The determination of oxalates in fresh plant material

Abstract

A method is described for determining total oxalates in plants, by extraction with hydrochloric acid, precipitation as calcium oxalate from the deproteinised extract and subsequent titration with potassium permanganate. Soluble oxalates are determined in a similar manner, in aqueous extract. The later stages of the determination are carried out on a semi-micro scale, so that a number of determinations can be made simultaneously. The method is designed for fresh green plants only, as oxalate is lost on drying the material.

Calcium oxalate accumulation and soil weathering in mats of the hypogeous fungus Hysterangium crassum

“…The oxalate content of mat rhizomorphs was assayed by titration with KMnO 4 (Baker, 1952). Oxalate was extracted by boiling 0.5 g of dry H. crassum in 1 M HC1; the remainder of Baker's procedure was not changed.…”

Effect of different concentrations of diluted seawater on yield and quality of lettuce

“…Plant N was determined using the Kjeldhal method, as described by AOAC (1990), and percentage N was converted to crude protein multiplying by 6.25. The total oxalate was analyzed according to Baker (1952), using a method of extraction with hydrochloric acid, precipitation as calcium oxalate from the deproteinized extract and titration with potassium permanganate.…”

Simultaneous determination of selected anti-nutritional components in Asiatic plants using ion chromatography

“…Modified titration method of determination of water-soluble oxalates was as previously described by Baker [7]. The grounded, dried samples (3.00 ± 0.01 g) of studied plant samples were extracted by 50 mL boiling distilled water and then stirred for 15 min on a shaker.…”

“…Oxalates can be determined by various analytical methods, such as: KMnO 4 titration [7], high-performance liquid chromatography (HPLC) with UV detection [8], HPLC with enzymatic detection [9], capillary electrophoresis [10], ion chromatography [11], chemiluminescence [12] and spectrophotometry NIR [13].…”