Thin self-assembled monolayer for voltammetrically monitoring nicotinic acid in food

A novel and sensitive method for the determination of nicotinic acid was proposed and based on voltammetric behavior of nicotinic acid on a self-assembled monolayer of mercaptoacetic acid coated gold electrode. The adsorption-controlled anodic peak current for the oxidation of nicotinic acid on mercaptoacetic acid covered gold electrode was affected by the type and pH value of supporting electrolyte and by accumulation potential as well as by accumulation time, and enhanced linearly with the concentration of nicotinic acid in the range of 0.8 mM–0.45 μM with a detection limit of 0.14 μM. The proposed method was utilized successfully for the monitoring of nicotinic acid in food. The possible interaction of nicotinic acid with mercaptoacetic acid, which is responsible for the enhanced response of nicotinic acid on modified electrode, was also suggested.