自由基介导含氟杂环化合物的构建研究

设计了一个由底物控制的化学选择性合成含氟吡唑、哒嗪酮和吲哚衍生物的实验,采用碳链长度的β,γ和δ-含氟酮酸酯为底物与苯肼在对甲苯磺酸的作用下,并将其应用于对甲苯磺酸的催化体系中。该方法具有操作简单,反应条件温和等特点。利用TLC和FNMR谱追踪该过程,可以利用红外光谱、核磁共振氢谱、氟谱和碳谱及元素分析等对该过程进行了表征和确认,还可以对该研究型实验在该过程中的应用进行了深入的分析。     

溶剂蒸馏气相色谱-质谱法研究菜籽油挥发性成分

溶剂蒸馏气相色谱-质谱法是一种有效的检测挥发性物质的研究方法,在本研究中对菜籽油中挥发性成分进行分析：将菜籽油和乙酸乙酯（V／V=2：1）混合溶解后蒸馏出溶剂,同时将蒸馏出来的挥发性组分进行富集,然后加热并用N2吹扫蒸馏液浓缩得到待测液,最后用GC／MS分析检测待测液成分。结果检测到挥发性成分46种,通过NIST 2006标准谱库检索、Wiley数据库和文献比较确定挥发性成分28种,分别是酮类、醛类、烷烃类、烯烃类以及其他少量化合物。     

陶瓷厂球磨机齿轮减速箱倒频谱故障诊断法

介绍了倒频谱分析的基本原理及在齿轮减速箱故障诊断中的应用.鉴于球磨机齿轮减速箱振动信号中调制源多、频率成分复杂,功率谱中存在大量的非对称边频带及周期性结构信号导致故障识别工作困难的问题,运用倒频谱分析法对其进行故障诊断,它能将功率谱上成族的边频带谱线简化为单根谱线,分离和提取出密集泛频信号中的周期成分、多成分边频,快速准确诊断球磨机齿轮减速箱中零件的故障.     

重铬酸钾氧化-外加热法测定化探土壤样品中有机碳含量

采用重铬酸钾氧化-外加热法对化探土壤样品中有机碳含量进行测定,选用19个土壤成分分析国家一级标准物质作为分析试样。实验结果表明,测定标准物质GBW07447、GBW07455、GBW07457精密度分别为6.34%、3.64%、2.17%;准确度实验中所有标准物质的有机碳测定结果令人满意,方法快速、简便、准确。利用油浴(液体石蜡)消煮可以同时处理多个样品。该方法可用于多目标区域地球化学调查工作中土壤样品有机碳含量的测定,很大程度上提高了工作效率。     

基于倒频谱分析的球磨机减速机故障诊断

介绍了倒频谱分析的基本原理及在齿轮减速箱故障诊断中的应用。鉴于球磨机齿轮减速箱振动信号中调制源多、频率成分复杂，功率谱中存在大量的非对称边频带及周期性结构信号导致故障识别工作困难的问题，运用倒频谱分析法对其进行故障诊断，它能将功率谱上成族的边频带谱线简化为单根谱线，分离和提取出密集泛频信号中的周期成分、多成分边频，快速准确诊断球磨机齿轮减速箱中零件的故障。     

Py-GCMS和NMR联用在涂料乳化剂未知组分剖析中的应用

介绍了热裂解气相色谱-质谱(Py-GCMS)、核磁共振谱(NMR)在未知结构的涂料乳化剂配方剖析中的应用。其中,核磁共振包含多种方法,分别是氢谱(1H NMR)、碳谱(13C NMR)、二维核磁共振谱(2D NMR)、扩散排序技术(DOSY NMR)以及定量核磁共振(QNMR)。通过以上方法的联用,对未知乳化剂各成分进行了定性和定量分析,得到了配方中主体成分和溶剂的种类及含量,为未知混合物配方的剖析提供了一种新思路。     

