Application of an In-situ Solvent Formation Microextraction Technique Using the Functionalized Ionic Liquids (FILs) as a Green Extractant for Cadmium Determination at Trace Levels in Real and Saline Samples

Abstract

An in-situ solvent formation microextraction technique as another attractive mode of homogeneous liquid-liquid microextraction, was developed successfully for the sensitive extraction of cadmium ion. In this technique use green extracting solvent such as ionic liquids that are environment lover. So, because using ionic liquids, this technique is much safer than other extraction methods which use toxic common organic solvents. Functionalized ionic liquid of 3-(2-(bis(2-(tert-butoxy)-2-oxoethyl)amino)ethyl)-1-methylimidazolium bromide was used as extractant and organic phase which has double role including complexing agent and extractant, so to extraction of cadmium ion, not need to any complexing agent. To optimization of extraction conditions, several analytical parameters affected on microextraction efficiency including sample pH, functionalized ionic liquid dosage, counter-ion amount and centrifugation conditions were studied. To show abilities of the method, the figures of merits including limit of detection and quantification, relative standard deviation, linear dynamic range and enrichment factor were calculated and included 0.23 µg/L, 0.76 µg/L, 1.8%, 10-1500 µg/L and 75, respectively. It was found from results that the method was applied successfully for the determination of Cd (II) ion in several real, and saline samples. Because of use environmental solvents such as ionic liquids, and very small dosage of its, it can be said the method has low toxicity and classified as a green extraction/preconcentration technique. One the other hand, the presented method opens a new window in the analytical applications due to its costless, ease in experimental setup and use of non toxic solvents as an extractant.