Keywords: spectrophotometry, potassium hexacyanoferrate(II), 2-methylpyrazine, ligand substitution, mercury (II), catalytic kinetics, water pollution, environmental pollution, heavy metals
Determination of trace amounts of mercury (II) by catalytic kinetic method in environmental samples
A highly selective and sensitive, spectrophotometric method is developed for the determination of Mercury(II) in environmental waters samples, based on indicator reaction of potassium hexacyanoferrate(II) and 2-methylpyrazine (2-Mepz), catalysed by Hg(II). The reaction was monitored spectrophotometrically at pH = 3.50 ± 0.02 and 25.0 ± 0.1°C by measuring the change in absorbance over time at 447 nm (λmax = 447 nm) for 20 min. Mercury can be determined within the range 20.06-200.6 ng mL−1 with relative standard deviation of sr = 3.02 at 20.06 ng/mL Hg(II) level. Interference due to many cations and anions was also studied at 200.6 ng/mL level.