Fatty Acid Determination Using Gas Chromatography

Introduction :

Gas chromatography is a technique for carrying out the separation and measurement of

mixtures of materials that can be volatilized. These materials may be gases, liquids, or solids that have appreciable vapor pressures at temperatures up to a few hundred degrees.

In capillary gas chromatography a stationary phase, generally a stable non-volatile liquid, is spread in a thin film on a wall of column. A carrier gas acts as an inert moving phase to transport the sample components from an injection port at the head of the column through the column to a detector.

Sample injection is an arrangement by which a solid, liquid, or gaseous sample is transmitted as

a short pulse into the carrier-gas stream before it enters the column. The sample should be vaporized and carried to the leading end of the column in negligible time. The detector, commonly flame ionization, monitors the composition of the carrier-gas stream as it leaves the

column.

Simple, sensitive, and stable, the flame ionization detector has contributed in a major way to the explosive growth of gas chromatography. A significant advantage is that it provides a recorder response proportional to concentration of substance in the effluent from a column.

One area of current public interest is nutrition, specifically, the fat content of food. Obesity, diabetes, and cardiovascular disease, along with their related complications, are increasing in America, Europe, and in other parts of the world. However, it is not only total fat, but also the type of fat that must be considered. Some ‘good fats’ are required for biochemical processes or necessary for dissolving fat-soluble vitamins. Other ‘bad fats’ accumulate in the cardiovascular system, potentially leading to health problems.

Each type of fat has unique physical (such as boiling point) and chemical (such as degree, location, and configuration of unsaturation) properties. Because of this, different analytical methods are required to...