII and online stibine generation was carried out with 5.0% (m/v) NaBH4 to obtain the total antimony concentration. SbV was calculated as the difference between the values obtained for total Sb and SbIII. In both cases, the procedure did not appear to be adversely affected by potential interferents such as SbV, AsIII, AsV, CaII, NaI, chloride and phosphate at a concentration of 0.5 mg L-1. For the proposed procedure, the detection limits were 0.2 µg L-1 for SbIII and 0.3 µg L-1 for total Sb, while the relative standard deviations were 0.1% for 10.0 µg L-1 SbIII and 0.4% for 10.0 µg L-1 total Sb. A sampling rate of approximately 30 determinations perhour was achieved, requiring 300 mL of NaBH4, and the amount of waste generated was in order of 960 mL, indicating that this analytical procedure can be considered as green. The method was shown to be satisfactory for the determination of trace levels of antimony in water samples. The result obtained for the assaying of certified drinking water samples was 9.7 ± 0.1 µg L-1 (certified value 10.0 ± 0.5 µg L-1).