Preconcentration of Ions in Water

Ion chromatography is frequently used to determine anions and cations at very low concentration levels, often in the low pg L (ppb) range. In the electric power industry the water used in steam generators must be almost free of Na, CT and other ions to avoid stress corrosion cracking of turbines, pipes, etc. The ionic content of ultrapure water used in the electronics industry must be kept to extremely low levels. Semiconductor chip manufacturers require clean rooms with utility impurities of no more than 1 ppb for 0.35pm devices (3). 

The sample breakthrough volume from the concentrator column needs to be measured in order to know how large a sample may be used. The sample must be of low ionic strength ( 50 pS), otherwise the sample itself can act as an eluent for the sample ions. A good discussion of the use of concentrator columns in 1C is available [4]. 

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