Determination of airborne particle-associated benz[a]anthracene-7,12-quinone using high-performance liquid chromatography with in-line reduction and fluorescence detection

A simple and sensitive method for measuring airborne particle-associated benza]anthracene-7,12-quinone (BaAQ) based on two-dimensional high-performance liquid chromatography (HPLC) with fluorescence detection was established. The system involves an ODS column for sample clean up, a 6-port switching valve, an ODS column for trapping the fraction containing BaAQ, an ODS column for sample separation, and a Pt-Rh catalytic column for reduction of BaAQ to a corresponding fluorescent compound. The accuracy of the assay, as applied to airborne particulate sample extracts spiked with known amounts of BaAQ was 94–108%. The detection limit was 97 fmol per injection (signal-to-noise ratio = 3), and the calibration range was from 1 to 100 pmol with excellent proportionality (R² = 0.9995). BaAQ in airborne particles collected in Osaka, Japan every 3 h was successfully measured using the established analytical method with simple sample preparation steps: ultrasonic extraction in organic solvent and concentration under reduced pressure and/or nitrogen stream.