An electrochemical polymerization based salt content analyzer configured to determine salt composition in a direct, fast, and serial manner. The salt content analyzer includes three electrodes: a working electrode, a counter electrode and a reference electrode. In operation, the current passing through the electrodes as a sweeping voltage is applied may be analyzed to determine the salt content of the analyte. When a voltage is applied, an electro-polymerizable monomer forms a thin film on the working electrode. The working electrode includes an access control mechanism to only expose a fraction of the working length of the working electrode to the outside environment at any given time. The access control mechanism is advanced between tests to expose a fresh portion of the working electrode and conceal the portion with a thin film of electro-polymerized monomer. Thus, testing may be performed in a serial manner.