Effects of experimental conditions on the determination of the effective carbon number

The response of the flame ionization detector (FID) is proportional to the carbon number of hydrocarbon molecules; however, heteroatoms attached to the carbon chain can decrease the defector's response. Sternberg was the first who determined the effective carbon number increments (ECNinc), which show how different atoms contribute to the response of a molecule as a whole. If the extent of the contributions of different atoms or functional groups to the FID response of a molecule is known, one could calculate the relative response of analytes not available as a pure, authentic standards. An accurate and reliable quantitative analysis requires an accurate determination of ECNinc. The effects and parameters influencing the ECNinc value have to be examined. Sternberg determined the effects of the detector geometry and of the parameters to the response. However, we assume that other experimental conditions can indirectly also affect the ECN contributions. In this study the effects of the temperature of the injector, detector and column and of the injection modes were investigated. We compared the ECN values obtained at different concentrations and measured them with different hydrocarbons as the internal standards.