超高效液相色谱测定铝胁迫下水培毛竹根系分泌物中有机酸

以毛竹Phyllostachys pubescens种子作为实验材料，建立毛竹根系分泌物中有机酸的提取和测定方法，并测定铝胁迫下毛竹根系分泌物中有机酸。以毛竹水培法收集根系分泌物，分别以0，100，500，1 000，2 000 μmol·L^－1等5种不同浓度氯化铝溶液作为培养液进行培养，旋转蒸发浓缩、定容；使用ACQUITY ^TM Ultra Performance LC超高效液相色谱系统，以体积分数为3%的甲醇-磷酸二氢钾（0.01 mol·L^-1）（pH 2.6）溶液作流动相, 经HSS T3 C18柱分离，考察检测波长、色谱柱、流动相的 pH值及分离温度等因素对4种有机酸分离效果的影响。结果表明：样品制备简便，分离效果好，方法的线性范围及精密度、准确度和回收率都能满足毛竹根系分泌物中痕量有机酸定性和定量分析的要求。根据分析物的保留时间以及光谱图对样品色谱峰定性，水培毛竹根系分泌物中可以检出的有机酸为草酸和苹果酸；铝离子的存在对毛竹根系有机酸的分泌有促进作用，500 μmol·L^－1氯化铝溶液对有机酸分泌的促进作用最强。图2表2参14

Organic acid exudates from roots of Phyllostachys pubescens with aluminum stress

To develop a simple method to determine the organic acids exuded from roots of Phyllostachys pubescens,root exudates were obtained using a water culture method with treatments of 0,100,500,1 000,and 2 000 μmol·L-1 AlCl3 as the culture solution and analyzed through ultra performance liquid chromatography（UPLC） with ultraviolet（UV） detection.The exudate was concentrated in a rotary evaporator,and separation was performed on an ACQUITY ■ UPLC high-strength silica（HSS） T3 C18 column with 3% CH3OH-KH2PO4（0.01 mol·L-1）（pH 2.6）（V/V） as the mobile phase of an ACQUITY TM UPLC system.Analysis included the effect on separation of 4 organic acids（oxalic acid,malic acid,citric acid and succinic acid）using UV detection wavelength,chromatographic column,and the pH of the mobile phase.Results showed favorable recovery（95%-105%）,satisfactory precision（RSD2%）,and a good linear relationship（0.022-1.100 μg for the 4 organic acids）.According to the retention time and the spectrum of the analytes,the organic acids exuded were an oxalic acid and malic acid.The Al3＋ ions interacted with organic acid exudates with the strongest interaction when the concentration of AlCl3 was 500 μmol·L-1.