A magnetic effervescent-assisted ionic liquid-based dispersive liquid-liquid microextraction technique for the simultaneous determination of five typical drugs in biological real samples by gas chromatography-selected ion monitoring-mass spectrometry using chemometrics methodology

Many drugs currently consumed were, in the past, not only marketed freely, but also promoted as beneficial substances by the pharmaceutical industry [1]. The disordered consumption of pharmaceuticals, led to the increase of legal restrictions and the raise of illicit trade of these substances [2]. In order to control drug crime effectively, it is necessary to develop selective and sensitive analytical methods suitable for unambiguous identification and determination of drugs in illicit samples and biological matrices [3]. In this study a novel, fast and green analytical method (called magnetic effervescent-assisted ionic liquid-based dispersive liquid-liquid microextraction (ME-IL-DLLME)) followed by gas chromatography-selected ion monitoring-mass spectrometry (GC-SIM-MS) has been proposed for the extraction and simultaneous determination of five typical drugs (ibuprofen, fluoxetine, phenobarbital, naproxen and diclofenac) in human urine and hair samples. This method combines ionic liquid-based dispersive liquid-liquid microextraction with the magnetic retrieval of the extractant. A magnetic effervescent tablet composed of NiCo magnetic nanoparticles [4], tartaric acid, citric acid, sodium bicarbonate and 1-butyl- 3-methy-limidazolium hexa fluoro phosphate was used for extractant dispersion and retrieval. Magnetic effervescent tablet was placed in the sample solution and a large quantity of bubbles formed and rose from the bottom due to the effervescence reaction. By disintegrating the effervescent tablet, the extraction solvent (ionic liquid) was homogeneously distributed into the aqueous sample. The main factors affecting the extraction efficiency were screened by a D-optimal mixture design and optimized by a Box-Behnken design [5]. Under the optimum conditions, good linearity (0.991-0.997) was obtained for all analytes in urine and hair samples and the method showed low limits of detection between 0.03 and 0.08 ng mL-1. Extraction recoveries and enrichment factors were from 86% to 91% and 3250 to 3720. The intra-day and inter-day precision both were lower than 4.2%.