Abstract
A simple and low cost method was developed and validated for the determination of trace mercury (II) ions in dental-unit wastewater and fertilizer samples. The method was based upon the reaction of mercury (II) ions with the novel reagent 6-hydroxy-3-(2-oxoindolin-3-ylideneamino)-2-thioxo-2H-1,3-thiazin-4(3H)-one, the formed complex shows an absorption maximum at 505
nm (
λ
max) in Britton–Robinson (B–R) buffer (pH 4–6).The corrected absorbance of the formed complex at
λ
max was obtained employing
β-correction spectrophotometric method. Beer's–Lambert law and Ringbom's plots of the colored Hg–reagent complex were obeyed in the concentration range of 0.2–2.0 and 0.32–0.96
μg
mL
−1 mercury (II) ions, respectively with a relative standard deviation in the range of 2.1±1.3%. The limits of detection (LOD) and quantification (LOQ) of the procedure were 0.026 and 0.086
μg
mL
−1 Hg
2+, respectively. The proposed method was applied for the analysis of mercury (II) in dental-unit wastewater and fertilizer samples. The validation of the method was tested by comparison with the data obtained by the inductively coupled plasma-mass spectrometry (ICP-MS). The statistical treatment of data in terms of Student's
t-tests and variance ratio
f-tests has revealed no significance differences.