speed test with E test kit

Recently a friend had in possesion some really, really strong meth, unlike anything he had ever tried before. When it was tested with marquis it went orange-brown, only just, and very slowly, like it was very weak. When it was tested with mandelin, it went yellow green in much the same way. I understand that this was not the designed purpose for these testers, but I'm still a little surprised, can anyone shed any light on this or offer similar stories?

well we always say that the testers are not there to give an indication of the strength of substances, they can only indicate the presence of a drug. i admit that strong speed usually gives a fast reaction, but i'm not sure what this means in your case. sorry, i don't think i've been much help.
[ 01 May 2002: Message edited by: johnboy ]

Sounds like it could be time to change testers. Old testers or those that have not been stored properly loose their strength over time and the reaction becomes greatly slowed.

Okay, I don't exactly know the chemical kinetics of the reaction of meth with the reagents... maybe someone with a bit more knowledge can help you(I'm suspecting a second order reaction? or something? Kinetics isn't my strong point.), but what my hypothesis is that the reagent you use will always slowly change colour due the the chemical nature of the meth, and the purity won't change it.
Also, the speed and nature of reaction is unimportant. The important thing is that a reaction DID occur, and it was the colour you were looking for, and nothing else.