Determination of Low Molecular Weight Organic Acids in Soils and Cabbages by Gas Chromatography

The low molecular weight organic acids (LMWOAs) in rhizosphere soil, bulk soil, root and leave of cabbages were extracted and derived by the mixture of methanol and sulfuric acid (10∶7). Seven organic acids (oxalic, malonic, fumaric, succinic, maleic, L-malic and citric acid) were identified and quantified by GC instrument equipped with FID. The recovery were ranged from 81.93% to 95.58% for soils and from 84.78% to 106.99% for roots. The detection limit was ranged from 0.72 mg/kg to 4.14 mg/kg. The method was suitable for the reliable and accurate determination of low molecular weight organic acids in soils and cabbages.