A versatile continuous-flow synthesis of highly functionalized 1,2,4-oxadiazoles starting from carboxylic acids is reported. This process was applied to the multistep synthesis of imidazo[1,2-a]pyridin-2-yl-1,2,4-oxadiazoles, using a three reactor, multistep continuous-flow system without isolation of intermediates. This continuous-flow method was successfully combined with a single-step liquid...

Triazole fungicides are systemic fungicides applied to protect crops from fungus infections. Its use must be controlled due to the potential harmful effects in environment and human health. Before determination with a chromatographic system, analyte must be isolated and preconcentrated with an extraction step. This review presents the most used microextraction techniques for those compounds in ...

a user-friendly and inexpensive ionic liquid-based single-drop microextraction (il-sdme) method was developed to preconcentrate trace amounts of aminophenol isomers (aps) from human urine, hair dye and water samples prior to analysis by high performance liquid chromatography-ultraviolet spectrophotometry detection (hplc-uv). under optimum conditions (i.e., 3.5 µl of 1-hexyl-3-methylimidazolium ...

in this study, a sensitive method of dispersive liquid phase microextraction based on ion-pair combined with the flame atomic absorption spectrometry was proposed for the determination of trace ni(ii) using aliquat 336-chloride as ion pair agent. several factors which have effect on  the microextraction efficiency of ni(ii), such as ph, extraction and dispersive solvent type and their volume, c...

an efficient separation-preconcentration procedure namely hollow fiber solid/liquid phase microextraction (hf-slpme) was developed for determination of trace amounts of palladium in water samples by differential pulse voltammetry. in this method, a hybrid sorbent utilizing functionalized nanoparticles incorporated in an organic solvent was used as the extractor phase. the nanoparticle dis­perse...

Dispersive liquid-liquid microextraction method (DLLME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was used to determine thiamine (B1), nicotinamide (B3) and pyridoxine (B6) in sour cherry juice. This method was rapid, simple and sensitive. Separation was accomplished using a C18 column. The optimum chromatographic conditions were found to be: mobile ph...

Dispersive liquid-liquid microextraction method (DLLME) combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was used to determine thiamine (B1), nicotinamide (B3) and pyridoxine (B6) in sour cherry juice. This method was rapid, simple and sensitive. Separation was accomplished using a C18 column. The optimum chromatographic conditions were found to be: mobile ph...

An effective and environmentally friendly method based on ionic liquid-based ultrasound-assisted emulsification microextraction (IL-USAEME) and high performance liquid chromatography (HPLC) has been developed for the determination of nine hormones including three glucocorticoids, one androgen and five progestogens in cosmetics. Several factors that affect the extraction efficiency, such as the ...

Extraction and determination of naproxen from human plasma were performed using Vortex-Assisted Inverted Dispersive Liquid-Liquid MicroExtraction (VA−IDLLME) and High-Performance Liquid Chromatography (HPLC). The parameters affecting extraction recovery such as type and volume of extraction and disperser solvents, pH of sample solution, stirring rate, extraction time and salt addition were ...