Improved Efficiency of Desorption of Oxygenated Solvents from Activated Charcoal Using a New Polar Additive to Carbon Disulfide

Abstract

In industrial operations where workers may be exposed to a mixture of polar and nonpolar organic vapors, such as in spray painting, the use of carbon disulfide as the desorption liquid for charcoal tubes or diffusion badges is inadequate. Desorption efficiencies for some polar analytes may be low, and a loading dependency of the desorption efficiency may be present, making quantitation difficult. Many researchers have added polar substances to carbon disulfide or used alternative polar desorption solvents or schemes; however, often the polar additive or solvent may be a compound of interest or interfere in some way with the analysis.

Numerous polar and nonpolar solvents were found on charcoal tube and diffusion badge samples collected during automobile assembly spray painting operations. Methanol in carbon disulfide was tried as a desorption solvent but was found to be inadequate. Considerable improvement in desorption efficiencies for the polar analytes was obtained when 2-(2-butoxyethoxy) ethanol in carbon disulfide was used as the desorption solvent for charcoal tubes. This mixture also improved the desorption efficiencies for polar compounds collected on diffusion badges, but to a lesser degree. The 2-(2-butoxyethoxy) ethanol eluted late in the chromatogram, several minutes after the last analyte. The optimal concentration of 2-(2-butoxyethoxy) ethanol in carbon disulfide was found to be approximately 5 percent (v/v).