Differential pulse polarographic determination of lead in standard alloys and biological samples after separation and preconcentration with PAN.
A highly selective, sensitive, rapid and economical differential pulse polarographic method has been developed for the determination of trace amount of lead in various samples after adsorption of its 1-(2-pyridylazo)-2-naphthol (PAN) on naphthalene in the pH range of 8.4 - 11.5. After filtration, the solid mass is shaken with 9.0 ml of 1 M hydrochloric acid and lead is determined by differential pulse polarography (DPP). Lead can alternatively be quantitatively adsorbed on [1-(2-pyridylazo)-2-naphthol]-naphthalene adsorbent packed in a column and determined similarly. The detection limit is 0.1 microg/ml (signal to noise ratio = 2) and the linearity is maintained in the concentration range 0.3 - 300 microg/ml with a correlation coefficient of 0.9996 and relative standard deviation of +/- 1.1%. Characterization of the electroactive process included an examination of the degree of reversibility. Various parameters such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of lead has been studied in detail to optimize the conditions for determination in alloys and biological samples.
Department of Chemistry, Shahid Bahonar University of Kerman, Kerman, Iran. ma_taher@yahoo.com
Mohammad Ali
MA
Taher
D000497:Alloys / Q000737:chemistry; D004785:Environmental Pollutants / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D007854:Lead / Q000032:analysis*; D009284:Naphthols / Q000737:chemistry*; D012680:Sensitivity and Specificity
D000497:Alloys; D004785:Environmental Pollutants; D009284:Naphthols; C041728:1-(2-pyridylazo)-2-naphthol; D007854:Lead