RESUMEN
A capacitively coupled contactless conductivity detector for high performance liquid chromatography was developed. The detector was consisted of a signal generator, a signal amplifier, and a pair of tubular electrodes. A plastic connecting tube following the separation column was threaded through the two tubular electrodes. When the separated components passed the region between two tubular electrodes, they would be sensed. The instrumental parameters of this detector were investigated, including the internal diameter of connecting tube,the frequency and voltage of excitation signal, electrodes length, and the gap between two electrodes. The 0.5 mm of internal diameter of connecting tube, 70 kHz of excitation frequency, 60 V of excitation voltage,10 mm of electrodes length and 1.5 mm of gap between two electrodes were finally found to be the best working conditions for the detector. This HPLC-C4D(capacitively coupled contactless conductivity detector) was applied to the analysis of oleic and linoleic acids in Brucea javanica oil. The chromatographic peak area was linear with concentration for oleic and linoleic acids in 5-1000 μg/mL, and the limit of detection reached 2.5 μg/mL and 1.0 μg/mL,respectively. The results demonstrate that the present method is sensitive and accurate, proving this homemade contactless conductivity detector has a great application potential for pharmaceutical analysis in future development.
RESUMEN
With the continuous development in microfluidic fabrication technology, microfluidic analysis has evolved from a concept to one of research frontiers in last twenty years. The research of enzymes and enzyme inhibitors based on microfluidic devices has also made great progress. Microfluidic technology improved greatly the analytical performance of the research of enzymes and enzyme inhibitors by reducing the consumption of reagents, decreasing the analysis time, and developing automation. This review focuses on the development and classification of enzymes and enzyme inhibitors research based on microfluidic devices.
Asunto(s)
Inhibidores Enzimáticos , Metabolismo , Enzimas , Metabolismo , Técnicas Analíticas Microfluídicas , Métodos , Microfluídica , MétodosRESUMEN
5-Aryl-4-cyano-1H-1, 2, 3-triazoles bearing a variety of substituting groups on 5-phenyl were synthesized. Their structures were established by MS, IR and 1H NMR spectra. The crystal structures of compounds 3f and 3m were determined by X-ray diffraction analysis. The active H of the triazole was on 1-N from the crystal structures. The compounds, designed as HER2 tyrosine kinase inhibitors, were screened for bioactivity of growth-inhibition of breast cancer MDA-MB-453 cells. The lowest IC50 value of inhibiting HER2 tyrosine kinase phosphorylation in breast cancer cells is 6.6 micromol x L(-1). The inhibiting-growth of breast cancer cells was enhanced from electron-drawing groups joining 5-phenyl on the triazole.