Study On The Method Of Extraction And Determination Of Chlorophyll-a In Freshwater Algae

Due to the impact of many of our lakes and reservoirs water eutrophication for water to give raw water containing different levels of algae, algae algal toxins are released, threatening the safety of water quality. Chlorophyll is the main photosynthetic pigment of algae, often, chlorophyll a, the content of algae dry weight is about 1% to 2%, which is an important indicator of algal biomass. Currently used in the field of chlorophyll a determination to use more spectrophotometry and fluorescence spectrometry, fluorescence spectrometry for sensitive than spectrophotometry, and now use more fluorescence.This article is based on previous research, the main reservoir for the Queshan algae types, laboratory-based research, from the extraction methods, extraction agents, monitoring methods, studies of freshwater algae and the optimum extraction of chlorophyll a fluorescence measurement program. In this thesis, results are as follows:1. The green algae chlorella in the study object, from the extraction ability, fidelity, broad applicability, accuracy, simplicity and safety evaluation of six to get the best for extraction of freshwater algae. The results show that with acetone: ethanol=1:1 mixture of extraction agent to do in 21℃, extraction, extraction effect. And "Water and wastewater monitoring and analysis methods" in the extraction methods, the ultrasonic extraction with extraction speed, time is short, extraction rate, and environment protection.2. A method for the determination of chlorophyll a in chlorella by ultra sound extraction and synchronous fluorescence spectrometry with constant-wavelength interval of 216 nm is developed. The linear range is 0.02-1.25 mg/L with the detection limit of 1.6μg/L. The recovery is between 97.0% and 104%. By comparison with the visible spectrophotography, they have not significant differences.The method is quick and sensitive. Other common pigments do not interfere. It can meet the demands of testing green algae.3. A new method is described for the determination of chlorophyll a in green algae by derivative synchronous fluorescence spectrometry. The method is quick and sensitive. No complicated sample pretreatment is required. The linear range of the chlorophyll curve for anabaena is 0.02-125μg/L with a detection limit of 0.25μg/L. The recovery range is between 97.0% and 104%. Derivative synchronous fluorescence spectrometry and fluorescence wears comparison, the synchronous fluorescence method in the United derivative technique, the peak shape is more prominent, more conducive to distinguish, especially when the analyte concentration is low, more the weak signal separate from the complex background to; chlorophyll a derivative synchronous fluorescence signal independent of the influence of chlorophyll b, with a distinction between the fine structure of spectral changes, to identify multi-component spectral overlap and enhance the clarity of the secondary benefits, further reducing interference.