A simple, sensitive and selective solid phase reflectometry method is proposed for the determination of
trace mercury in aqueous samples. The complexation reagent dithizone was firstly injected into the properly
buffered solution with vigorous stirring, which started a simultaneous formation of nanoparticles
suspension of dithizone and its complexation reaction with the mercury(II) ions to make Hg–dithizone
nanoparticles. After a definite time, the mixture was filtered with membrane, and then quantified directly
on the surface of the membrane by using integrating sphere accessory of the UV–visible spectrophotometer.
The quantitative analysis was carried out at a wavelength of 485 nm since it yielded the largest
difference in diffuse reflectance spectra before and after reaction with mercury(II).A good linear correlation
in the range of 0.2–4.0 g/L with a squared correlation coefficient (R2) of 0.9944 and a detection
limit of 0.12 g/L were obtained. The accuracy of the method was evaluated by the analysis of spiked
mercury(II) concentrations determined using this method along with those determined by the atomic fluorescence
mercury vapourmeter and the results obtained were in good agreement. The proposed method
was applied to the determination of mercury in tap water and river water samples with the recovery in
an acceptable range (95.7–105.3%).