6 In this study, a total of 370 rice samples collected from six provinces in China were 7 surveyed for the presence of aflatoxins (AFs) and ochratoxin A (OTA) using 8 dispersive liquid-liquid microextraction coupled to liquid chromatography with 9 fluorescence detection. The results obtained in this survey showed that 63.5% 10 (235/370) and 4.9% (18/370) of rice samples contained detectable amo...

Micro-seismicity induced by fluid migration can be used to monitor the migration of fluids during reservoir production and hydro-fracturing operations. The seismicity is usually monitored with sparse networks of seismic sensors. The sparsity of the sensor networks degrades the accuracy of the estimated event locations. This inaccuracy often makes it impossible to infer the fluid pathways at the...

Six ionic liquids (ILs) were applied for the first time as solvents in the extraction and preconcentration of deoxyribonucleic acid (DNA) using an in situ dispersive liquid-liquid microextraction (DLLME) approach. The effect of different IL substituents and functional group on the extraction efficiency of DNA was investigated. The highest extraction efficiencies of DNA were obtained using 1-(1,...

This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L-1 sodium chloride, liquid membrane containing 1-oc...

Deep eutectic solvents (DES) as a new kind of green solvent were used for the first time to excellently extract phenolic compounds from model oil. It was also proved that DES could be used to extract other polar compounds from non-polar or weakly-polar solvents by liquid-phase microextraction.

A novel and low solvent consumption method for the sensitive determination of fungicide residues in wine samples is proposed. Analytes were extracted by dispersive liquid-liquid microextraction (DLLME) and further determined by gas chromatography-mass spectrometry (GC-MS). Under optimized conditions, a binary mixture of acetone and 1-undecanol (0.5 and 0.05 mL, respectively) was used to extract...

Kleinová J., Klejdus B. (2014): Determination of volatiles in beer using solid-phase microextraction in combination with gas chromatography/mass spectrometry. Czech J: Food Sci., 32: 241–248. Headspace solid phase microextraction and purge and trap analysis were used for the determination of volatiles in beer. These methods were compared with the analysis of unconcentrated gas phase and liquid ...

Electromembrane extraction (EME) was published for the first time in 2006, and is a liquid-phase microextraction technique intended for analytical sample preparation. In EME, charged analytes are extracted in an electrical field, from the aqueous sample solution, through a supported liquid membrane and into an aqueous acceptor phase. EME is still in an early stage of development, although nearl...

In order to combat a variety of pests, pesticides are widely used in fruits. Several extraction procedures (liquid extraction, single drop microextraction, microwave-assisted extraction, pressurized liquid extraction, supercritical fluid extraction, solid-phase extraction, solid-phase microextraction, matrix solid-phase dispersion, and stir bar sorptive extraction) have been reported to determi...

Dispersive liquid-liquid microextraction (DLLME) coupled with ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) was developed for the extraction and determination of 10 β2-agonists in animal urine. Some experimental parameters, such as the type and volume of the extraction solvent, the concentration of the dispersant, the salt concentration, the pH value of the ...