Injection principles in capillary gas chromatographic analysis of bacterial fatty acids

Principles for sample injection in fused silica capillary gas chromatographic analysis of bacterial cellular fatty acids are discussed. Comparative analyses were made of the methyl esters of fatty acids in a reference solution and in Legionella pneumophila serogroup 1, using both split and splitless injection. A splitless injection technique, in which the methyl esters are cold-trapped immediately after injection and consecutively released in accordance with temperature programming, gave sensitivity increase corresponding to the split ratio used in split injections, without diminishing the speed of analysis or separation efficiency. Splitless injection, utilizing cold-trapping, can be recommended for capillary gas chromatography in routine profiling of bacterial fatty acids.