Effect of potassium iodide on reducing the adsorptive interference of surfactants and organics in the determination of lead and cadmium in environmental samples by differential-pulse anodic stripping voltammetry

Abstract

The complexing and adsorbing properties of potassium iodide were investigated for anodic stripping voltammetric measurements of Pb and Cd in the presence of organics and surfactants. Up to 100 ppm of pectic acid, agar and gelatin do not affect the voltammetric response of either Pb or Cd. Up to 100 ppm of dodecylamine (DDCA), alginic acid, 40 ppm of camphor and 6 ppm of humic acid do not affect the voltammetric response of Cd (8 ppb). Up to 100 ppm of camphor, 50 ppm of alginic acid, 20 ppm of humic acid and 10 ppm of Triton X-100 and DDCA do not affect the voltammetric response of Pb (20 ppb). The effect of sodium dodecyl sulfate on Cd can be eliminated completely by DDCA but that on Pb only partly. The sensitivity of the determination increased by 50% and 100% for Pb and Cd, respectively. The behaviour of Pb and Cd with organics was studied in the presence of KI. Pb and Cd were determined in different fractions of dust samples and synthetic waste water.