Abstract: As chlorophyll-a (Chl-a) is used to characterize phytoplankton biomass, its content in a waterbody is commonly used as an indicator of eutrophication level of the waterbody. Although there are a number of measurement procedures currently in use, not a unified standard method is developed. A retrospect is presented here of the development history of the methods for determination of Chl-a. On such a basis, a comparative study was done of the methods in cell discruption technique and type of extractant. By comparing advantages and disadvantages of the various determination methods, a relatively effective method, hot-ethanol method, is proposed. This method is easy to operate, high in extracting rate, stable, reliable and harmless to human health. Besides, a brief introduction is presented the three commonly-used determination methods, i.e. spectrofluorometry, high efficiency liquid chromatographic and spectrophotometry, and their respective procedures, applicabilities, advantages and disadvantages. The comparison demonstrates that the combination of the hot ethanol extraction method with the spectrophotometry is a good method, worth extrapolating. It is expected that the review may provide some bases for development of a standard method for determination of Chl-a concentration in China.

Key words: chlorophyll-a, extracting solvent, hot-ethanol extraction, spectrophotometry