Ultrasound-assisted Magnetic Solid Phase Extraction Research Articles

Ultrasound-assisted mixed hemimicelle magnetic solid phase extraction followed by high performance liquid chromatography for the quantification of atorvastatin in biological and aquatic samples

A method based on ultrasound-assisted magnetic solid phase extraction and HPLC-UV-Vis was developed for the isolation and preconcentration of atorvastatin using sodium dodecyl sulfate coated Fe3O4 magnetic nanoparticles.

Ultrasound-assisted magnetic solid-phase extraction for the determination of some transition metals in Orujo spirit samples by capillary electrophoresis

Ultrasound-assisted magnetic solid-phase extraction coupled to capillary electrophoresis was optimized for the preconcentration and determination of Zn(II), Cu(II), Mn(II) and Cd(II) as their complexes with 1,10-phenanthroline (Phen). Both pre- and on-capillary complexations were employed to obtain stable metal–Phen complexes. The parameters that have an influence on the electrophoretic separation and the MSPE process were studied and optimized using different experimental designs. Metals were extracted from 10mL of sample at pH 5 using 3mg of magnetic particles functionalized with carboxylic groups. The metals were eluted as metal–Phen complexes and analyzed by capillary electrophoresis. The method showed low limits of detection for metals 0.49–2.19μgL−1, and high preconcentration factors, 39–44, The efficiencies of the extraction method were in the range 77.1–87.5% and the precision (RSD<10%) and accuracy were between 98.2% and 101.6%. The method was applied to the determination of the aforementioned metals in Galician Orujo spirit samples.

Solid-phase extraction based on chloromethylated polystyrene magnetic nanospheres followed by gas chromatography with mass spectrometry to determine phthalate esters in beverages.

An ultrasound-assisted magnetic solid-phase extraction procedure with chloromethylated polystyrene-coated Fe3 O4 nanospheres as magnetic adsorbents has been developed to determine eight phthalate esters (bis(4-methyl-2-pentyl) phthalate, dipentyl phthalate, dihexyl phthalate, benzyl butyl phthalate, bis(2-butoxyethyl) phthalate, dicyclohexyl phthalate, di-n-octyl phthalate, and dinonyl phthalate) simultaneously in beverage samples, in combination with gas chromatography coupled to tandem mass spectrometry for the first time. Several factors related to magnetic solid-phase extraction efficiencies, such as amount of adsorbent, extracting time, ionic strength, and desorption conditions were investigated. The enrichment factors of the method for the eight analytes were over 2482. A good linearity was observed in the range of 10-500 ng/L for bis(2-butoxyethyl) phthalate and 2-500 ng/L for the other phthalate esters with correlation coefficients ranging from 0.9980 to 0.9998. The limits of detection and quantification for the eight phthalate esters were in the range of 0.20-2.90 and 0.67-9.67 ng/L, respectively. The mean recoveries at three spiked levels were 75.8-117.7%, the coefficients of variations were <11.6%. The proposed method was demonstrated to be a simple and efficient technique for the trace analysis of the phthalate esters in beverage samples.

Ultrasound-assisted magnetic solid-phase extraction based ionic liquid-coated Fe3O4@graphene for the determination of nitrobenzene compounds in environmental water samples

An ultrasound-assisted magnetic solid-phase extraction procedure with the [C7MIM][PF6] ionic liquid-coated Fe3O4-grafted graphene nanocomposite as the magnetic adsorbent has been developed for the determination of five nitrobenzene compounds (NBs) in environmental water samples, in combination with high performance liquid chromatography-photodiode array detector (HPLC-PDA). Several significant factors that affect the extraction efficiency, such as the types of magnetic nanoparticle and ionic liquid, the volume of ionic liquid and the amount of magnetic nanoparticles, extraction time, ionic strength, and solution pH, were investigated. With the assistance of ultrasound, adsorbing nitrobenzene compounds by ionic liquid and self-aggregating ionic liquid onto the surface of the Fe3O4-grafted graphene proceeded synchronously, which made the extraction achieved the maximum within 20 min using only 144 μL [C7MIM][PF6] and 3mg Fe3O4-grafted graphene. Under the optimized conditions, satisfactory linearities were obtained for all NBs with correlation coefficients larger than 0.9990. The mean recoveries at two spiked levels ranged from 80.35 to 102.77%. Attributed to the convenient magnetic separation, the Fe3O4-grafted graphene could be recycled many times. The proposed method was demonstrated to be feasible, simple, solvent-saving and easy to operate for the trace analysis of NBs in environmental water samples.