Simultaneous Pre-Concentration of Cadmium and Lead in Environmental Water Samples with Dispersive Liquid-Liquid Microextraction and Determination by Inductively Coupled Plasma-Atomic Emission Spectrometry

Abstract

The dispersive liquid–liquid microextraction (DLLME) method for determination of Pb+2 and Cd+2ions in the environmental water samples was combined with inductively coupled plasma-atomic emissionspectrometry (ICP-AES). Ammonium pyrrolidine dithiocarbamate (APDC), chloroform and ethanol were usedas chelating agent, extraction solvent and disperser solvent, respectively. Some effective parameters on themicroextraction and the complex formation were selected and optimized. These parameters included extractionand disperser solvent type as well as their volume, extraction time, salt effect, pH, sample volume and amountof the chelating agent. Under the optimum conditions, the enrichment factor of 75 and 105 for Cd+2 and Pb+2ions respectively was obtained from only 5.00mL of water sample. The detection limit (S/N=3) was 12 and0.8ngmL−1 for Pb and Cd respectively. The relative standard deviation (RSDs) for five replicate measurementsof 0.50 mgL−1 of lead and cadmium was 6.5 and 4.4 % respectively. Mineral, tap, river, sea, dam and spikedwater samples were analyzed for Cd and Pb amount.