Determination of Tertiary-butylhydroquinone and Its Metabolites in Rat Serum by Liquid Chromatography–Ion Trap Mass Spectrometry

A new method applying sensitive and selective liquid chromatography coupled with mass spectrometry (LC/MS/MS) for analyzing tertiary-butylhydroquinone (TBHQ) and its metabolites in rat serum was validated. Using an extracted ion chromatogram (EIC) of m/z 149, free TBHQ was observed in rat serum after dosing TBHQ at 350 mg/kg to male and female Sprague–Dawley (SD) rats. Four major metabolites of TBHQ were identified—a TBHQ-sulfate, two TBHQ-sulfate-derived substances and a TBHQ-glucuronide through MSⁿ spectra. Besides its simplicity, the sample treatment allows one to obtain a very good recovery of analysts, namely around 95%. This result suggests that the method described here is useful for the analysis of TBHQ and its metabolites in rat serum. Moreover, the metabolism of TBHQ was investigated using the method. After oral administration, TBHQ appear to be more completely absorbed and bio-transformed by males than females, which may result in higher acute oral toxicity of TBHQ for males than females.     

茶树油的分子蒸馏精制及其GC/MS分析

利用新型、特殊分离技术——分子蒸馏对茶树油进行精制,并对精制后的茶树油进行GC/MS定性分析及其总离子流图的面积归一法定量分析。结果从粗茶树油中分离出了61种化合物,鉴定出36种组分,占总量的98.67%,其中4-松油醇高达49.56%,并且精制的茶树油符合国际标准(ISO 4730-1996)。     

浅谈基础化学实验教学中如何提高学生学习的积极性

在高等学校的教学中,实验教学占有十分重要的地位。为了促进基础化学实验课程教学质量的提高,文章结合自身的教学实践,对如何在基础化学实验教学中提高学生学习的积极性作了探讨,方法有四种,列举如下:将多媒体技术和网络引入实验预习过程中;根据不同专业的特点加强背景知识介绍;利用学生的争强好胜心理开展小组实验竞赛;多样化管理平时实验成绩。     

有机化学实验教学的改革与探索

文章对有机化学实验教学中的一些问题进行探讨,主要包括实验教学内容、教学方法手段、学生实验操作技能、创新能力培养和考核评价体系等几个方面,提出了学生综合素质和创新能力培养的方法,实现教与学的互动,确保实验教学质量的提高。在实验开设中引入新思路和新方法,如开设微型化实验以厉行节约减少污染、将微波技术应用于有机合成实验。     

Monodispersed gold nanoparticles supported on γ-Al2O3 for enhancement of low-temperature catalytic oxidation of CO

Monodispersed nano-Au/γ-Al₂O₃ catalysts for low-temperature oxidation of CO have been prepared via a modified colloidal deposition route, which involves the deposition of dodecanethiolate self-assembled monolayer (SAM)-protected gold nanoparticles (C₁₂ nano-Au) in hexane on γ-Al₂O₃ at room temperature. The diameter of the gold nanoparticles deposited on the support is 2.5 ± 0.8 nm after thermal treatment, and their valence states comprise both the metallic and oxidized states. It is found that the thermal treatment temperature affects significantly the catalytic activity of the catalysts in the processing steps. The catalyst treated at 190 °C exhibits considerably higher activity as compared to catalysts treated at 165 and 250 °C. A 2.0-wt.% nano-Au/γ-Al₂O₃ catalyst treated at 190 °C for 15 h maintains the catalytic activity at nearly 100% CO oxidation for at least 800 h at 15 °C, at least 600 h at 0 °C, and even longer than 450 h at −5 °C. Evidently, the catalysts obtained using this preparation route show high catalytic activity, particularly at low temperatures, and a good long-term stability.     

氧化锆材料种类及应用

论述了氧化锆的基本性能,并对氧化锆材料自问世以来被人类所利用的领域进行了详细的研究,发现目前除被广泛应用于传统领域耐火材料、结构材料、功能材料、宝石材料之外,正逐渐被装饰陶瓷所采纳,如彩色氧化锆陶瓷、陶瓷首饰等异军突起,成为装饰陶瓷领域的一支奇琶,倍受世人瞩目。     

焦炉非接触全自动连续测温技术

介绍了焦炉非接触全自动测温系统的工作原理、系统构成及可靠性分析,实际应用证明其测温精度高于目前的人工测温,为焦炉测温提供了一套全新的方法.     

壳聚糖／水溶性高分子共混膜相容性的预测与表征

高分子（聚乙烯醇和聚乙二醇）间的相容性,壳聚糖与极性水溶性高分子在溶液状态时,分子间相互吸引,相容性好,向本体转化而成膜时,CS／PVA体系比CS／PEG体系有更好的本体相容性。原因可归结为PEG不能像PVA一样提供足够多的极性基团与壳聚糖分子形成强烈相互作用,CS与PEG间的氢键强度要弱于CS与PVA间的氢键;另一个方面,PEG结晶能力很强,在由溶液转化为本体而成膜过程中,PEG分子自身之间易于形成较规整的结晶而逐渐使体系发生分相。     

新型混粉电火花镜面加工实验装置的研制

针对混粉电火花加工的实验装置成本高、电蚀产物分离难等问题,利用水力旋流器超细分级分离的特性,设计了可在线过滤混粉电火花加工工作液的新型实验装置,同时设计了新型的储液箱搅拌系统和工作液体槽内的搅拌装置,能很好地保证混粉电火花加工过程中粉末浓度的均匀性.该实验装置的研制为将来实现混粉、常规电火花加工工作液箱一体化的电火花成形机提供了可行性验证.     

Preparation and characterization of electrospun,biodegradable membranes

Nonwoven, biodegradable membranes fabricated by electrospinning have recently attracted a great deal of attention for biomedical applications. In this study, microporous, nonwoven membranes of poly(L ‐lactide) and its copolymers and blends were fabricated through electrospinning. The structures and morphologies of the electrospun membranes were investigated with scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction. Different polymer membranes, incorporated with carmofur, were fabricated, and their drug release profiles were investigated. Scanning electron microscopy images showed that the fiber diameters were down to the nanometer range. The diameters and morphologies of thenanofibers depended on processing parameters such as the solution properties (concentration and polymer molecular weight), applied electric voltage, solution feeding rate, and needle diameter. Differential scanning calorimetry showed that the crystallinity of the electrospun membranes was lower than that of the cast film. For all the membranes incorporated with the drug, there was a burst release in the first 10 h of incubation in phosphate‐buffered saline at 37°C. Poly(glycolide‐co‐lactide) membranes showed faster and more complete drug release than poly(L ‐lactide), and this could be attributed to its faster degradation. The incorporation of polylactide–poly(ethylene glycol) could shorten the drug release time. A combination of suitable degradable biomaterials with an appropriate electrospinning process could be useful in the fabrication of a new kind of membrane suitable for different biomedical applications such as tissue engineering and drug delivery. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008