An Automated Temperature Control and Data Acquisition System for Fourier Transform Infrared Studies: Application to Phase Changes in Hydrocarbons and Lipid Bilayers

Abstract

As a means of facilitating temperature-dependent FT-IR studies of liquid samples, a simple, accurate, efficient, and versatile system for automated thermoelectric temperature control and UNIX-based data acquisition is described. With the use of this system, phase changes in an n-alkane, pentadecane, and an aqueous dispersion of a phospholipid, dipalmitoylphosphatidylcholine, were characterized. The combination of precise temperature regulation, ability to quantitate very small changes in the infrared bands, and careful control of the thermal history of the sample reveals subtle changes in the physical structure of these molecules in a reproducible manner.