浮游植物叶绿素a的微波法研究及其与反复冻融法的比较

为缩短样品处理时间和提高测定准确度,本文设计和优化了微波处理辅助提取浮游植物叶绿素a的方法,并比较了反复冻融法和微波法对浮游植物叶绿素a的提取效率.结果表明:(1)微波法提取叶绿素a的最优处理条件为:高火(额定输出功率800 W)处理60 s左右.过滤水量为:贫营养型水体为1000 ml以上,中、富营养水体为100~500 ml.(2)反复冻融法在测定贫营养型水体时更稳定,而微波法对中、富营养水样提取率显著高于冻融法,可提高7%~12%,对具胶被及硅质外壳的藻类提取效率极显著高于冻融法,测定结果的相对偏差更小,且提取时间较冻融法缩短一半以上,适用于富营养化水体的应急监测.

Microwave-assisted method for extracting chlorophyll-a in phytoplankton and its comparison with freezing-thawing extraction method

In order to save time of sample processing and to improve the determining accuracy, a microwave-assisted extraction method was designed and optimized to extract chlorophyll-a in phytoplankton, and was compared to the freezing-thawing method for extraction efficiency of chlorophyll-a. The results showed that microwave-assisted extraction method was optimal in 60 s treatment with output power of 800 W, and the appropriate water volume for filtration was about 100-500 ml for samples collected in meso-eutrophic waterbodies and 1000 ml for those from oligotrophic waterbodies. The chlorophyll extraction rate of microwave-assisted extraction method was significantly higher than that of freezing-thawing method in meso-eutrophic waterbodies, which can increased by 7%-12%, while freezing-thawing method was more stable in measuring chlorophyll-a of oligotrophic waterbodies. For those algae with a glue shell or siliceous shell, microwave-assisted extraction method had a higher efficiency for chlorophyll-a extraction and a lower relative standard deviation than the freeze-thaw method. The microwave-assisted extraction method needs only one half operation time of the freezing-thawing extraction method, so that it is more suitable for emergency monitoring of eutrophic waterbodies, while the freezing-thawing extraction method is more suitable for monitoring oligotrophic waterbodies.