An apparatus and process of controlling ink quality are provided. The process includes providing an imprinted polymer microbalance in an inkjet printer, whereby the microbalance presents an equilibrium setpoint vibratory characteristic when in contact with a setpoint ink containing at least one target compound compatible with the imprinted polymers; placing the microbalance in contact with a supply ink printer; measuring a vibratory characteristic of the microbalance; and issuing a warning when the vibratory characteristic is different from the setpoint characteristic.