Under request by Directorate General  for Health and Consumers (DG SANCO) a  collaborative trial, IMEP-115, was conducted in  accordance with in  ternational protocols  by the European Union Reference Laboratory  for Heavy Metals in Feed and Food  (EURL-HM), to determine the performance char  acteristics of an analytical method for  the determination of methylmercury in seafood.  IMEP-115 was organised in support to th  e Commission Regulations 1881/2006 and  882/2004. The method is based on a  double liquid-liquid extracti  on, first with an organic  solvent and then with a cysteine solution. The fi  nal quantification is done with a direct  mercury analyzer.  The repeatability relative standard deviation (RSD  r  ) ranged from 3.9 to 12.3 % while the  reproducibility relative standard deviation (RSD  R  ) ranged from 8.4 to 24.8 %.  The method demonstrates to have acceptable prec  ision for all test materials, thus it fit  for its intended analytical purpose.  Detailed information on the organisation and  outcome of the collaborative trial, IMEP-  115, can be found in the report EUR 25830 EN 2013 [1].