Abstract: There is described an analyzing device having two separation units to separate molecular species to detect molecular species in wellbore fluids with both separation units operating under forced flow conditions to provide for an active separation of subterranean wellbore effluent into its components for subsequent analysis.

Abstract: There is described an analyzing device having two separation units to separate molecular species to detect molecular species in wellbore fluids with both separation units operating under forced flow conditions to provide for an active separation of subterranean wellbore effluent into its components for subsequent analysis.

Abstract: A microfabricated potentiometric sensor and a method of measuring the activity of analyte ions in a sample solution, the sensor comprising: a substrate chip; a flow channel defined by the substrate chip through which analyte ions of a sample solution are in use driven; at least one ion-selective electrode comprising a chamber defined by the substrate chip and including a port in communication with the flow channel, an ion-selective membrane disposed in the chamber, and a conductive element configured such as in use to be in electrical connection with the ion-selective membrane; a reference electrode configured such as in use to be in electrical connection with the flow channel; whereby, on driving analyte ions of a sample solution through the flow channel, an electromotive force is developed between the at least one ion-selective electrode and the reference electrode which is representative of the activity of the analyte ions.