The voltammetric behaviour of Enrofloxacin (I), Sparfloxacin (II) and Flero
xacin (III) was studied using direct current (DCt), differential pulse (DPP
) and alternating current (AC(t)). All the drugs manifest cathodic waves in
Britton-Robinson buffer over the pH range of 4.0-11.98. The waves were cha
racterized as being irreversible, diffusion-controlled with limited adsorpt
ion properties. The diffusion current-concentration relationships were foun
d to be rectilinear over the ranges 4 x 10(-5) - 5 x 10(-4) M, 1 x 10(-5) -
2 x 10(-4) M, 1 x 10(-5) - 4 x 10(-4) M using DCt mode for I, II and III,
respectively and 1 x 10(-6)-4 x 10(-5) M. 1 x 10(-6)-1 x 10(-4) M. and 2 x
10(-6)-8 x 10(-5) M, using DPP mode For I. II and III respectively, with mi
nimum detectability (S/N = 3) of 1 x 10(-7); M for I, II and 2 x 10(-7) M f
or III. The proposed method was successfully applied to the determination o
f the studied compounds either per se or in formulations and biological flu
ids. The results obtained were concordant to those given using reference me
thods. (C) 2000 Elsevier Science B.V. All rights reserved.