Facile synthesis of uniform spherical covalent organic frameworks for determination of neonicotinoid insecticides.

A uniform spherical structure covalent organic framework (TAPA-BPDA-COF) was prepared by a facile method at room temperature with tris(4-aminophenyl)amine (TAPA) and 4,4'-biphenyldicarboxaldehyde (BPDA) as building blocks. Based on the solid phase extraction with the TAPA-BPDA-COF as the sorbent and high performance liquid chromatography-diode array detection, a sensitive analytical method was established for the determination of four neonicotinoid insecticides from water and honey samples. Under the optimum conditions, good linear response for the quantification of the analytes was achieved in the range of 0.

Benzoxazine Porous Organic Polymer as an Efficient Solid-Phase Extraction Adsorbent for the Enrichment of Chlorophenols from Water and Honey Samples.

Porous organic polymers have gained great research interest in the field of adsorption. A benzoxazine porous organic polymer (BoxPOP) constructed from p-phenylenediamine, 1,3,5-trihydroxybenzene and paraformaldehyde was fabricated and explored as an adsorbent for solid-phase extraction (SPE) of four chlorophenols from water and honey samples. Under the optimized SPE conditions, the response linearity for the analysis of the SPE extract of the chlorophenols by high performance liquid chromatography-diode array detector was observed in the range of 0.

[Determination of serum proteins by resonance light scattering method with lidocaine as a probe].

A new method for the determination of bovine serum albumin (BSA) and human serum albumin (HSA) was developed by using resonance light scattering (RLS) technique via an interaction of serum albumin with lidocaine and sodium dodecylbenzene sulphonate (SDBS). The RLS intensity of serum albumin was enhanced in the presence of lidocaine and SDBS. The influences of some experimental factors, including incubation time, addition sequence of reagents, pH values, foreign substances and the concentrations of lidocaine and SDBS, on the enhancement of the RLS intensity were investigated.

Determination of triazine herbicides in environmental water samples by high-performance liquid chromatography using graphene-coated magnetic nanoparticles as adsorbent.

In this paper, a graphene-based Fe(3)O(4) magnetic nanoparticles (G-Fe(3)O(4) MNPs) was used as the adsorbent for the magnetic solid-phase extraction of some triazine herbicides (atrazine, prometon, propazine and prometryn) in environmental water samples followed by high performance liquid chromatography-diode array detection (HPLC-DAD). After the extraction, the adsorbent can be conveniently separated from the aqueous samples by an external magnet. The main factors influencing the extraction efficiency including the amount of the MNPs, the extraction time, the pH of sample solution, and desorption conditions were studied and optimized.

N'-(5-Bromo-2-hy-droxy-benzyl-idene)-4-nitro-benzohydrazide methanol monosolvate.

In the title compound, C(14)H(10)BrN(3)O(4)·CH(4)O, the benzohydrazide mol-ecule is nearly planar [maximum deviation = 0.110 (2) Å]. The mean planes of the two benzene rings make a dihedral angle of 8.

[Study on the interaction of tetrandrine and bovine serum albumin].

The interaction of tetrandrine with bovine serum albumin was studied by fluorescence spectra and ultra-violet spectra. The results showed that tetrandrine could quench the intrinsic fluorescence of BSA. Both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching.

[Study on the interaction of Nimodipine and bovine serum albumin by fluorescence quenching method].

The interaction of Nimodipine and bovine serum albumin (BSA) was studied using fluorescence spectroscopy (FS) and ultraviolet spectroscopy (UV). The apparent binding constants (KA) between Nimodipine and BSA were 5.01 x 10(4) (26 degrees C) and 4.

[Determination of carbamate pesticides in reservoir water by hollow fiber-based liquid phase microextraction coupled with high performance liquid chromatography].

An analytical method for the determination of carbamate pesticides (carbofuran, carbaryl, isoprocarb and diethofencarb) in reservoir water using hollow fiber-based liquid phase microextraction (HF-LPME) coupled with high performance liquid chromatography (HPLC) was developed. Some main experimental parameters that affect the extraction efficiency were optimized. Toluene was selected as both the extraction solvent and the impregnation solvent.

[Study on the interaction between brucine and bovine serum albumin].

The interaction between brucine and bovine serum albumin (BSA) was investigated using fluorescence spectroscopy (FS) and ultraviolet spectroscopy (UV). The experimental results showed that the brucine quenches the inner fluorescence by forming a brucine-BSA complex. It was found that both static quenching and non-radiation energy transfer were the main reasons for the fluorescence quenching.

[Simultaneous determination of levodopa and methyldopa in human serum by capillary electrophoresis].

A simple capillary electrophoresis method was developed for the determination of levodopa and methyldopa in human serum. The effects of pH and concentration of buffer, voltage and injection time on separation were investigated. As a result, an optimized separation was obtained with a fused-silica capillary of 60.