SIMULTANEOUS DETERMINATION OF THE 3 MAIN INORGANIC FORMS OF NITROGEN BY ION CHROMATOGRAPHY

An ion chromatographic method for the determination of nitrite, nitrat e and ammonium simultaneously is described. An appropriate eluent-colu mn-detector combination for separating and detecting these ions is dis cussed. On a bifunctional ion-exchange column, nitrite and nitrate ani ons were separated by anion exchange and ammonium cation by cation exc hange. Nitrite and nitrate were detected by UV spectrometry and ammoni um using a chemically suppressed conductivity detector. The detection limits for the three ions were all below 0.02 ppm (w/w) and the relati ve standard deviations for the three ions were all less than 0.5%. Sev eral samples such as water, soil and acid rain were analysed with this method and the recoveries of the three ions were all within 100 +/- 5 %. The results agreed well with those obtained by a standard method.