A method for determining the excretion of volatile substances through skin.

A method is described for determining the concentration of volatile substances that are excreted through the skin via insensible perspiration. The technique involves placing the hand into a polyethylene bag maintained at 37 degrees C and allowing the air around the hand to come to equilibrium with the vapors emanating from the skin. Gas samples were removed from the bag and the concentration of volatile substances was determined by gas chromatographic analysis. Using ethanol as a test substance, alcohol excretion from the skin was determined and compared to breath and blood concentration. The results indicate that the concentration of alcohol in insensible perspiration is not substantially different from that of breath or blood following complete absorption. However, during the period of active drug absorption, perspiration alcohol concentration lags behind the blood and breath concentration, and then later has a slightly higher concentration than blood and breath.