Abstract: A pressure column of the analyzer communicates with a concentrator made up of a plurality of series-connected evaporators. Arranged at the outlet of a first evaporator is an electroconductivity sensor whose output signal indicates ammonia concentration, and the first evaporator's throttle is provided with a passage aperture which is peferably 1.5 or 2 times less than the throttles of the other evaporators. Provided at the outlet of the last evaporator is another electroconductivity sensor whose output signal indicates the concentration of salts. Both sensors are optionally connected to a common recorder, thereby ensuring simultaneous recording of the concentration of both salts and ammonia.