Stereoselective separation of MDMA enantiomers in sewage water

In 2011 a European campaign was executed to estimate the daily loads
of drugs of abuse into sewage treatment plants (STP) of 19 European
cities. During one week every day a representative 24h composite
sample of the influents was taken. For one particular case, the city of
Utrecht, an abnormally high load of MDMA was encountered. The
levels of MDMA found did not correspond with those observed in the
previous year 2010. The samples were measured by HPLC-LTQOrbitrap-
MS, and calculated loads varied from 350 g per d for the first
day to 75 g/d for day seven. Compared to the preceding year the levels
were 35x higher on average. The results raised suspicions about the
origin of these loads. The Netherlands and Belgium are known for being
the major producers of MDMA in the world, according to information of
the EMCDDA. After viewing police reports on the internet it became
clear that a possible cause for the abnormally high levels could be a
police raid into a private home two days before the sampling started.
The location raided appeared to be equipped for producing MDMA
tablets, but only additives, empty tablet bags and a few tablets were
found. MDMA is produced as a racemate. When swallowed, it is
transformed during passage through the human body. However, the rates
of transformation of the two enantiomers of MDMA are different in the
human body. The S-enantiomer is transformed at a slightly higher rate
than the R-enantiomer, resulting in a shift in the enantiomer fraction
from racemic (0.5) to =0.65. The enantiomer fractions for all samples
from the campaigns in 2010 and 2011 were measured using chiral
chromatography on CBH columns and triple-quadrupole MS detection.
The results showed that the samples from 2011 invariably had
enantiomer ratios fractions close to 0.5, demonstrating that the observed
MDMA in these samples is racemic and therefore could not be subjected
to human metabolism. It can be therefore concluded that MDMA
originated from direct disposal into the sewer. The total amount of
MDMA that was disposed in the sewage system was assumed to be 30
kg equivalent to approximately 500,000 tablets. As MDMA is not
removed at all in the STP plant of Utrecht the amount discharged is
directly transferred to the environment. The implications of these direct
discharges for ecosystem health remain largely unknown. The present
study demonstrates the potential of sewage analysis by LC-MS methods
and that of chiral separations for forensic purposes.