Trace Determination of Cadmium Ions by Flame Atomic Absorption Spectrometry after Pre-Concentration Using Temperature-Controlled Ionic Liquid Dispersive-Liquid Phase Microextraction

Abstract

This paper is about an improved temperature-controlled ionic liquid dispersive liquid-phase microextraction method for pre-concentration of cadmium ions prior to determination by flame atomic absorption spectrometry. In this study, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) was used as extraction solvent. Cadmium complexed with dithizone, and then entered into the dispersed ionic liquid droplets at 40 oC. Some parameters affecting the extraction efficiency such as the volume of [C4MIM][PF6], dissolving temperature, sample pH, centrifuging time and salt effect have been investigated in detail. The calibration graph was linear in the range of 2-250 ng mL-1, the limit of detection (3Sb) was 0.62 ng mL-1. The enhancement factor was found to be 48.4 and the relative standard deviation (RSD) for 10 replicate determinations of 50 ng mL-1 Cd was 2.7%. The developed method successfully applied to the determination of cadmium in several real samples.