Volume 125 (2017) Issue 3 Pages 175-179
Silica gel is commonly used as a sampling agent in small glass tube products for work environment measurements of organic solvent vapor, as established by the Industrial Safety and Health Act in Japan. However, to date there has been no national standard for sampling tube products, and the extraction efficiency of adsorbed organic solvent vapor from silica gel significantly affects the accuracy of measurement. Here, we have investigated the material properties of silica gel used in typical Japanese sampling tube products, and the effects on the efficiency as determined by the phase equilibrium method. This study focused particularly on specific surface area, porosity and grain diameter of silica gel specimens.