Voltammetric Studies for Analytical Determination of Antibacterial Danofloxacin and Orbifloxacin

Abstract

The voltammetric behaviour of antibacterial danofloxacin (DANO) and orbifloxacin (ORBX) was studied in a
wide pH range from 5 to 12 using phase sensitive alternating current, cyclic voltammetry and differential pulse
cathodic adsorptive stripping voltammetric (DPCASV).The adsorption behaviour of both biological compounds
at the hanging mercury drop electrode was investigated in order to achieve an increase in sensitivity and a
possibility of the antibacterial DANO and ORBX determination by applying the adsorptive stripping
voltammetric method. Adsorptive preconcentration followed by differential pulse cathodic stripping showed one
wave at -1.27 V (DANO) and -1.37 V (ORBX) being the most sensitive for analytical determination of the
investigated compounds. The limits of detection of 2.93 x 10-9 M and 5.30 x 10-9 M, and quantitation 9.77 x 10-9
M and 1.77 x 10-8 M for DANO and ORBX, respectively, were achieved. The degree of interference from
coexisting metal ions and some organic compounds on the DPCASV signal for DANO and ORBX was
evaluated. The proposed method was successfully applied to the determination of the studied fluoroquinolones in
human urine and serum, obtained from healthy volunteers, without the necessity for sample pretreatment or timeconsuming extraction steps prior to the analyses.