Tuesday, October 1, 2019
Department of Chemistry
Mississippi State University
HL 1144 - 4:00 pm
Tuesday, October 1, 2019
To date, extensive studies on sample pre-treatment techniques are done using different solvents and sorbents as there is a persistent need for green, efficient, and cost effective methods. Microextraction techniques have attracted much interest recently as a solution for tedious procedures with huge consumption of toxic organic solvents also they are considered as green alternatives for the conventional liquid-liquid extraction (LLE) and solid-phase extraction (SPE). Microextraction techniques are solvent free or consume microliter volume of solvents. Therefore, this causes to minimize the consumption of toxic volatile organic solvents and reduction of the waste production which satisfy the key aspects of green chemistry. Of the several techniques available for the solvent-based microextraction, dispersive liquid–liquid microextraction (DLLME) has been developed and improved within the last decade as it is simple, inexpensive, environmental friendly, and could offer high enrichment factors and extraction efficiencies compared to other solvent- or even sorbent-based microextraction methods. DLLME is a three component system. Rapid mixing of the analyte-containing aqueous sample with an organic solvent, which is immiscible with water, with the aid of a dispersive solvent which is miscible in both aqueous and the organic solvent forms fine droplets where the partition of the analyte takes place between two immiscible phases. Analytes tend to enrich in the low volume of extracting solvent, which is dispersed in the aqueous solution, and usually separated by centrifugation. During past few years, DLLME method has undergone to several improvements and modifications. Utilization of ionic liquids in DLLME (IL-DLLME) as an extracting solvent has become popular as they possess unequivocally a “green” character and tuneable physicochemical properties. With improvements and modifications to the conventional DLLME methods, IL-DLLME methods have been successfully applied for the extraction and determination of a wide spectrum of organic and inorganic analytes from a variety of samples such as environmental, water, food, cosmetic, and biological etc.
In this seminar, conventional sample preparation techniques, microextraction techniques and conventional DLLME method will be briefly introduced. Then the recent advances in DLLME method using ILs will be discussed in details.
1Figure taken from Pavón,P.,et al, Anal. Chim. Acta. 2008, 629, 6-23.
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