Photoacoustic Determination of Total Carbon Deposits

Abstract

Carbonaceous particles, a major constituent of submicron atmospheric aerosols, have been related to visibility degradation and adverse health effects. Various efforts based on thermal combustion, optical transmittance, nuclear excitation, solid phase photoacoustics and wet chemistry have been made to develop analytical methods to determine elemental and organic carbon, and total carbon values.(1) The technique described here is applied only to total carbon measurements and utilizes a three step process consisting of: 1) carbon combustion to CO2, 2) cold trap preconcentration and 3) gas phase photoacoustic detection. The primary design criteria for this system are simplicity and low cost rather than high precision and low detection limit.