Biotests with Higher Aquatic Plants

OECD Method 221 [34] has been available since 2006 and is a growth inhibition test for Lemna minor, the small water lens. The test uses a defined number of fronds of Lemna plants which float on top of an aqueous sample and are incubated for 7 days increase in the number of fronds and increase in biomass are measured. Like 

7 Evaluation of Bioassay Results Obtained from Samples of Complex Composition 

Most of the standardised ecotoxicity methods recommend the use of synthetic or other well-known and fully defined control matrices. The control is needed to detect the behaviour (growth, survival) of the test organisms in the absence of toxic or harmful agents. These results are the reference values, defined as 0% inhibition or 100% vitality, and are the basis for the calculation of sample inhibition. 

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