Amperometric Determination of Aminobiphenyls Using HPLC‐ED with Boron‐Doped Diamond Electrode

Amino derivatives of biphenyl have been proven to be genotoxic and/or carcinogenic, thus they are widely monitored in the environment as well as in biological liquids. This study was devoted to HPLC determination of 2‐aminobiphenyl, 3‐aminobiphenyl, and 4‐aminobiphenyl in model drinking and river water samples using amperometric detection in a thin layer cell with boron doped diamond thin film electrode. Satisfactory separation of studied analytes was achieved at a ChiraDex column (Merck, Germany) with chemically bonded β‐cyclodextrin in a mobile phase aqueous buffer/acetonitrile/methanol (40/30/30, v/v/v) with total separation time of six minutes. The highest detector response with satisfactory repeatability (relative standard deviation <2.9% for all aminobiphenyls) was obtained using 0.01 mol L−1 acetate buffer at pH 5.0 as an aqueous component of the mobile phase. For direct determination of aminobiphenyls in drinking and river water model samples limits of quantitation ca. 4×10−7 mol L−1 were achieved. Applying off‐line solid phase extraction using Lichrolut EN (Merck, Germany) cartridges and elution by diethyl ether, limits of quantitation were lowered down to the 10−9 mol L−1 concentration range.