An Analytical Method to Determine Selected Nitro-PAHs in Soil Samples by HPLC With Fluorescence Detection

A simple analytical procedure was optimized for the analysis of selected nitro polycyclic aromatic hydrocarbons in soil samples. The procedure involved the sonication of analytes with dichloromethane and derivatization through sodium borohydride reduction. 3-Nitrophenanthrene, 9-Nitrophenanthrene, 1-Nitropyrene, and 3-Nitrofluoranthene were selected based on toxicity, abundance, and reference material availability. Analytical determinations were carried out by high-performance liquid chromatography with fluorescence detection, applying 254/410, 254/444, 244/438, and 244/528 nm for 3-Nitrophenanthrene, 9-Nitrophenanthrene, 1-Nitropyrene, and 3-Nitrofluoranthene detection, respectively. Quantification limits obtained for all of these compounds were between 16 and 60 ng kg⁻¹ dry mass. Overall recoveries ranged from 89–106% at three fortification levels, and no significant bias was detected. Robustness of the method was demonstrated. Analyses over time were carried out for three types of soil samples and intermediate precision was estimated between 16 and 32%.