SAMPLING OF AIR FOR DETERMINATION OF HYDROGEN CYANIDE

Abstract

For sampling of hydrogen cyanide (HCN) gas in atmospheric air, a midget im-pinger containing NaOH aq. as absorbing solution was found to be the most suitable apparatus. The efficiency of sampling for HCN was affected by the absorbing con-ditions greatly. In this procedure, NaOH in the solution were consumed by CO2 in atmospheric air gradually1). To absorb HCN thoroughly, it was necessary to keep enough NaOH in the solution. The solution containing CN'-compounds generated HCN gas, if the alkalinity of the solutions was lost. Beside these, various other conditions also had to be considered to absorb CN'-compounds in atmospheric air.