Simultaneous determination of VMA, HVA, and creatinine using HPLC
In this report vanillylmandelic acid (VMA), homovanillic acid (HVA) and creatinine were measured simultaneously by reversed phase HPLC and pre-processing was remarkably improved by HPLC autosampling with a micro-plate. A UV detector was used for creatinine and a coulometric detector (ECD) for VMA and HVA.