遥控器导电胶键碳粒粘连的失效分析

针对某型号遥控器使用一段时间后出现转换按键无法回弹的问题,从导电胶键碳粒的材料、硫化工艺及其显微结构等方面进行分析。通过确定粘连处残留物的成分;对比发生粘连碳粒和正常碳粒、一次硫化碳粒和二次硫化碳粒的成分差异;对不同碳粒表面的结构进行观察。结果表明:残留物的成分与碳粒成分一致;碳粒粘连发生的原因为硅橡胶发生了老化,与其二次硫化不足有关;减小碳粒表面凹槽的直径,提高表面规整度可减弱其老化行为。     

12-苯甲酰基脱氢松香异硫氰酸酯的合成与光谱性质

以歧化松香为原料,将其纯化得到脱氢松香酸,用硫酸二甲酯酯化后,通过傅克酰基化、水解、酰氯化、Curtius反应得到中间体12-苯甲酰基脱氢松香胺,再由CS2法得到标题化合物。采用核磁共振氢谱、碳谱、红外光谱、质谱、元素分析等测试技术对产物进行了结构表征,并对其紫外光谱、荧光光谱等光学性质进行了初步的研究。     

二氧化碳和环氧丙烷共聚催化剂的合成与活性研究

二氧化碳是导致温室效应的主要气体,是自然界中来源广泛、价格低廉的碳资源,其有效利用一直备受关注。本文设计合成了Co、Zn、Fe三种salen催化剂,并用于催化二氧化碳与环氧丙烷共聚反应;探究了三种催化剂对共聚反应的催化活性;通过红外光谱分析、元素分析、核磁氢谱对合成配体与催化剂的结构进行了表征,并通过核磁氢谱确认了共聚产物成分。结果表明,Salen Co表现出较高的催化活性,具有潜在的应用价值。     

建立HPLC-DAD-MS/MS指纹图谱快速分析农药隐性成分的方法

[目的]利用高效液相色谱-二级管阵列-串联质谱(HPLC-DAD-MS/MS)联用技术,建立了194种常用农药品种的标准指纹谱图库,检测农药产品中的隐性成分,对农药市场进行有效管理和评价。[方法]在离子优化的基础上,采用tMRM(动态多反应监测)模式的分析技术,建立HPLC-MS/MS标准指纹谱图库。[结果]自建了标准指纹谱图库,并对啶虫脒、三唑磷和硝磺草酮3个农药品种进行了隐性成分鉴定,共检出了吡虫啉、氧乐果、马拉硫磷、磺草酮、灭草松和烯草酮等6种隐性成分,匹配性良好。[结论]所建立的HPLC-DAD-MS/MS指纹谱图快速分析农药隐性成分的方法快速有效,特征性和专属性强,为规范农药产品质量、打击农药假冒产品提供了可靠的方法。     

茶叶中稀土污染调查研究

探讨深圳市茶叶稀土污染状况,并尝试寻找此类污染的主要原因及解决办法。2009～2010年,笔者在市售产品中抽取绿茶,花茶,红茶,黑茶和乌龙茶共324批次,采用ICP-MS测定样本中稀土含量（以稀土氧化物计）,并按GB2762-2003食品中污染物限量标准评价。绿茶,花茶,红茶,黑茶和乌龙茶的合格率分别为65.8%、54.3%、33.3%、27.7%、14.5%。建议从规范施肥方式、定期监测土壤污染情况、探索治理方法等方面寻找解决办法,同时建立更科学合理的安全评价方法。建议相关部门对取消茶叶稀土限量要求慎重考虑。     

脂溶性茶色素的提取及其稳定性的研究

以乙醇为溶剂从茶叶中提取脂溶性茶色素,研究了温度、pH值、金属离子、氧化剂、还原剂、暗处存放和自然光下存放对脂溶性茶色素稳定性的影响。结果表明：温度对脂溶性茶色素的稳定性影响不大;弱酸性条件（pH=4．8～6．6）下,脂溶性茶色素的稳定性较好;K＋、Cu2＋、Zn2＋、Mg2＋、Al3＋对脂溶性茶色素的稳定性影响较小,Fe3＋、sn2＋对脂溶性茶色素的稳定性影响明显;氧化剂对脂溶性茶色素的稳定性有影响;还原剂对脂溶性茶色素的稳定性影响不大;暗处存放对脂溶性茶色素的稳定性影响不大;自然光下存放对脂溶性茶色素的稳定性影响很大。     

