Platinum electrodes in microcylindrical and tubular arrangements were compared as working electrodes for amperometric detection of 2‐aminobiphenyl, 4‐aminobiphenyl, 1‐aminonaphthalene, and 2‐aminonaphthalene in HPLC. Factors influencing separation efficiency are favourable for microcylindrical arrangement while tubular arrangement exhibits higher sensitivities and lower limits of detection. These are in the range of 0.0078–0.027 µmol L−1 for tubular, and 0.11–0.42 µmol L−1 for microcylindrical arrangement. Further, a new method with nanomolar detection limits was proposed for determination of tested compounds in urine using solid phase extraction for preliminary separation and preconcentration of the analytes.