Rapid extraction and separation of mercury in water and food samples based on micelles and azo-thiazoles complexation before determination by UV-Vis spectrophotometry

Abstract

A simple and sensitive procedure has been established for analyzing mercury (II) ions spectrophotometrically in the presence of micellar medium using three azo-thiazoles complexing reagents: 2-amino-6-(thiazole-2-yldiazenyl)-3-pyridinol (C8H7N5OS), 8-hydroxy-7-(thiazole-2-yldiazenyl) quinoline-5-sulfonic acid (C12H8N4O4S2), and 1-hydroxy-4-(thiazole-2-yldiazenyl)-2-naphthoic acid (C14H9N3O3S). H1 NMR spectra validated the three azo thiazoles synthesized material. Tween 80 (polysorbate 80) and cetyltrimethylammonium bromide (C19H42BrN as molecular biology) are micellar mediums to enhance sensitivity. Absorbances were measured for Hg (II) complexation with R1, R2, and R3 at λmax of 617, 633, and 554 nm, respectively. The UV-Vis spectrophotometer showed calibration curves in the 0.2-15 mg L-1. The molar absorptivity, Sandell's sensitivity, detection, and quantification limits (LOD, LOQ) were determined. The interferences of various ions were investigated, and a statistical assessment of the results was performed. The methods have been applied for trace determination of mercury (II) in food and environmental water samples. For food samples, all samples were digested before complexation with the azo-thiazoles material at optimized pH before determination by UV-Vis spectrophotometry.