地表水中浮游植物叶绿素a提取方法的改进研究

Improvement of Extraction Method of Chlorophyll a in Phytoplankton in Surface Water

[目的]优化地表水中浮游植物叶绿素a的提取方法。[方法]以新配制的90%丙酮为提取液,在低温与室温下反复地冻融浮游植物以破碎细胞,多次震摇后冷藏静置以提取叶绿素a,并与规范法进行对比。[结果]改进法提取的叶绿素a含量较规范法明显提高,且重复测定的精密度较高。两种方法的测定结果存在明显差异,但在含量测定的趋势上具有较强的一致性。改进法可以满足750 nm处吸光值低于0.005的要求,而规范法不能。镜检表明,改进法的植物细胞破碎情况比规范法更佳。[结论]改进法提取浮游植物叶绿素a含量明显高于规范法且重复性较好,具有人为误差小、稳定性好、提取率高、结果准确、操作简便安全等特点。

[Objective] The study aimed to optimize the extraction method of chlorophyll a in phytoplankton in surface water. [Method] With new prepared 90% acetone as extraction solution, the phytoplankton was frozen and melted repeatedly to crack the cells at low and room temperatures and then was frozen to exwact the chlorophyll - a after repeatedly shaking. This method was contrasted with normative method. [ Result] Compared with normative method, the chlorophyll a content exwacted by the inlproved method was increased obviously and the precision of repeated determination was higher. There was signifi- cant difference between the determination results of the two rtlethods, but the stronger consistency in the trend of content determination. The improved method could meet absorption value, which was lower than 0.005 at 750 nm, however, the normative method couldn＇t do it. The microscopic examination indicated that the cracking condition of plant cells by improved method was better that that by normative method. [ Conclusion] The Chlorophyll a content in phytoplankton extracted by the inrproved method was significantly higher than that by normative methcd and had better repeatability. It possessed characters such as little artificial error, good stability, high extraction rate, accurate result, simple and safe operation.