THE TESTING OF CARBON SORBENT FOR PRECONCENTRATION OF VOLATILE ORGANIC TRACE COMPOUNDS

Carbon sorbent Carb I (prepared by controlled pyrolysis of saccharose) was tested for preconcentration of volatile organic compounds from the gas phase. The model mixture of hydrocarbons (n-alkanes and aromatics) and mixture of aromatics with low-boiling polar solvents was used. For desorption of compounds several solvents were utilized, carbon disulfide was found to be the best. Adsorption-desorption process was studied in the concentration range of components in nitrogen 0.03-15 mu g dm(-3). Chromatographic measurements were performed on gas chromatograph with on-column and splitless injection, fused silica capillary columns with chemically bonded stationary phases under temperature programmed conditions and flame ionization detector. The recovery of n-alkanes and aromatics was found to be around 90 %, the recovery of low-boiling solvents, particularly of polar character was low.