Electrocatalytic adsorptive voltammetry for fludarabine determination in urine

Fludarabine (F-Ara-A, 9-(beta)-D-arabinofuranosyl-2-fluoroadenine) is an arabinosyl nucleoside with potent cytotoxic activity against chronic lymphocytic leukemia. Herein, its electrochemical behavior is investigated on pyrolytic graphite electrodes (PGEs); and a novel catalytic adsorptive differential-pulse-voltammetric method for its determination is developed based on the strong electrocatalytic effect on nicotinamide adenine dinucleotide (NADH) oxidation exhibited by the oxidation products of F-Ara-A. This approach was applied to human urine samples, which required a previous solid-phase extraction. The F-Ara-A recovery was of 89.7%. The method proposed is fast, simple and permits detection of F-Ara-A concentrations up to 72 h after infusion.