In recent years Relaxed-Eddy-Accumulation (REA) methods have become an important tool in micrometeorological studies. The advantage of the REA technique over the Eddy-Correlation method is its combination of slow trace gas analyzers with fast sonic anemometers that allows determination of fluxes for a wider range of trace gases. This application is in particular a powerful tool for species such as biogenic volatile organic compounds (BVOCs) that usually require time consuming preconcentration steps prior to their analysis. REA applications using adsorption tubes for sampling BVOCs on site and subsequent analysis in the lab have already been reported. However, this experimental design displays several disadvantages commonly associated with adsorption tubes, among them: (1) necessity for a large number of adsorption tubes in order to cover measurement campaigns of several weeks. In addition this procedure requires careful handling of possible different properties of each tube. (2) Storage and transport problems that might mask the BVOC-results and represent another possible technical flaw. This paper presents a novel REA technique for the determination of BVOC-Fluxes using an online gaschromatographic analysis system at the measurement site itself thus minimizing the disadvantages mentioned above. In the meantime the system has been quality assured. In this presentation the experimental setup will be described and results from measurement campaigns will be discussed.