Collection of nitrogen dioxide by porous polymer beads.

An air sampling method is described which utilizes a porous polymer, Porapak Q, which reacts specifically with nitrogen dioxide. This material has a high capacity for nitrogen dioxide, and the reaction product can be hydrolyzed to yield nitrite in the hydrolyzate. Direct reading indicator tubes were constructed, and the length of color change was found to be directly proportional to the concentration of nitrogen dioxide passed through the tube. This porous polymer is an efficient air-purifying element for the removal of nitrogen dioxide and can be reactivated.