Simple method for determination of oxalic acid in forages using high-performance liquid chromatography

We established a simple method for determination of oxalate in forage grasses using high-performance liquid chromatography (HPLC) with an anion analysis column (Shodex 1C SI-90 4E) and sodium hydrogen carbonate (NaHCO3) as eluent. Oxalate was determined after extraction with water or 1 mol HCl (soluble form or total, respectively). Insoluble oxalate was estimated as the difference between total oxalates and soluble form. Recovery of oxalate after HPLC was above 97%. Oxalates in forages could be successfully determined by this method. The method was simple, fast and inexpensive.