Oxythermography Method for Assessing Passive Adsorption of Organic Compounds on Surfaces of Solid Materials to Evaluate the 14C Contribution to the Background

The method for investigating passive adsorption of organic compounds from the indoor air on surfaces of solids is proposed. The method is based on detecting organic matter on the surface of the material using oxythermography after keeping the material in the indoor air for a certain time. The method evaluates the total amount of carbon on the surface of the material and assesses the ¹⁴C contribution of organic substances adsorbed on the surface to the radiation background in low-background experiments. The method has been tested in laboratory rooms of two different institutions. The total amount of organic substances adsorbed on the surface of platinum, palladium, and fused silica has been evaluated after keeping the samples in the indoor air for 10 minutes to 34 days. The differences in adsorption have been observed, and they depend on the material composition of the surface and the class of the cleanrooms where the experiments were performed. The method allows examining the samples without transferring them elsewhere.