Length-controlled hydrophobic CF-COF as a highly efficient absorbent coating for dual-mode solid-phase microextraction of sixteen polycyclic aromatic hydrocarbons in water samples.

Polycyclic aromatic hydrocarbons (PAHs), a group of seriously hazardous environmental contaminants, have attracted extensive attention due to their carcinogenicity, genotoxicity, mutagenicity, and ubiquity. In this work, the excellent hydrophobic trifluoromethyl-enriched covalent organic framework (CF-COF) was designed and synthesized as coating of solid-phase microextraction (SPME). The CF-COF offered a high adsorption selectivity for PAHs, which could be attributed to the multiple interactions between the CF-COF and PAHs, including hydrophobicity interaction, π-π and H bond interactions.

[Determination of fluorescent whitening agents in plastic food contact materials by high performance liquid chromatography with fluorescence detector].

A method for the determination of fluorescent whitening agents in plastic food contact materials by high performance liquid chromatography (HPLC) with fluorescence detector was developed. The samples were extracted with trichloromethane by sonication for 30 min at 40 degrees C. The HPLC method was performed on a column of Eclipse XDB-C18 (250 mm x 4.

[Determination of ten aminoglycoside residues in milk and dairy products using high performance liquid chromatography-tandem mass spectrometry].

A high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/ MS) analytical method was developed for the simultaneous determination of ten aminoglycoside residues (streptomycin, dihydrostrepmycin, neomycin, kanamycin, tobramycin, gentamycin, apramycin, hygromycin B, paromomycin, and amkacin) in milk and dairy products. The sample was extracted with 5% trichloroacetic acid aqueous solution, then the extract was purified by a hydrophilic-lipophilic balance (HLB) cartridge. The ten aminoglycoside residues were separated by ion-pair reversed phase high performance liquid chromatography.

Simultaneous determination of multiresidual phenyl acetanilide pesticides in different food commodities by solid-phase cleanup and gas chromatography-mass spectrometry.

An efficient and sensitive multiresidue method has been developed for quantification and confirmation of 25 phenyl acetanilide pesticides in a wide variety of food commodities including maize, spinach, mushroom, apple, soybean, chestnut, tea, beef, cattle liver, chicken, fish, and milk. Analytes were extracted with acetone-n-hexane (1:2, v/v) followed by cleanup using SPE. Several types of adsorbents were evaluated.

[Rapid screening and confirmation of hormones in health foods by high performance liquid chromatography-ion trap-time of flight tandem mass spectrometry].

A method was developed for the screening, confirmation and quantification of 21 hormones including progesterones, etrogens, glucocorticoids and resorcylic acid lactones in health foods by high performance liquid chromatography-ion trap-time of flight tandem mass spectrometry (HPLC-IT-TOF-MS). The analytes in the sample were extracted with acetonitrile containing 1.0% (v/v) acetic acid and the extract was purified with the mixed QuEChERS sorbents.

[Magnetic multi-walled carbon nanotubes as a solid phase extraction adsorbent for the determination of 13 phthalate acid esters in water samples by gas chromatography-mass spectrometry].

A method based on solid phase extraction (SPE) with magnetic multi-walled carbon nanotubes (MWCNTs) as adsorbent was developed for the determination of 13 phthalate acid esters (PAEs) in water samples by gas chromatography-mass spectrometry (GC-MS). The factors affecting the extraction efficiency, such as extraction time, pH of water sample, desorption solvent, and desorption time, were carefully investigated. The optimized conditions were as follows: extraction time, 10 min; pH of water samples, 5 - 7; desorption solvent, 2 mL acetone; desorption time, 5 min.