Development of an electrochemical sensor and measuring the shelf life of tinplate cans.

• An sensor is designed to evaluate the shelf-life of tinplate cans. • Open circuit potential can be used as an indicator for corrosion resistance. • Potentiostatic step and EIS are fast methods for shelf-life assessment. • Shelf-life can be assessed by electrochemical equivalent circuit modeling. An electrochemical sensor is developed to evaluate the shelf life of lacquered tinplate cans by using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiostatic step techniques. The voltage and current detection precision of measurement system are 0.25 mV and 500 pA. The evolution of OCP, coating resistance, charge transfer resistance, and current response after potentiostatic step can be used as indicators for shelf life evaluation. Through establishing the electrochemical equivalent circuits (EECs), the change of the corrosion resistance over time is formulated and its correlation with shelf life is elucidated. The results show that electrochemical methods are successfully applied in fast shelf-life assessment of metal packaging cans. [ABSTRACT FROM AUTHOR]