On-line analysis of NH3, CO2, and SO2 diffusion through microporous teflon

Dynamic responses of self-made potentiometric NH3, CO2, and SO2 sensitive g as sensors are followed in the 10(-5)-5 x 10(-3)M concentration range. By l east squares fitting of potential versus time curves, Dk product values at the diffusion of NH3, CO2, and SO2 through microporous Teflon are calculate d. The obtained results are fairly reflected by the behavior of the sensor. Measurements of potential versus time in mixed solutions of CO2 and SO2 wi th the CO2 sensitive sensor indicate the presence of the interferent. (C) 1 999 John Wiley & Sons, Inc.