Determination of amino acids by capillary electrophoresis with differential resonant contactless conductivity detector

► The sensitivity of contactless conductivity detector in capillary electrophoresis is improved. ► The dependence of wall capacitance on solution conductivity and capillary dimension is reported. ► Capillary electrophoresis with end-to-end differential detection is reported. ► The responses of different contactless conductivity detectors are compared.