Colorimetric determination of mercury with Methylthymolblue
1963 Volume 12 Issue 12 Pages 1183-1188
Details
1963 Volume 12 Issue 12 Pages 1183-1188
A colorimetric determination of mercury (II) in aqueous solution using Hg (II) complex with Methylthymolblue (MTB) was presented. The characteristics of the complex at pH 6.0 were as follows : the constitution Hg : MTB=1 : 1, the apparent formation constant log K = 5.5, the maximum absorption wavelength λmax=630 mμ, and the molar absorption coefficient at 630 mμ, ε=1.01×104.
The proposed method for the determination was as follows : the sample solution containing 0.0250.750 mg Hg(II) is mixed with 5.0 ml of 10-4M MTB solution and 1 ml of hexamine-HNO3 buffer solution (pH 6.0), made up to 25 ml with water, and the absorbance of the mixed solution at 630 mμ is measured within 1030 minutes against the reagent blank in a 1 cm cell. The method was simple and accurate. Cu(II), Zn (II), Pb (II), Fe (III), Cl and citrate interfered, and the suppretion of their interferences was discussed.