茶儿茶素氧化聚合物抗油脂自动氧化作用的研究

用Na2 S2 O3 I2 滴定法测定了茶儿茶素氧化聚合物对猪油和豆油的抗氧化作用 ,并以茶多酚作比较。结果表明 ,在 30℃见光条件下贮存 2 5d ,相对油质量而言 ,当添加质量分数分别为0 0 0 5 %～ 0 0 2 0 %时 ,茶儿茶素氧化聚合物和茶多酚对猪油氧化的抑制率分别为 43 1%～5 7 0 %和 38 0 %～ 45 2 % ,且两者均在添加质量分数为 0 0 10 %时抗氧化活性最强 ;在 30℃避光条件下 ,茶儿茶素氧化聚合物对豆油体系也显示出同样的抗氧化效果 ;Vc和柠檬酸对儿茶素氧化聚合物具有协同增效作用 ,儿茶素氧化聚合物与Vc或柠檬酸按m(儿茶素氧化聚合物 )∶m(Vc或柠檬酸 ) =1∶1复配 ,可使其抗氧化活性增强 3～ 5倍     

Dyeing of cotton with the natural dye extracted from waste leaves of green tea (Camellia sinensis var. assamica)

Due to an increase in the production of green tea, the amount of leaf waste has increased enormously, causing serious environmental problems. With regard to environmental awareness, the possibility of reusing the waste leaves of green tea as a low‐cost and abundantly available source of natural dye for dyeing cotton fibres was investigated. Natural dye powder from the waste leaves of green tea (NDPT) was successfully applied to dye cotton fibres without mordant by batch experiments. NDPT was obtained as a dark brown powder with a yield of 2.7 ± 0.5% w/w from dried waste leaves of green tea. The optimal conditions for dyeing NDPT onto cotton fibres were: pH of dye solution, 3; material to liquor ratio, 100:1; dyeing time, 180 min; concentration of dye solution, 3.0 mg/ml; and dyeing temperature, 100 °C. The colour of cotton fibres dyed with NDPT was observed to be dark brown. The adsorption data of NDPT on cotton fibres was best fitted with a Langmuir adsorption isotherm model with a correlation coefficient (R²) of 0.997. It is clear that there is a strong possibility of reusing the waste leaves of green tea as a low‐cost and abundantly available source of natural dye for dyeing cotton fibres.     

聚酰胺/硅胶吸附剂在茶多酚提取中的应用

介绍了用聚酰胺／硅胶吸附剂提取茶叶中茶多酚,提取率达12％,茶多酚纯度达85％～90％。     

Preparation of Cold Brew Tea by Explosion Puffing Drying at Variable Temperature and Pressure

Cold brew tea was prepared using explosion puffing drying at variable temperature and pressure. The influences of moisture content of predried tea leaves, freezing pretreatment times at ?18°C, and puffing temperature on water extracts content of cold brew tea were studied according to the orthogonal experiments of processing of cold brew tea based on single factors. The biochemistry ingredients of cold brew tea and hot air–dried green tea were determined and compared. The optimum processing conditions of cold brew tea were obtained as follows: predried tea leaf moisture content 50%, freezing pretreatment three times, puffing temperature 105°C. Under these optimized processing conditions, cold brew tea was obtained. When cold brew tea was soaked in cold water for 30 min at 20°C, the water extracts content, caffeine, tea polyphenols, and free amino acids of cold brew tea reached 18.21, 0.88, 11.86, and 1.02%, respectively. High-performance liquid chromatography (HPLC) analysis showed that the amount of tea catechins in cold brew tea and hot air–dried green tea were 11.74 and 11.47%, respectively. The caffeine in cold brew tea was 3.06%, equal to that in hot air–dried green tea. Experimental results showed that biochemistry ingredients of cold brew tea prepared by explosion puffing drying at variable temperature and pressure difference were easy to extract by low-temperature water. This research provides theory and technical support for industrialized production of cold brew tea.     

