A simple andefficient hollow fiber-based method,viz magnetic solvent bar liquid-phasemicroextraction (MSB-LPME) combined with gas chromatography-flame ionization detection (GCFID)has been successfully developed for the trace determination of mononitrotoluenes (MNTs) innatural water samples. The analytes were extracted from sample solution to the organic solventimmobilized in a fiber. Following the extraction, the analyte-adsorbed magnetic solvent bar can beeasily isolated from the sample solution by a magnet which could significantlyfacilitate theoperation as well asreducing the total pretreatment time. The bar was mainly eluted withacetonitrile, evaporated to dryness while the residue was dissolved in toluene and finally injectedinto GC-FID. At first, a series of parameters influencing microextraction performance weresystematically investigated and optimized. The values of the detection limit were in the range of0.05-0.08 μg L-1 and the RSD% for the analysis of 50.0μg L-1 of the analytes was below than 5.8%(n = 6). An acceptable linearity (0.996 ≥ r2 ≥ 0.995) and a broad linear range (0.2-200 μg L-1) wereachieved. The method was eventually employed for the preconcentration and determination of theMNTs in environmental water samples and acceptable results were reached. Manuscript profile

A green and efficient ionic liquid-based ultrasound-assisted in-situ solvent formationmicroextraction (IL-UA-ISFME) in combination with high-performance liquid chromatographyultravioletdetection (HPLC-UV) has been successfully developed for the trace determination offive selected polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. In thismethod, a hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) wasformed by addition of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) tosample solution containing an ion-pairing agent (NaPF6). The analytes were extracted into the ionicliquid phase while the microextraction solvent was dispersed through the sample by utilizingultrasonic radiation. The sample was then centrifuged and extracting phase retracted into themicrosyringe, diluted with acetonitrile, and injected to HPLC. In the beginning, effectiveparameters controlling the performance of the microextraction process were studied in detail andoptimized. The limit of detections (LOD, S/N = 3) were in the range of 0.32-0.79 μg L-1 while theRSD% values were below than 5.2% (n = 6). A good linearity (0.997 ≥ r2 ≥ 0.992) and a broadlinear over the concentration ranges from 1 to 500 μg L-1 were achieved. The method wasultimately applied for the preconcentration and sensitive determination of the PAHs in severalenvironmental 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 thatcomplicated matrixes had almost little effect on the developed analytical procedure. Manuscript profile