Abstract: A method and device employing the method that identifies a solution based on characteristic electrochemical signal. Many solutions are electroactive, thus producing an electric signal following excitation with an applied potential. An electrochemical sensor can detect these electric signals if it is placed in contact with the fluid. Moreover, a fluid of known composition will produce a characteristic electrochemical signal and this characteristic signal can be used to confirm the presence of that fluid. The use of characteristic electrochemical signal to identify a fluid can be conducted at all scales and in many different fields. A few examples include quality control in food production or pharmaceutical manufacturing or for detection of air bubbles in a fluid stream or for identification of medicament prior to administration via a body worn patch pump/pod.