Multisyringe flow injection analysis for determination of 1-naphthylamine in water samples

Abstract

1-Naphthylamine (NPA) is one of the main degradation products of pesticides derived from naphthalene, and a well-known bladder carcinogen in men. The Griess assay is used for NPA determination because of its high sensitivity and selectivity. The azo dye 4-(sulphophenylazo)-1-naphthylamine is formed, which shows a peak maximum at 540nm. After optimizing multisyringe flow injection analysis (MSFIA) parameters, the analytical characteristics of the method were obtained, with a working linear range of 0.5 to 14mg L-1, according to the equation A = 0.0738 +/- 0.0019 {[}NPA] + 0.0028 +/- 0.0042, r = 0.9997. Values for RSD (\%) and E-rel (\%) were calculated for the concentration levels of 0.5, 6 and 12mg L-1; values obtained were 1.1, 0.4 and 0.3\% for RSD and 0.8, 0.3 and 0.2\% for E-rel, respectively. LD was 0.01mg L-1 and LQ was 0.04mg L-1 NPA. The MSFIA procedure for the determination of NPA was applied to different water samples (well water, tap water, seawater, and wastewater from the EDAR-1, Palma de Mallorca water treatment plant), with satisfactory results and a throughput of 90 samples per hour.