The certified methodology (Nmet) implementing the contract No. 201301009 dated 16 December 2014. The methodology describes the method for effective passive sampling of polybrominated diphenylethers and other hydrophobic organic compounds (hexabromocyclododecane, new brominated flame retardants) in aquatic environment which allows the quantification of freely dissolved concentrations of these substances in the water column in the surface water at a concentration level of less than 1 pg l-1. The methodology is helpful for users of passive sampling methods who want to realize the passive sampling of brominated flame retardants and other hydrophobic contaminants in aquatic environment in their research or monitoring of pollutants. It is intended especially for companies and institutions dealing with quality of the aquatic ecosystem. In Czech Republic are there State companies of the Basin, Czech Hydrometeorological Institute, and companies responsible for drinking water quality. The methodology was certified on 22 December 2017 by the Ministry of the Environment and published in its Buletin 1/2017.