[Nitrated polycyclic aromatic hydrocarbons (nitro-PAH) in suspended particles in the atmosphere. 1. Fractionation and analytic detection].

A procedure to determine nitrated polycyclic aromatic hydrocarbons from suspended particulate matter was developed. Depending on the organic amount needed, different prefractionation steps are described, starting from thin layer chromatography and solid phase extraction by a cartouche system for small amounts, reaching over column chromatography to preparative HPLC for extracts corresponding up to 1000m3. Prior to analysis Nitro-PAH were reduced to the corresponding amines by a modified method given by Jäger. After reduction these amines could be trapped selectively by ion change chromatography and eluted as a pure fraction with a mixture of methanol/isopropylamine 1/1. This mixture can be easily evaporated and the sample is redissolved in acetonitrile/water 80/20, buffered at pH 7.2 by 0.1 M Tris-buffer. 20 microliter of that solution is injected in a HPLC system with a reversed phase column (250 x 4 mm, 5 micron) and fluorescence detection. According to the strong fluorescence properties of amino-PAH detection limits of 5-50 pg could be achieved. Thus, depending on the preconcentration factor (up to 100 m3 per 200 microliter) these compounds could be detected in the range from 0.5-5 pg/m3.