高效液相色谱法测定设施番茄土壤低分子量有机酸的色谱条件研究

Study on Chromatographic Condition in Determination of Low Molecular Weight Organic Acids in Tomato-planted Soil under Greenhouse with HPLC

为探索利用高效液相色谱法测定设施番茄土壤低分子量有机酸的适宜色谱条件,以Na OH和Na Cl混合溶液为提取剂提取11种土壤低分子量有机酸,通过优化影响低分子量有机酸分离度的流动相浓度、p H、流速、有机改良剂的添加比例、检测波长等条件,确定了高效液相色谱法测定设施番茄土壤低分子量有机酸的最佳色谱条件为:以10 mmol L-1KH_2PO_4-CH_3OH(97∶3,p H 2.6)为流动相,流速为0.8 ml min^(-1),检测波长220 nm,柱温25℃,进样量为20μl。此方法对11种低分子量有机酸的检测限在20~825 ng ml^(-1)之间,回收率在85.57%~100.20%之间,相对标准偏差在0.17%~5.84%之间。实际土壤样品分析结果表明,该方法能够满足土壤低分子量有机酸的痕量检测要求。

The mixed solution of Na OH and Na Cl was used to extract eleven low molecular weight organic acids in soil, the resolution between different organic acids might be affected by the factors, such as concentration and p H of mobile phase, flow rate, application ratio of organic modifier and detected wavelength. These factors were optimized to establish an optimum condition for the determination of low molecular weight organic acids in tomato-planted soil under greenhouse with through high performance liquid chromatographic（HPLC）. The optimum chromatographic conditions were as the follow： the mobile phase was 10 mmol L-1KH2PO4-CH3OH（V∶V=97∶3, p H=2.6）, the flow rate was 0.8 ml min-1, the detect wavelength was 220 nm, the column temperature was 25 ℃ and the volume of sample was20 μl. The proposed method had been applied to determine the eleven low molecular weight organic acids in soil solution of greenhouse tomato, and found the detection limits ranged from 20 to 825 ng ml-1, the average recoveries ranged from 85.57% to 100.20%, and the relative standard deviation ranged from 0.17% to 5.84%. The results of soil solution indicated that the established method could be applied to analysis the low molecular weight organic acids in environment samples especially in soil solution with trace concentration.