Pedosphere 9(1): 45--52, 1999
ISSN 1002-0160/CN 32-1315/P
©1999 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Determination of organic acids in root exudates by high performance liquid chromatography: Ⅱ. Influence of several testing conditions |
| SHEN Jian-Bo, ZHANG Fu-Suo and MAO Da-Ru |
| Department of Plant Nutrition, China Agricultural University, Beijing 100094 (China) |
| ABSTRACT |
| Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed-phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 nm and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃~45 ℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH. |
| Key Words: chromatographic conditions, high performance liquid chromatography (HPLC), organic acids, root exudates |
| Citation: Shen, J. B., Zhang, F. S. and Mao, D. R. 1999. Determination of organic acids in root exudates by high performance liquid chromatography: Ⅱ. Influence of several testing conditions. Pedosphere. 9(1): 45-52. |
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