インライン還元―蛍光検出HPLCを用いる多環芳香族炭化水素キノン分析法の改良と大気粒子抽出物への適用

摘要

A simple and sensitive method for measuring quinoid polycyclic aromatic hydrocarbons (PAHQs) in soluble organic fraction (SOF) of airborne particles based on two-dimensional high-performance liquid chromatography (HPLC) with fluorescence detection was established. The system involves a reversed phase column with naphtylethyl groups bonded silica packing material for sample clean-up, a 6-port switching valve, an ODS column for trapping the fraction containing PAHQs, a reversed phase column with cholesteryl groups bonded silica packing material for sample separation, and a Pt-Rh catalytic column for the reduction of PAHQs to a corresponding fluorescent compound. The accuracy of the assay, as applied to airborne particulate sample extracts spiked with known amounts of PAHQs were 91 – 107%. The detection limits were 19 to 2000 fmol per injection (signal-to-noise ratio = 3), and the calibration range was from 1 to 100 pmol with excellent proportionality (R2≥0.9992) for four kinds of PAHQs: benz[a]anthracene-7,12-dione, fluoranthene-2,3-dione, pyrene-1,6-dione, and pyrene-1,8-dione. PAHQs in SOF of airborne particles collected in Kyoto, Japan were successfully measured using the established analytical method with simple sample-preparation steps: ultrasonic extraction in organic solvent and concentration under reduced pressure and/or a nitrogen stream.