Sampling and Analytical Methods for the Determination of Monochloroacetic Acid in Air

A personal sampling and analytical method has been developed for the determination of monochloroacetic acid (MCA) vapor in air. The sampling procedure is the collection of MCA with a solid sorbent sampling tube packed with silica gel. The MCA is leached from the exposed sorbent into distilled, deionized water and quantitated by ion chromatographic analysis. The method has been validated in the concentration range of 0.35 to 29 mg/m3 in 3-L air samples. The capacity of the silica gel is in the range of 3 to 4 mg of MCA per 100 mg of sorbent, which allows for up to 8 hr of sampling at concentrations greater than 40 mg/m3. There are no significant interferences from glycolic acid, acetic acid, dichloroacetic acid, trichloroacetic acid, fluoride and chloride compounds, or water vapor. The effects on the analytical data due to variations in the temperature and humidity of the test atmosphere, sample storage time and chromatographic parameters have been found to be minimal.