Mining Spreadsheet Complexity Data to Classify End User Developers

In a denuder (2) serving as a gas collection apparatus, an absorption liquid supply tube (4) for spraying absorption liquid from a nozzle (4a) to the inner wall of a denuder pipe (2a) is provided at the upper portion of the denuder pipe (2a). A sample atmospheric air supply tube (7) for supplying sample atmospheric air into the denuder (2) is provided at the lower portion of the denuder pipe (2a). On the inner wall of the denuder pipe (2a) is formed a photocatalyst thin film layer (13) containing photocatalyst which is optically excited to be made super-hydrophilic upon irradiation of light having specific wavelengths (for example, ultraviolet rays) thereto.