Reagents used:
1) Air: Cleaned and dried through a filter air;
2) Acetylene: Standard, commercial graded;
3) Metal free water: All the reagents and dilutions were made in metal free water;
4) Methyl isobutyl ketone (MIBK): Reagent grade MIBK is purified by redistillation before use;
5) Ammonium pyrrolidine dithiocarbonate (APDC) solution: 4 gm APDC is dissolved in 100 ml water;
6) Conc. HNO3;
7) Standard metal solutions: Five standard solutions of 0.01, 0.1, 1, 10 and 100 mg/l concentrations of metals for instrument calibration and sorption study are prepared by diluting their stock solution of 1 gm/l i.e. 1 ml = 1 mg metal.