SPECIATION OF CHROMIUM BY COUPLED-COLUMN HPLC-ICP-MS - THE EFFECTS OFINTERFERING IONS

ICP-MS is used as an element selective detector for chromium species i n aquatic samples using a coupled columm system consisting of a cation guard column and an anion column. The effects of large concentrations of disturbing ions, like NO3-, Cl-, CO32- and SO42-, are discussed an d the comparison with the use of different chromium isotopes for data acquisition is given. Quite low concentrations such as 100 mg/l of CO3 2-, 10 mg/l Cl- and even 5 mg/l SO42- can cause an overestimation of c hromium if not properly resolved