Application of automatic calculation of Kováts retention indices to evironmental analyses by gas chromatography —mass spectromety-—calculator

Abstract

Automatic calculation and plots of Kovát' retention indices (RI) from gas chromatographic (GC) analysis of environment samples is provided by a calculator- controlled GC—mas spectrometric (MS) system. The retention indices framework of carbon numbers is set up using a standard sample containing all the desired n-hydrocarbons which are automatically identified in a GC—MS run by the presene of the m/e 85.1 C 6H 13 + ion and the molecular ion. These standard retention data are used to automatically calculate RI values for samples extracted from airborne particulate matter run under identical GC conditions. n-Hydrocarbons present in a sample can be employed as internal standards but an editing subroutine may be necessary to remove ambiguities. Standard deviation of a test of the external standard method is 2.4 RI units, of the internal standard method 1.5 RI units.