Determination of Water and Volatile Organics in Filter Collected Aerosols

Abstract

A simple technique has been developed to measure the water content in filter collected aerosols using a gas chromatograph. Simultaneously the method can determine semi-quantitatively the total organics that are volatilized from the collected aerosol at approximately 110°C. To illustrate the procedure, samples of aerosols collected from Southern California suburban air on two different winter days have been analyzed and were found to have a water content ranging from 1.7–6.2%. Detection limits of 20μg water are projected for a glass fiber filter medium. Tests of the equilibration to changes in relative humidity show that the weight of the filtered material responds rapidly to variations in water vapor of the surroundings. Thus, care must be taken in sample handling to insure that the measurements have relevance to conditions in the ambient atmosphere.