VALIDATED DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS DETERMINATION OF Pd AND Hg USING 6-(2-NAPHTHYL)-1,2,4-TRIAZINE-3-THIONE

A simple and sensitive derivative spectrophotometric method based on the zero-crossing technique using 6-(2-naphthyl)-2,3-dihydro-1,2,4-triazine-3-thione(NDTT) for simultaneous determination of Hg(II) and Pd(II) was developed. The reagent, NDTT, reacts with mercury and palladium ions to form stable yellow and yellowish green complexes in basic media which is easily extractable with chloroform.

The second order derivative absorbance with Dλ = 31.5 at 375.5 nm and 309.0 nm were selected for the determination of Hg(II) and Pd(II), respectively. The absorbance of the complex obeys Beer’s law in the concentration range of 5-50 μg/mL and 2-35 μg/mL with r= 0.9982 and 0.9946 for Hg and Pd, respectively.

The within-day and between-day variations showed coefficient of variation (%CV) values not more than 2.8% and 3.46% for Hg and Pd respectively. The error of determination was less than 2.40%.

The proposed method was suitably applied to a synthetic and a tea sample successfully and the results were compared with atomic absorption method. The results showed that there was no significant difference between two methods.