Ammonium oxalate monohydrate can be used to study chelators, biological buffers and biochemicals and reagents. Ammonium oxalate monohydrate has been used in an analysis of the effective segregation coefficient keff of different impurities, which suggested that the dehydration energies of cations mainly determine the capability of capture of impurity species by the growing crystal.

Complexes with Cu, thus inhibits spinach chloroplast phenolase.