DETERMINATION OF DIAMINOPYRENES AND AMINOPYRENES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH CHEMILUMINESCENCE DETECTION

A high performance liquid chromatographic (HPLC) method with chemiluminescence (CL) detection was developed for the sensitive determination of 1,3-diaminopyrene (1,3-DAP), 1,6-DAP, 1,8-DAP and 1-aminopyrene (1-AP). The HPLC conditions were as follows: column, Cosmosil 5C18 (4.6 mm i.d. x 250 mm); mobile phase, 10 mM imidazole-perchloric acid buffer(pH 7.6)-acetonitrile (1:1, v/v); CL reagent, 0.02 mM bis(2,4,6-trichlorophenyl)oxalate (TCPO) and 15 mM hydrogen peroxide in acetonitrile. The oxidative degradation of DAPs and AP in the presence of metals was prevented by adding ascorbic acid to sample solutions. The calibration curves were straight over 2 orders of magnitude for all analytes, and their detection limits (as S/N was 3) were in the sub-fmol range. Dinitro- and nitropyrenes in sooty emissions of diesel- and gasoline-engine cars could be determined by this HPLC after reductive conversion into DAPs and AP, respectively, by refluxing the samples in the presence of sodium hydrosulfide.