Determination of Chlorophyll a Content
The standardized test procedure in accordance with the DIN 38412-L16 norm is used for the evaluation of the chlorophyll a content in surface bodies of water. The chlorophyll content in a water sample may yield information regarding the trophic condition of a body of water. This value, along with other biomass and bioactivity parameters, provides information about the quantity and metabolic potential of the phytoplankton in water bodies.
Chlorophyll a is an essential pigment for photosynthesis in all green plants. The determination of the chlorophyll a content is based upon the spectrophotometric measurement of an extract of the filter residue of a water sample. The original chlorophyll content is deduced through the comparative measurement after quantitative transfer of the chlorophyll in phaeopigments.
This procedure can be applied in any superficial bodies of water where phytoplankton grows. It is suitable for the evaluation of the productivity of waters as well as for the quantification of the algae biomass (cell proliferation), for instance through substances released in the water.
The determination of the pigment content of benthic algae or of sediments requires a modification in the sampling procedure.