DETERMINATION OF MAGNESIUM AND CALCIUM IN 30-PERCENT SODIUM-CHLORIDE BY ION CHROMATOGRAPHY WITH ONLINE MATRIX ELIMINATION

Ion chromatography with on-line matrix elimination reliably determines low microgram-per-litre amounts of magnesium and calcium in brine (30 % NaCl). Magnesium and calcium from 100 mu l of brine were concentrate d on a metal-chelating resin containing iminodiacetate functional grou ps. After excess sodium was rinsed away, magnesium and calcium were el uted from the metal-chelating column, separated on a cation-exchange c olumn, and detected by suppressed conductivity. This method was reprod ucible at 5 mu g/l magnesium and calcium in brine. (C) 1998 Elsevier S cience B.V. Ail rights reserved.