Complexometric determination of mercury(II) with 2-imidazolidinethione as a selective masking agent.
A simple, rapid and selective complexometric method is proposed for the determination of mercury(II). Mercury(II) is first complexed with a known excess of EDTA and the surplus EDTA is back-titrated at pH 5.0-6.0 with lead nitrate, Xylenol Orange being used as indicator. 2-Imidazolidinethione is then added to displace EDTA from the Hg-EDTA complex quantitatively and the EDTA released is titrated with lead nitrate. Reproducible and accurate results are obtained for 2-75 mg of mercury, with a relative error of less than 0.3% and standard deviation of less than 0.04 mg.
Narayana
B
B
Department of Post-Graduate Studies and Research in Chemistry, Mangalore University, Mangalagangothri 574 199, Karnataka, India.
Gajendragad
M R
MR