Electrochemiluminescence determination of nitro polycyclic-aromatic hydrocarbons using HPLC separation

Abstract

In order to analyse nitro-polycyclic aromatic hydrocarbons (NPAHs), the NPAHs were reduced to amino-polycyclic aromatic hydrocarbons (APAHs), separated by HPLC and monitored with electrochemiluminescence detection (ECL). Based on a post-column reaction with bis(2,4,6-trichlorophenyl) oxalate, the ECL observations of APAHs were performed in hydrogen peroxide solution, which was electrogenerated from an electrolysis flow cell equipped with a reticulated vitreous carbon working electrode at the potential of -1.5 V (vs. Ag/AgCl). The potential of the working electrode was controlled by a potentiostatic electrolytic system. The ECL behavior of ten NPAHs has been studied, showing that the ECL intensities are affected by the number of conjugated benzene rings. Reagent solution containing 0.3 mmol L-1 bis(2,4,6-trichlorophenyl) oxalate in acetonitrile with a flow rate of 0.4 mL min(-1) and a carrier solution of 0.05 mol L-1 imidazole: acetonitrile buffer solution (pH = 6.5, 60:40) with a flow rate of 1.0 mL min(-1) were used. The detection limits of NPAHs ranged from 1.0 x 10(-9) mol L-1 to 8.0 x 10(-5) mol L-1. An analytical system based on the HPLC-ECL principle was developed for the analysis of NPAHs in extracts of diesel and gasoline engine exhaust particulates with minimal sample preparation.