This article reports for the firsttime the anodic stripping voltammetric (ASV) detection of Zn at a gold disk
macroelectrode for the analysis of fuel bioethanol. The accurate determination of Zn at gold
macroelectrodes was only possible with the aid of batch injection analysis (BIA) associated with ASV;
this statement was proved by comparison with a conventional three-electrode system. The BIA system
consisted of injections of bioethanol sample plugs (up to 1 mL) at 28.3mL s
1 directly onto a working
(gold disc) electrode immersed in 0.04 mol L1 Britton-Robinson buffer (pH 7) solution through an
electronic micropipette and the Zn deposition occurs simultaneously. The highest analytical response for
Zn was obtained for a deposition time of 90 s, which indicated that Zn deposition also occurred from
diffusion after the injection ended. The proposed method presented a low detection limit (5mg L1
), a
linear range between 25 and 250mg L1
, and adequate recovery values (88–104%) for spiked samples, but
no sample treatment was required. Such remarkable analytical features associated with the portability
characteristics of BIA demonstrated the promising application of the proposed method for routine and
on-site determination of metals in fuel bioethanol.