Recent progress in our understanding of biofuel production has increased the demand for the development of various technical methods for the quantification of biofuel candidates such as neutral lipids and polar lipids such as fatty acids. The keys factors required for increasing biofuel and biorefinery production are biological, particularly how to isolate highly productive microalgal strains and technological and engineering systems to establish highly energy-efficient high-cell-density-mass cultivation. For establishing such systems, the development of analytical methods which are useful for easy and rapid quantification of biofuel compounds is necessary.
FT-IR is very useful for getting relative quantification data of organic cellular components such as proteins, carbohydrates and lipids in non-disrupted cells. On the other hand,TOC analyzer can be used for the quantification of total organic and inorganic carbons in samples. Therefore, the combination of both FT-IR and TOC analysis was expected theoretically to enable us to get quantities of individual cellular organic components. However, it is impossible to quantify all cellular organic components by FT-IR although it does provide relative amounts of most major cellular organic components. Therefore, we sought to develop a new method to get “semi-quantitative values” of major cellular components.