FIA and Voltammetric Detection-A Happy Marriage

Two procedures involving amperometric detection and FIA have been described for the determination of the antioxidants tert-butylhydroxyanisole (BHA) and tert-butylhydroxytoluene (BHT) in corn oil samples [47]. During oxidation of both antioxidants, a glassy carbon electrode was possible to obtain good results in the presence of a solution of perchloric acid in 5% methanol (v/v). RSD percentage values were 2.2% (BHA) and 3.6% (BHT) for the repeatability study. 

A simple and quick method in FIA using a glassy carbon disk electrode modified with a molybdenum oxide film has been proposed for the quantification of iodate in commercial salt samples [48]. In this study, the film actuated as a catalytic agent in the reduction of iodate and a linear response was observed (from 1.0 x 10 to 1.0 x 10 mol r ). Other amperometric method coupled to FIA exploring the electrochemical reduction of iodate was also described [49]. Here, the authors used a more favorable working potential (+0.2 V vs. Ag/AgCl) in the presence of a solution of 1.0% w/v NaCl, 0.02% w/v KI, and 0.1 mol 1 HCl as carrier. 

In 2001, Buratti et al. [50] described an electrochemical method to evaluate the antioxidant power of lipophilic food extracts. The method was based on the association between FIA and amperometric detection and a working potential of +0.50 V (vs. Ag/AgCl) was used in the experiments. When applied to pure compounds, it was possible to observe that lycopene presented the greatest antioxidant power of all the lipophilic compounds (lycopene, )5-carotene, zeaxanthin, a-carotene, )5-cryptoxanthin, lutein, a-tocopherol, capsaicin, chlorophyll, astaxanthin, and canthaxanthin) used in this smdy. This result was 

The determination of nitrite in mineral water and in cured meat samples was performed using a glassy carbon electrode modified with a film of tetraruthenated cobalt porphyrin [51], associated with an FIA configuration. With this modified electrode, the anodic process was anticipated (working potential maintained at -1-0.75 V rather than -1-1.0 V) and a 15-fold current enhancement was verified with respect to results observed with the unmodified working electrode. By incorporating a copper-cadmium column before the amperometric detector and in the FIA manifold, it was possible to succeed the quantification of nitrate in the same samples. 

Masawat and Slater have presented the FIA method for determination of tetracyclines (tetracycline, chlortetracycline, and oxytetracycline) in chicken and shrimp meats and pharmaceutical samples [52]. The electrochemical oxidation of analytes was performed using a gold screen-printed electrode and good detection limits were achieved, 0.96,0.58, and 0.35)imoll for tetracycline, chlortetracycline, and oxytetracycUne, respectively. Moreover, some advantages of the screen-printed electrodes were highlighted such as potential for miniaturization, reliability, portability, low cost, simplicity of construction, and operation. 

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