Determination of ketorolac in human serum by square wave adsorptive stripping voltammetry

The adsorption behavior of ketorolac on a hanging mercury drop electrode (H MDE) was explored by square-wave and cyclic voltammetry. The square wave vo ltammetric response of ketorolac depends on the parameters of the square wa ve voltammetry excitation signal as well as on the pH of the medium and the accumulation time. The drug was accumulated at HMDE and a well-defined pea k was obtained at - 1.41 V versus. Ag/AgCl (saturated KCI) in acetate buffe r of pH 5.0. A square-wave adsorptive stripping voltammetric method for the quantitative determination of ketorolac was developed. The linear concentr ation range was 1 x 10(-10)-1 x 10(-8) when using 300 s accumulation at - 0 .8 V. The detection limit of ketorolac was 1.0 x 10(-11) M. The precision w as excellent with relative standard deviation of 3.85% at concentration of 5 x 10(-8) M after 60 s accumulation time. Applicability to serum samples w as illustrated. A detection limit of 14 ng per mi of serum was obtained. (C ) 2001 Elsevier Science B.V. All rights reserved.