A stationary probe having a probe holder and a probe with a probe tip. The stationary probe may be part of a stationary probe rotating disk electrode wherein the stationary probe has a passage therethrough for rotatably receiving a rotating disk electrode comprising a rotating shaft, rotatable about a longitudinal axis, and having an electrode portion extending therefrom configured to receive an electrode. The stationary probe rotating disk electrode may be part of an analytical system wherein the probe tip includes a capillary entrance spaced apart from the electrode and connected to an analyte flow path.