EFFECT OF SOLVENT POLARITY ON THE DETERMINATION OF OXO-POLYCYCLIC AND NITRO-POLYCYCLIC AROMATIC-HYDROCARBONS USING CAPILLARY GAS-CHROMATOGRAPHY WITH SPLITLESS INJECTION

The importance of solvent polarity in the injection conditions for the determination of oxo- and nitro-polyclic aromatic hydrocarbons in capillary gas chromatography was investigated. When standard solutions Of these compounds were analysed by high-resolution gas chromatography using splitless injection, peak splitting with two or more maxima was obtained when methanol and acetonitrile were used, in the preceding steps no peak splitting was observed with dichloromethane or acetone. This splitting can be eliminated using a retention gap or by increasing the initial column temperature. Response factors for all these compounds at different initial temperatures and different solvents were studied. The best results were obtained using acetonitrile, an initial temperature of 60-degrees-C and a retention gap. Reproducibility gave a relative standard deviation from 1.8 to 6.7 when measured by peak area; detection limits (signal-to-noise ratio of 2:1) using a flame ionization detector ranged from 129 pg for 2-methyl-1-nitronaphthalene to 1.5 ng for 9, 10-phenanthroquinone.