Ultrasound-assisted ionic liquid-based microextraction combined with least squares support vector machines regression for the simultaneous determination of aluminum, gallium, and indium in water and coal samples

Abstract

A new simple and rapid ultrasound-assisted ionic liquid-based microextraction method was applied to preconcentrate aluminum(III), gallium(III), and indium(III) ions from water samples as a prior step to their simultaneous spectrophotometric determination using least squares support vector machines regression. In the novel procedure, 1-hexyl-3-methylimidazolium hexafluorophosphate [C 6 MIM][PF 6 ] was dispersed into the aqueous sample solution as fine droplets by ultrasonication, and the analytes were extracted into the ionic liquid phase after complexation with 1,2,5,8-tetrahydroxy anthraquinone (quinalizarine). After centrifuging, the fine droplets of extractant phase were settled to the bottom of the conical-bottom glass centrifuge tube. The detection limits for Al(III), Ga (III), and In(III) were 1.70, 2.02, and 2.06 ng mL −1 , respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of ten replicates, was below 3.2% for all elements. The method was successfully applied for the determination of Al(III), Ga(III), and In(III) in real samples.

Determination of Heavy Metal Ions and Organic Pollutants in Water Samples Using Ionic Liquids and Ionic Liquid-Modified Sorbents

“…In this case, the three metal ions should be removed from water samples. Ghasemi and Zolfonoun [68] used UA-ILDME to detect Al 3+ , Ga 3+ , and In 3+ in water samples (tap water, mineral water, and well water), and [HMIM][PF 6 ] was selected with 1,2,5,8-tetrahydroxy anthraquinone (quinalizarine) as an ion-pairing agent. The relative recoveries for the spiked samples were in the range of 86.0–120.0%.…”

Ionic liquid-based microextraction techniques for trace-element analysis

“…This work is another example of how chemometrics, specifically numerical analytical methods, such as LS-SVM, can be used to solve linear and non-linear multivariate calibration problems in a relatively fast way, so allowing simultaneous elemental determination without previous separation. The LODs for Al(III), Ga(III), and In(III) were 1.70 ng mL −1 , 2.02 ng mL −1 and 2.06 ng mL −1 , respectively, with RSDs below 3.2% for most of these elements [155]. Trace amounts of Rh(III) were determined in a platinum-iridium alloy with a 95% recovery.…”

First evidence of metal transfer into hydrophobic deep eutectic and low-transition-temperature mixtures: indium extraction from hydrochloric and oxalic acids

“…4 There are several publications devoted to indium extraction by means of ionic liquids. [5][6][7][8][9] The only fluorine-free report of indium extraction is a new tetraoctylphosphonium oleate ionic liquid, which consists of a alkylphosphonium cation and an oleic acid anion. 10 However, metal extraction was reported only in a narrow range of low acidities.…”