rbishop,
don't need a study..it's basic chemistry. (btw I have 3 years of organic and bio chemistry in my back ground )
think about it.. water is pretty dense..when you add a chemical to it you need to seriously aggitate/mix the water.
IE:
if you take a mix of saltwater and introduce the saltwater to freshwater..you will be able to see it as it is introduced. it's almost like a cloud..this is basically what happens when you introduce the de-chlorinator then add water..it will eventually mix but it does not mix instantly..
ever read the label on prime? "May be added to aquarium directly, but better if added to new water first. If adding directly to aqaurium, base dose on aquarium volume"
adding it to new water first allows the prime(in this case) to start the de-cholination process prior to adding it to the tank.
but like I said..the impact of any chlorine is minimzed by multiple factors..
one the fact that the chorine/chloramine is 'dilluted
two..added dechlorinator will eventually do what it is designed to do.