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861.
Xianqin Wang Zheng Xiang Xiaojun Cai Haiya Wu Xuebao Wang Junwei Li Meiling Zhang 《Biomedical chromatography : BMC》2011,25(7):833-837
A sensitive and selective liquid chromatography–tandem mass spectrometry method for the determination of pethidine in human plasma was developed and validated over the concentration range of 4–2000 ng/mL. After addition of ketamine as internal standard, liquid–liquid extraction was used to produce a protein‐free extract. Chromatographic separation was achieved on a 100 × 2.1 mm, 5 µm particle, AllureTM PFP propyl column, with 45:40:15 (v/v/v) acetonitrile–methanol–water containing 0.2% formic acid as mobile phase. The MS data acquisition was accomplished by multiple reactions monitoring mode with positive electrospray ionization interface. The lower limit of quantification was 4 ng/mL; for inter‐day and intra‐day tests, the precision (RSD) for the entire validation was less than 7%, and the accuracy was within 95.9–106.5%. The method is sensitive and simple, and was successfully applied to analysis of samples of clinical intoxication. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
862.
Bacterial cellulose (BC)/poly(ethylene glycol) (PEG) composite was prepared by immersing wet BC pellicle in PEG aqueous solution
followed by freeze-drying process. The product looks like a foam structure. The morphology of BC/PEG composite was examined
by scanning electron microscope (SEM) and compared with pristine BC. SEM images showed that PEG molecules was not only coated
on the BC fibrils surface but also penetrated into BC fiber networks. It has very well interconnected porous network structure
and large aspect surface. The composite was also characterized by Fourier transform infrared spectrum, X-ray diffraction,
thermogravimetric analysis (TGA) and tensile test. It was found that the presence of PEG affected the preferential orientation
of the (1[`1]0 1\bar{1}0 ) plane during the drying process of BC pellicle, which in turn decrease the crystallinity of dried BC. The TGA result showed
that the thermal stability was improved from 263 to 293 °C, which might be associated with strong interaction between BC and
PEG. Tensile test results indicate that the Young’s modulus and tensile strength tend to decrease. Biocompatibility of composite
was preliminarily evaluated by cell adhesion studies using 3T3 fibroblast cells. The cells incubated with BC/PEG scaffolds
for 48 h were capable of forming cell adhesion and proliferation, which showed much better biocompatibility than the pure
BC. The prepared BC/PEG scaffolds can be used for wound dressing or tissue-engineering scaffolds. 相似文献
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Jian‐lin Wu Jie Liu Zongwei Cai 《Rapid communications in mass spectrometry : RCM》2010,24(13):1828-1834
Triclosan is a widely used broad‐spectrum antibacterial agent that acts by specifically inhibiting enoyl–acyl carrier protein reductase. An in vitro metabolic study of triclosan was performed by using Sprague‐Dawley (SD) rat liver S9 and microsome, while the in vivo metabolism was investigated on SD rats. Twelve metabolites were identified by using in‐source fragmentation from high‐performance liquid chromatography/negative atmospheric pressure chemical ionization ion trap mass spectrometry (HPLC/APCI‐ITMS) analysis. Compared to electrospray ionization mass spectrometry (ESI‐MS) and tandem mass spectrometry (MS/MS) that gave little fragmentation for triclosan and its metabolites, the in‐source fragmentation under APCI provided intensive fragmentations for the structural identifications. The in vitro metabolic rate of triclosan was quantitatively determined by using HPLC/ESI‐ITMS with the monitoring of the selected triclosan molecular ion. The metabolism results indicated that glucuronidation and sulfonation were the major pathways of phase II metabolism and the hydroxylated products were the major phase I metabolites. Moreover, glucose, mercapturic acid and cysteine conjugates of triclosan were also observed in the urine samples of rats orally administrated with triclosan. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
867.
Indole is an important heterocycle substance which could be used to produce indigo dye, perfume, forage additive and tryptophan[1~3]. Although there are some methods to produce indole[4], one of the most promising routes, from an industrial point of view, seems to be the direct synthesis from aniline and ethylene glycol[5]. This is a one step reaction from reactants to indole and the starting materials are inexpensive. 相似文献
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介绍了研究分子反应动力学的两大主要实验方法之一的气室法、在研究有热原子参与的反应所取得的新进展,讲述了此方法“新用”的理论依据及相应的实验条件,至此,可以获得对分子反应动力学更精细的信息,例如,态-态分辨的微分反应截面,并对两大方法进行了“现代”对比。还对两方法的发展前景作了适度的分析。 相似文献
870.