Ultra-Trace Determination of Lead(II) in Water Using Electrothermal Atomic Absorption Spectrometry after Preconcentration by Solid-Phase Extraction to a Small Piece of Cellulose Acetate Type Membrane Filter

A simple and inexpensive preconcentration technique has been developed for the ultra-trace determination of lead(II) using electrothermal atomic absorption spectrometry (ETAAS). The lead(II) complex with dicyclohexano-18-crown 6-ether (DC18C6) was extracted to a small piece of cellulose acetate-type membrane filter (2 x 5 mm) merely by vigorously eccentric stirring for 120 min under the coexistence of sodium dodecyl sulfate (SDS) at around pH 7. The extraction medium was inserted into a graphite cuvette for the determination of lead(II) by ETAAS. A linear relation was obtained for the range of 0.1 - 5.0 ng in 10 ml of lead(II) standard solution (r = 0.998). The detection limit was found to be 0.03 ng of lead(II) in 10 nil (0.003 mu g l(-1)) of water sample. The proposed method was applied to the ultra-trace determination of lead(II) in river water, underground water, tap water, and snow fall samples.