First-Order Derivative Spectrophotometry Method with Triapine as Chelating Agent for Simultaneous Determination of Barium(II) and Lead(II)

Abstract

A simple, selective and sensitive first-order spectrophotometric method was used for the simultaneous determination of Ba(II) and Pb(II) with triapine as chelating agent. When triapine reagent was mixed with Ba(II) and Pb(II) solutions, it produces a light green colour in a basic medium. Maximum peaks for both Ba(II) and Pb(II) were observed at pH 8.5 (basic buffer solution) between 350 and 395 nm. Ba(II)-triapine has a molar absorbance of 5.276 × 106 L mol-1 cm-1 and a Sandell’s sensitivity of 0.000189 g/cm2. Similarly, they are 9.421 × 105 L mol-1 cm-1 and 0.00106 g/cm2 for Pb(II)-triapine, respectively. The stability constants of Ba(II)-triapine and Pb(II)-trapine complexes are 3.207 × 104 and 5.118 × 104, respectively. The effects of Ba(II)-triapine and Pb(II)-triapine concentrations on amplitude were also studied. The detection and quantification limits for Ba(II)-triapine are 0.0882 g/mL and 0.746 g/mL, respectively. Similarly, detection and quantification values were 0.089 g/mL and 0.745 g/mL for Pb(II)-triapine, respectively. The developed or proposed method was used to examine biological samples of carrots, onions, beans, paints, milk powder and alloys. The sample results were close to the certified reference values for the ICP-AES, FDA and AAS methods.