An easy and green amine-based microextraction strategy combined UV–Vis spectrophotometric detection for mercury in natural water samples

An amine-based microextraction method was established for preconcentration of mercury by forming a 1-(2-pyridylazo)-2-naphthol (PAN) chelate complex. The Hg (II)-PAN hydrophobic complex was extracted into the N,N-dimethyl-n-octylamine phase at pH 9.5, after the pre-concentration of Hg (II), the absorption spectrum was taken with UV–Vis spectrophotometer at 555.0 nm. The effects of important analytical parameters such as pH, PAN amount, N,N-dimethyl-n-octylamine volume, sample volume and matrix effects for quantitative recovery were investigated and optimized. 0.05% (w/v) PAN volume, N,N-dimethyl-n-octylamine volume, vortex time and centrifugation time were optimized as 0.4 mL, 0.1 mL, 1 min and 15 min, respectively. The validity of the developed liquid phase micro-extraction method was checked by standard addition-recovery experiments. The presented microextraction method was successfully applied for mercury determination in natural water samples. The mercury concentration in natural water samples ranged from 0.20 to 1.42 µg mL-1. The limit of detection (LOD), limit of quantification (LOQ) and preconcentration factor (PF) were found as 0.035 μg L−1, 0.12 μg L−1 and 26.67, respectively.