A method for determining the excretion of volatile substances through skin

Area of Science:

• Analytical Chemistry
• Dermatology
• Pharmacokinetics

Background:

• Volatile substances are excreted through the skin via insensible perspiration.
• Quantifying these substances is crucial for understanding physiological and toxicological processes.
• Current methods for analyzing skin volatiles are limited.

Purpose of the Study:

• To develop and validate a method for determining volatile substance concentrations in insensible perspiration.
• To compare skin perspiration alcohol levels with blood and breath alcohol levels.
• To investigate the pharmacokinetics of alcohol excretion through the skin.

Main Methods:

• A hand was enclosed in a polyethylene bag at 37°C to equilibrate with skin vapors.
• Gas samples were collected from the bag.
• Volatile substance concentrations were analyzed using gas chromatography.
• Ethanol was used as a model substance to validate the method.

Main Results:

• The concentration of ethanol in insensible perspiration was comparable to breath and blood alcohol levels after complete absorption.
• During active absorption, perspiration alcohol levels lagged behind blood and breath levels.
• Perspiration alcohol concentrations were slightly higher than blood and breath levels post-absorption.

Conclusions:

• The described method effectively measures volatile substances in insensible perspiration.
• Skin excretion of alcohol correlates with blood and breath alcohol concentrations, with distinct temporal dynamics during absorption and post-absorption phases.
• This technique offers a non-invasive approach for monitoring systemic exposure to volatile compounds.