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

A solution culture experiment was conducted to investigate the effects of collection time and interfering ions on separation and determination of low-molecular-weight organic acids in root exudates of soybean using the method for directly collecting root exudates.The suitable cooection time of root exudates and the interferiung ions affecting organic acid determination were determined.The method for removing the interfering ions was established and analyzed.The release amount of root exudates increased with the increase of collection time from 0 to 120min but decreased with increasing of collection time from 120to 240min.The maximum exuding amounts of organic acids were observed in root exudates at the collection time of 120min.There was a significant difference of organic acid components between the treatments of collection time of 120min and 240min,Citric acid was founnd only in the treatment of 120min collection time,NO3^- was the main interfering ion in organic acid determination and had the same retention time as oxalic acid.Anion exchange resin(SAX)properly treated by HPLC(high performance liquid chromatography)solvent could remove NO3^- anion in sample solution of root exudates,thus enhancing the recoveries of organic acids in root exudates.There was no significant effect of the chemicals added into sample solution such as H3PO4,SAX and KNO3 on the retention time of organic acids.