Single drop microextraction in a 96-well plate format: A step toward automated and high-throughput analysis

Abstract

In this study, an innovative and high-throughput parallel-single-drop microextraction (Pa-SDME) using the [P6,6,6,14+]2[MnCl42−] magnetic ionic liquid (MIL) as extraction phase is demonstrated, for the first time, in the determination of methylparaben, ethylparaben, propylparaben, bisphenol A, butylparaben, benzophenone and triclocarban from environmental aqueous samples. This experimental setup comprised of a 96-well plate system containing a set of magnetic pins which aided in stabilizing the MIL drops and enabled the simultaneous extraction of up to 96 samples. Using this low-cost experimental apparatus, the sample throughput was lower than 1 min per sample. This novel approach exhibits a number of advantages over classical SDME approaches, particularly in maintaining a stable solvent microdrop and facilitating highthroughput analysis. Experimental conditions were carefully optimized using one-factor-at-a-time and multivariate designs. The optimal conditions employed 5.38 ± 0.55 mg (n = 10) of MIL, a sample volume of 1.5 mL at pH 6, and dilution in 20 μL of acetonitrile. The analytical parameters of merit were determined under the optimized conditions and highly satisfactory results were achieved, with LODs ranging from 1.5 to 3 μg L−1 and coefficients of determination higher than 0.994. Intraday and interday precision ranged from 0.6 to 21.3% (n = 3) and 10.4-20.2% (n = 9), respectively, with analyte relative recovery in three aqueous samples ranging between 63% and 126%.

High‐throughput microscale extraction using ionic liquids and derivatives: A review

“…Among the different MIL‐SDME applications, the work developed by Mafra et al. for the determination of a group of contaminants of emerging concern including parabens, bisphenol A, benzophenone, and triclocarban [17] is worth mentioning. The high‐throughput procedure, so‐called parallel‐DI‐SDME, was based on the use of a 96‐well plate and a blade with a set of rod magnets glued onto the blade pins, as shown in Figure 4 [17].…”

“…In accordance with the current trends in analytical chemistry and green analytical methodologies [15], novel strategies are gradually being incorporated in IL‐based microscale extraction approaches for the additional increase of the sample throughput while ensuring the performance of the analytical process in an unsupervised mode. These strategies utilize different tools, such as tailor‐made extraction devices and parallel extraction [16,17] or magnetic separation [18]. Other alternatives employ flow injection (FI) approaches [19], robotic equipment [20], or microfluidics [21] for the development of semi‐automatic or even fully automatic/automated methodologies [22].…”

Alternative Green Extraction Phases Applied to Microextraction Techniques for Organic Compound Determination

“…The proposed methodology achieved higher extraction efficiency when compared to the conventional MIL-dispersive liquid-liquid microextraction. Extraction efficiencies ranging from 46 [45].…”

“…MILs have also been successfully applied to the SDME technique. In a recent study, a high-throughput parallel-single-drop microextraction (Pa-SDME) was developed [46]. According to the authors, Pa-SDME combines some advantageous features of trihexyl (tetradecyl) phosphonium tetrachloro manganite (II) ([P6, 6, 6, 14 + ] 2 [MnCl 4 2− ]) MIL such as drop stability and extraction capacity with the 96-well plate advantages for obtaining high-throughput analysis.…”

“…An overview of the extraction procedure using the novel parallel-single-drop microextraction (Pa-SDME)/MIL-based approach. Reproduced with permission from [46], Copyright Elsevier, 2017.…”