An electrode pH meter (Orion 720A, Orion Pacific, Frankston, Australia) was then used to measure the pH. Fresh pH 7.0 and 4.0 standard buffer solutions (Ajax Finechem, Sydney, Australia) were used to calibrate the pH meter.
An electrode pHmeter (Orion 720A, Orion Pacific, Frankston, Australia) was thenused to measure the pH. Fresh pH 7.0 and 4.0 standard buffer solutions(Ajax Finechem, Sydney, Australia) were used to calibrate thepH meter.