(312f) Real-Time Membrane Permeability Measurements of Hydrogen Sulfide and Acetone

The permeability of membranes plays a critical role in many
physiological as well as industrially relevant processes. Significant laboratory
data already exist on the permeability of a number of molecules in a variety of
membranes. However, rapid on-site measurement of permeability in real-time is
of interest because: (1) membrane characteristics change during processing and
use and (2) the need for quality control during high throughput engineering.
Development of synthetic membranes is a rapidly growing area of research and
development, driven by the variety of biomedical applications, from skin
substitutes to organ tissue.

Among the molecules of interest in physiological processes are hydrogen
sulfide, a hydrophobic molecule, and acetone, a highly water-soluble molecule. We
will here present membrane permeability measurements of these molecules obtained
utilizing an innovative combination of electrocatalytic and colorimetric
methods that is amenable to miniaturization, portability, and the ability to
measure at low parts-per-billion levels. 
Measurements have been performed in both synthetic membranes and animal
skin. The figure below is an example of measurements made of permeation rate of
hydrogen sulfide through a 25 mm thick synthetic membrane having very low permeability. Details of the
measurement systems and apparatus as well as results of the measurements will
be presented.  The authors will also
discuss how the observations can be applied to several biomedical and
analytical approaches.