A high-performance liquid chromatographic system equipped with on-line reducer, clean-up and concentrator columns for determination of trace levels of nitropolycyclic aromatic hydrocarbons in airborne particulates

A HPLC system with on-line reducer, clean-up and concentrator columns has been developed for determining nitropolycyclic aromatic hydrocarbons (NPAHs). Maximum efficiency of the reducer column (Pt/Rh-coated alumina) was achieved after the column was activated with a flow of air/hydrogen at 350°C for 3 h and when ethanol¯acetate buffer was used as the sample carrier solution. After a benzene¯ethanol extract from airborne particulates was washed with sodium hydroxide, sulfuric acid and water, an aliquot was injected into the system. NPAHs were separated from interfering substances by the clean-up column and reduced to their amino derivatives by the reducer column. The derivatives were concentrated on the concentrator column and eluted into the separator column. NPAHs such as 1,3-, 1,6-, 1,8-dinitropyrenes and 1-nitropyrene were determined chemilumigenically with linear calibration graphs from 1×10-11 to 1×10-8 and 1×10-10 to 1×10-7 M, respectively, at an injection volume of 100 mul. These NPAHs in airborne particulates were determined by the proposed method.