In June 2009, the Laboratory in hydrology of Nancy (Ansès-LHN, Nancy) conducted an
exploratory inter-laboratory proficiency tests (ILT) test in collaboration with the
AQUAREF network to identify laboratory practices and estimate inter-laboratory uncertainty
for the compounds under study. There were a total of 12 compounds belonging to six
families (hormones, antibiotics, non-steroidal anti-inflammatory drugs, beta blockers,
antipsychotics and others) including one compound used in veterinary medicine. It was the
first ILT conducted in France on water intended for human consumption. Thirty-one
laboratories participated, 4 of which were located abroad.