| Abstract: | Abstract Analytical interference in the colorimetric determinations of ammonium and nitrate was examined in various KCl extracts of several ion exchange resins. No analytical interference was found in the colorimetric NO3 ‐‐N determination in any extract of any resin. However, a mixed‐bed (cation + anion) exchange resin extract substantially affected the colorimetric determination of NH4 ‐ ‐N. Recovery of adsorbed ammonium and nitrate from ion exchange resins was also studied as a function of KCl extractant strength and number of extractions. The recovery of adsorbed NO3 ‐‐N in the first extraction increased with increasing KCl concentration, with a 2 M solution recovering about 80%. However, a 1 M KCl solution gave the greatest recovery of ammonium‐N, recovering about 75–80% of the adsorbed ammonium. The second extraction with the same concentration of KCl solution was greater with the 0.5 and 2.0 M than with the 1 M solution so that total NH4 +‐N recovery after two extractions was about the same for all three KCl concentrations. The recovery of resin‐adsorbed NH4 +‐N and NO3 ‐‐N appeared independent of their concentrations on the resins. |
