Abstract: Ion chromatograms are prepared with a chromatograph including a separation column and a conductivity measuring ion detection unit which are adapted to be selectively placed in communication with separate reservoirs for diluted and undiluted samples of a fluid to be analyzed. A control unit switches the reservoirs into communication with an eluent pump for displacing fluid samples through the detection unit in timed relationship such that the most concentrated ion is measured in the diluted sample prior to measurement by the detection unit of the last of the lesser concentrated ions. A pump having a controllable flow rate is connected to a mixing conduit through control valves which switch the flow to and from the reservoirs so that the reservoirs may be simultaneously filled with diluted and undiluted samples of fluid. The diluted sample may be prepared by mixing the undiluted fluid with the eluent.

Abstract: Ion chromatograms are prepared with a chromatograph including a separation column and a conductivity measuring ion detection unit which are adapted to be selectively placed in communication with separate reservoirs for diluted and undiluted samples of a fluid to be analyzed. A control unit switches the reservoirs into communication with an eluent pump for displacing fluid samples through the detection unit in timed relationship such that the most concentrated ion is measured in the diluted sample prior to measurement by the detection unit of the last of the lesser concentrated ions. A pump having a controllable flow rate is connected to a mixing conduit through control valves which switch the flow to and from the reservoirs so that the reservoirs may be simultaneously filled with diluted and undiluted samples of fluid. The diluted sample may be prepared by mixing the undiluted fluid with the eluent.