利用高能液相色谱测定根际分泌物中的有机酸: Ⅲ.干扰因子的影响

Methods for determining niene low molecular-weight oragnic acids in root exudates were developed by using reversed-phase high performance liquied chromatography with UV (ultraviolet) detection at 214 nm. The mobile phase was 18 mmol L^-1 kH2PO4 adjusted to pH 2.25 with phosporic acid nd the flow rate was 0.3 mL min^-1,The analytical column was a reversed-phase silica based C-18 column( shim-pack CLC-ODS).The root exudates were collected through submerging the whole root system into aerated deionized water for 2 hours ,The filtered exudate solutions were concentrated to dryness by rotary evaporation at 40℃,dissolved in 10 mL mobile phase.The chromatoraphic conditions of organic acid determination were analyzed.The results showed that there was a high selectivity and sensitivity in the organic acid determination by reversed-phase high performance liquid chromatography.Coefficients of variation for organic acied determination were lower than 10% except lactic acid .The recoveries were consistently between 80.1% to 108.3% .Detection limits were approximately 0.05 to 4.5 mg L^-1 for organic acids except succinic acid with the detection limit of 7.0 mg L^-1 .Phosphorus deficiency may contribute to the release of organic acids in soybean root exudates especially malic,lactic and citric acids.