Ionic liquid dispersive liquid–liquid microextraction of lead as pyrrolidinedithiocarbamate chelate prior to its flame atomic absorption spectrometric determination

A novel separation–preconcentration procedure based on ionic liquid dispersive liquid–liquid microextraction of traces lead as pyrrolidinedithiocarbamate chelate has been developed. 1-Hexyl-3-methylimidazolium hexafluorophosphate as ionic liquid was used for extraction of lead pyrrolidinedithiocarbamate chelate. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry (FAAS). The effects of pH, amounts of ligand, amounts of 1-hexyl-3-methylimidazolium hexafluorophosphate, sample volume etc. on the recoveries of lead ions were investigated. The influences of some cations and anions on the recoveries of lead were also examined. The preconcentration factor was calculated as 40 at the sample volume of 20 ml. The detection limit for lead ions was 1.5 μg/l. The validation of the presented method was performed by the analysis of TMDA-51.3 fortified water. The method was applied to natural water samples.

Research highlights
► Separation–preconcentration procedure based on ionic liquid dispersive liquid–liquid microextraction of traces lead as pyrrolidinedithiocarbamate chelate.
► Determination by flame atomic absorption spectrometry.
► Application to natural water samples.