Determination of Aromatic Amines in Soils

Abstract

A rapid liquid chromatographic (LC) method with ultraviolet (UV) or fluorescence detection was developed for parts-per-billion levels of aromatic amines in soils. 2,4-Diaminotoluene, pyridine, aniline, 2-picoline, 2-toluidine, 5-nitro-2-toluidine, 2-methyl-6-ethylaniline, 4-aminobiphenyl, 4-nitroaniline, 1-naphthylamine, 2-methoxyaniline, and 2-naphthylamine were tested. The method involves extraction by sonication with 1% ammonium hydroxide-acetonitrile and analysis by LC using gradient elution with aqueous 0.01M ammonium acetate-0.0005% triethylamine and acetonitrile. Recoveries of 67-106% (9.2 and 34% for 1- and 2-naphthylamines, respectively) were obtained from sand and organic-containing soils spiked in the parts-per-million range. Recoveries from sand spiked at 8.5-25 ppb were 88-105%. Recoveries from organic soil varied from nondetectable to 86% at spikes of 85-500 ppb. Detection limits ranged from 0.5 ppb for highly fluorescent 2-naphthylamine (by fluorescence detection) to 0.5 ppm for nonfluorescing pyridines (by UV detection).