Stability of 3,4-methylenedioxymethampetamine (MDMA), 4-methylmethcathinone (mephedrone) and 3-trifluromethylphenylpiperazine (3-TFMPP) in formalin solution.

Occasionally, the only postmortem samples available for analysis are contaminated with formaldehyde, either due to embalming prior to sampling or because analysis is carried out only when formalin-fixed tissues retained for histological study are available. Formaldehyde reacts with several drugs of forensic interest that contain either a primary or a secondary amine group to form their N-methyl derivatives. We investigated the stability of 3,4-methylenedioxymethampetamine (MDMA), 4-methylmethcathinone (mephedrone) and 3-trifluromethylphenylpiperazine (3-TFMPP) in formalin solutions using three different formaldehyde concentrations (5, 10 and 20%) and three different pHs (3.