Spectrophotometric determination of Hg(II) in water samples by dispersive liquid liquid microextraction with use ionic liquid after derivatization with a water soluble Fe(II) phthalocyanine

This study reports the synthesis of water soluble iron(II) phthalocyanine and a facile method for spectrophotometric determination of Hg(II) in environmental water samples by ionic liquid based dispersive liquid-liquid microextraction (IL-DLLME). In the method, 1-heptyl-3-methylimidazolium hexafluorophosphate (250 A mu L) as extraction solvent, acetonitrile (750 A mu L) as dispersive solvent and Triton X-100 (200 A mu L) as anti-sticking agent were used. After the extraction of the Hg(II) complex (Hg(II):q-Fe(II)-Pc) into thin droplets of ionic liquid, the sample was centrifuged for 4 min at 2000 rpm. The upper aqueous phase was removed and the residue diluted to 250 A mu L with methanol and transferred to a 250 A mu L cell for spectrophotometric detection at 280 nm. The linear range of the method is 0.05-1 A mu g/mL. The limits of detection and quantification is 0.01 and 0.03 A mu g/mL, respectively. The RSD for the developed method was calculated as 0.78% at 0.50 A mu g/mL Hg(II).