The development of a method for the determination of the oxygen amount in organic liquids is described using a new device made by a vertical pyrolysis unit linked to a non-dispersive CO infrared detector. The outcome signal is amplified using an additional electronic conversion card monitored by homemade software. This system allows for the quantification of oxygen in a range from 0.5 wt % oxygen to a limit of 001 wt % oxygen when applied to standard solutions (model oxygenate containing compounds in toluene). Linearity tests Were carried out on different oxygen model solutions containing molecules representative of biomass-derived matrices. The method provides relative good results when applied to a biomass product, such as a partially dehydroxygenated biomass fast pyrolysis oil. The most relevant aspects of the study are reported.