Development of an in-situ method of pH measurement with calibration for use under high hydrostatic pressures

Though pressure has been used in food processing for over 30 years, there is still no clear choice when determining the pH of a sample under high hydrostatic pressure. A cell design is proposed for use as a pH sensing device that functions under high pressure. The design mimics the glass pH electrode in that it uses a working and reference electrode to measure the potential of a solution. Calibration of the sensor under high pressure relied on the use of two baroresistant buffers at pH 4 and 7. The sensor did show a change in voltage with pH under pressure, but showed reduced sensitivity as pressure increased and low precision in measured values. A baroresistant buffer was developed at pH 7, but was not at pH 4. A second baroresistant calibration buffer and improvement in the sensors sensitivity are necessary before the design can be used in analytical experiments.