Effective and Preparative Separation of Bioactive Flavonoids From Gynostemma Pentaphyllum Tea Using Elution-Extrusion Counter-Current Chromatography

Elution-extrusion counter-current chromatography (EECCC) was successfully applied for screen and separation of four flavonoids from Gynostemma pentaphyllum tea, a popular herbal tea extract in China. With the hexane/ethyl acetate/methanol/water 5/6/5/6 (v/v) system, 300 mg of G. pentaphyllum tea extract were fractionated on a 180 mL-capacity preparative hydrodynamic CCC column. Satisfactory separation efficiency was achieved, producing milligram-amounts of quercetin, isorhamnetin, and cirsiliol over 90% pure in one EECCC process. Due to the hydrophilic property, the major flavonoid glycoside, rutin, was co-eluted with the solvent front as a mixture. Therefore, another carefully selected biphasic liquid system composed of ethyl acetate/n-butanol/water (4/1/5, v/v) was employed, yielding 35 mg of rutin with 97.1% purity. Structures of all separated compounds were identified by ESI-MS, ¹H NMR, and ¹³C NMR.     

茶树花中功能性成分的提取与分析研究

采用分光光度法测定茶多酚、茶多糖等功能性成分含量;用高效液相色谱法测定茶多酚中儿茶素组成成分,离子色谱积分安培法测定多糖中单糖的组成成分。实验表明:茶树花中含茶多酚含量为3.62%~4.48%,总糖为16.15%~23.25%,其中茶多糖为1.60%~1.65%,茶氨酸为3.92%~5.03%,黄酮为0.141%~0.162%。分析结果表明茶树花中功能性成分与茶叶中的成分相似,为进一步开发利用茶树花资源提供理论依据。     

铜仁市四种绿茶茶多酚提取率的比较分析

为对铜仁市茶叶品质成分提供科学依据,用酒石酸亚铁比色法对铜仁市的印江梵净山绿茶、松桃生态绿茶、石阡苔茶、沿河云雾绿茶四县同一季节同一等级茶叶中茶多酚提取率进行比较研究,同时对松桃生态绿茶同一产地不同采收时节茶叶中茶多酚的提取率进行比较研究。结果表明:茶多酚的提取率含量较高的是石阡苔茶,其次是松桃生态绿茶、沿河云雾绿茶、印江梵净山绿茶;松桃县云雾绿茶不同采收时节的茶叶中茶多酚提取率含量较高的是清明茶,其次是清明前茶、谷雨茶、清明后茶。     

Changes of constituents and activity to apoptosis and cell cycle during fermentation of tea

Tea is believed to be beneficial for health, and the effects of the fermentation process on its contributions to apoptosis and cell cycle arrest of gastric cancer cells have not been completely investigated. In this study, the chemical components in green tea, black tea and pu-erh tea aqueous extracts were analyzed and compared. The polysaccharide and caffeine levels were substantially higher in the fermented black tea and pu-erh tea, while the polyphenol level was higher in the unfermented green tea. Hence, a treatment of tea aqueous extract and the components, which are emerging as promising anticancer agents, were pursued to determine whether this treatment could lead to enhance apoptosis and cell cycle arrest. In the human gastric cancer cell line SGC-7901, the cell viability and flow cytometry analysis for apoptotic cells indicated effects in a dose-dependent inhibition manner for the three tea treatment groups. The apoptosis rates were found to be elevated after 48 h of treatment with 31.2, 125, and 500 μg/mL of green tea extract, the higher catechins content may be involved in the mechanism. Cell cycle was arrested in S phase in the fermented black tea and pu-erh tea, and the populations were significantly decreased in G2/M phases, possibly due to the oxidation of tea polyphenols, which causes an increase of theabrownins. CCC-HEL-1 normal cells were not sensitive to tea extract. These findings suggest that the fermentation process causes changes of the compounds which might be involved in the changes of cell proliferation inhibition, apoptosis induction and cell cycle arrest.