An oxythermographic method for determining passive adsorption of organic compounds on the surface of solid materials in order to account for the background generated by ¹⁴C

A method for studying passive adsorption of organic substances on the surface of solids from room air is proposed. The method is based on the oxithermographic determination of organic matter on the surface of the material under study after the material has been in the room air for a fixed time. The method allows the total amount of carbon on the surface of a material to be determined and the contribution of 14C in low background measurements from surface organic matter to be estimated. The method was validated in laboratory facilities of two different organizations. The total content of organic substances extracted on the surface of platinum, palladium and quartz was determined after the samples had been exposed to air from 10 min to 34 days. Differences in adsorption were revealed depending on the composition of the surface material, as well as the cleanliness class of the premises where the analysis is carried out. The method allows carrying out studies without transporting samples to other rooms.