Voltammetric analysis of biological fluids: quantification of species in urine accounting for non-linear concentration effects

Abstract

AbstractVoltammetric sensing of analytes in biological fluids is frequently accompanied by non-linear effects due to the analyte/matrix interactions. A theoretical approach is developed to describe such effects when standard addition methods are applied. Several asymptotic models are described considering equilibrium-like and kinetic-like interaction models and possible co-diffusion effects. Experimental data for non-linear features which appear in voltammetric sensing of serotonin and noradrenalin in urine are in satisfactory agreement with theoretical predictions.