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bioRxiv · 10.64898/2026.05.05.722854

Ammonium retention by Amberlite IRC-748 resin: useful for concentration assessments

Zhang, H.·Neidhardt, H.·Seitz, S.·Scholten, T.·Oelmann, Y.
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Abstract

Chelating ion exchange resins are widely used to eliminate metal interferences in the analysis of ammonium (NH4+) in soil extraction solutions. However, their potential to co-adsorb NH4+ remains underexplored. Here, synthetic metal ion solutions containing 6-30 mg L-1 NH4+ and the metal cations Ca2+, Mg2+, Cu2+, Mn2+, and Zn2+ were treated with Amberlite IRC-748 resin. The resin efficiently removed Ca2+ (-42.2%), Mg2+ (-21.1%), Cu2+ (-99.9%), Mn2+ (-56.9%), and Zn2+ (-93.6%). However, NH4+ losses of 2.2-5.6% were observed, indicating concentration-dependent co-adsorption. While these losses may be acceptable for concentration measurements via routine assays such as photometric analysis, they may still affect the accuracy of high-precision N analyses that rely on quantitative NH4+ recovery. This highlights a methodological caveat for resin-treated samples, especially in low-NH4+ environments. We therefore recommend including recovery assessments and correction factors when using chelating resins to improve accuracy in NH4+ quantification.

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Zhang, H., Neidhardt, H., Seitz, S., Scholten, T., Oelmann, Y.. 2026-05-07. Ammonium retention by Amberlite IRC-748 resin: useful for concentration assessments. https://doi.org/10.64898/2026.05.05.722854

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