New potentiometric gas-gap sensor Original Research Article

A new gas-gap sensor for the determination of ammonia on the base of a pH-metric electrode is described. It has been established that the equality of the ionic strength and temperature of the sample and the electrode solution is no longer necessary. This allows to reduce the limit of detection for ammonia to 5×10−10 M, to vary the measurable ammonia concentration range from 1×10−9–1×10−5 M up to 1×10−7–1×10−3 M and to reduce the response time to several minutes.