In this study a novel approach for simultaneous determination of cholesterol and its precursor 7-dehydrocholesterol by differential pulse voltammetry on boron doped diamond electrode was developed. They are oxidizable in mixed media of acetonitrile and strong acid exhibiting voltammetric peaks at potentials of ca +0.8 V and +1.1 V (7-dehydrocholesterol) and +1.45 V (cholesterol) (vs.
Ag/0.01 mol.l(-1) AgNO3/1 mol.l(-1) NaClO4). Detection limits in micromolar concentration range were obtained for both compounds.
DP voltammetry was applied on their determination in milk cream after liquid-liquid extraction standard addition method.