Any body can give article showing high LC 50 value compared to static renewal test?
Generally it means that the tested compound is partially lost during the test. Could be sorption, volatilisation or degradation. Remember higher LC50 means less toxicity from the nominal dose added.
I completely agree with Henrik. In most cases, changes in LC50 values are related to changes in actual concentrations. One example where an additional exposure took place is attached as link; in this case, daphnia probably "ate" addtional TiONP in the semi-static test. Maybe you could use the discussion of test design comparison for your work.
http://www.sciencedirect.com/science/article/pii/S0166445X12002962
is there any relation ship with salinity and toxicity ? my experiments were at salinity of 30
Salinity can play a role depending on the test organism and chemistry of the tested chemical. There is no connection between this and the difference between static and continuous flow through tests.
Is the concentration in static renewal given as nominal or was it analytically determined? (Guidelines require analytical check of nominal concentration; only if the deviation of analytically determined concentration is within defined values, nominal concentration may be used for LC50.)
Salinity could have a connection with the static vs flow through tests if the salinity changes over time due to evaporation however this is normally unlikely.
Besides the previously mentioned possibilities the sensitivity of an animal might not be the same if it is exposed to (several) peak concentrations or a continious exposure (both with an equal mean exposure concentration)
- Badges
- Science method
- Similar topics
- Biological Science
- Ecology