Quantitative infrared spectroscopy of lipids in solution: I. Theoretical and practical aspects of the new method

In Part I of this series, new data for quantitative infrared spectroscopy of pure lipids are reported for various frequency regions. A new analysis of previously reported infrared data demonstrates that the E1 percent/1 cm concept, long in use in ultraviolet studies of proteins, is applicable to the analysis of lipids of the infrared. It is shown that integrated absorbance measurements over optimal limits of the C-H-stretching region are substantially more sensitive than those of the C-H-bending region. It is shown that the new method is more sensitive and specific than gravimetric methods currently in use.