ION-CHROMATOGRAPHIC DETERMINATION OF TRACE ANIONS AND CATIONS IN HIGH-PURITY WATER

An ion chromatographic measuring system for the off-line and on-line d etermination of some trace anions and cations in high-purity water is presented. The ng/L level of anions and cations in 20-130 mL high-puri ty water can be analyzed after preconcentration on ion exchange column s. Tile concentrated solutes are eluted by eluents from the trap colum n and separated using a Dionex analytical column. The quantification o f each ion is achieved using the suppressor technique and conductivity detector. The influence of Various parameters on the results is discu ssed. The detection limits of cations and anions are between 10 and 30 ng/L for chloride, bromide, nitrate, phosphate, sulphate, sodium, amm onium, potassium, magnesium and calcium ions.