To answer your actual question Verbal, yes it does.
If you tested two known samples of an amphetamine like 'street' speed (as opposed to the pharmacy prescribed version
), one very strong and one quite weak, you will see two very
marked differences.
In the strong sample, the reaction may be a fizzing and/or a
rapid colour change to a deep orange/red. In the weaker sample, no fizzing and/or a
very slow change to a weak yellow/brown/orange occurs. This difference in reaction speed is repeated across most all popular street drugs used with the Marquis Reagent.
In this way, we can begin to tell the difference in indicated strengths between samples of E, speed and others substances.
As AJ is very fond of repeating, the speed of the reaction won't tell you if you have a sample of MDMA in your hands. But let's face it: Marquis reagent (as found in 'E' and the 'EZ Test') is used for a lot more than just testing ecstasy, and so yes, the speed of the rection seen
can indicate either a greater or lesser concentration of the drug sample under observation.
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Drugs are the answer, now what was the question?....