Comparison between a differential amperometric detector in the reductive mode and a u.v. detector in high-performance liquid chromatography with vitamin K3 as test compound

Abstract The amperometric detector is superior to the u.v. detector in terms of the limit of detection (less than 0.5 ng) and true linearity of response when vitamin K3 (menadione) is used as the test compound with a reversed-phase column. However, the high uncompensated resistance between the reference and working electrodes caused by the low conductivity of the mobile phase, restricts the upper limit of the linear range of the differential amperometric detector to about 200 ng of menadione.