Ionic Liquid-based Ultrasound-assisted In-situ Solvent Formation Microextraction and High-performance Liquid Chromatography for the Trace Determination of Polycyclic Aromatic Hydrocarbons in Environmental Water Samples

Abstract

A green and efficient ionic liquid-based ultrasound-assisted in-situ solvent formation<br />microextraction (IL-UA-ISFME) in combination with high-performance liquid chromatographyultraviolet<br />detection (HPLC-UV) has been successfully developed for the trace determination of<br />five selected polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. In this<br />method, a hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) was<br />formed by addition of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) to<br />sample solution containing an ion-pairing agent (NaPF6). The analytes were extracted into the ionic<br />liquid phase while the microextraction solvent was dispersed through the sample by utilizing<br />ultrasonic radiation. The sample was then centrifuged and extracting phase retracted into the<br />microsyringe, diluted with acetonitrile, and injected to HPLC. In the beginning, effective<br />parameters controlling the performance of the microextraction process were studied in detail and<br />optimized. The limit of detections (LOD, S/N = 3) were in the range of 0.32-0.79 μg L-1 while the<br />RSD% values were below than 5.2% (n = 6). A good linearity (0.997 ≥ r2 ≥ 0.992) and a broad<br />linear over the concentration ranges from 1 to 500 μg L-1 were achieved. The method was<br />ultimately applied for the preconcentration and sensitive determination of the PAHs in several<br />environmental water samples. The accuracy of the method in the real samples was tested by the relative recovery experiments with results ranging from 90-106%, which confirmed that<br />complicated matrixes had almost little effect on the developed analytical procedure.<br /><br />