共查询到18条相似文献,搜索用时 137 毫秒
1.
目的:应用高效液相色谱法对1,1-环己基二乙酸单酰胺(CAM)及相关物质进行分析测定,建立CAM及相关物质的分析方法[1]。方法:采用Agilent(4.6×250mm)SB-C18为分析柱,磷酸水溶液:乙腈=(70:30)为流动相(pH=1.90),流速1.0mL/min,柱温40℃,检测波长210nm。结果:CAM与相关物质分离良好,线性范围分别是CAM:60.184~3.0092×106ng(R=0.9990),CDA:2.0072×102~2.0072×105ng(R=1),CDI:2.012~4.024×103ng(R=0.9989)。结论:该方法简便、快速、分离度高,适合于CAM及相关物质的测定。 相似文献
2.
腺嘌呤作为一种重要的化工原料,已广泛应用于医药、有机合成等领域,目前腺嘌呤采用丙二酸二乙酯与甲酰胺缩合反应合成,环境污染较大。为实现腺嘌呤生产的绿色化,同时探索腺苷中C-N断裂的机理,开展了在高温液态水中无催化腺苷水解反应的研究,考察了高温液态水中初始浓度、搅拌速率、温度对腺苷水解的影响,研究了150~190 ℃下腺苷的水解反应动力学,在假设反应为零级反应的情况下拟合得到了各温度的反应速率常数,并得出活化能为174.1 kJ8226;mol-1。实验结果表明,高温水解中腺苷无催化水解制备腺嘌呤是可行的,而且产率较高。 相似文献
3.
高温液态水中甜高粱渣半纤维素水解及其机理 总被引:1,自引:0,他引:1
为了回收甜高粱渣中的半纤维素衍生糖并了解其水解机理,在自行设计的Flowthrough反应器中对甜高粱渣进行了高温液态水水解,分别考察了不同反应温度和反应液流量下水解液中产物的生成情况。研究表明,相对葡萄糖和阿拉伯糖而言,木糖的生成受反应温度和反应液流量影响更大。温度高于195 ℃时糖降解加剧,总木糖浓度不断降低;低流量(5 ml?min-1)条件下生成的木糖不能被及时排出而进一步降解。通过产物分析可知,甜高粱渣半纤维素中含有典型的O-乙酰基-4-O-甲基葡萄糖醛酸基阿拉伯糖基木聚糖结构,木糖、葡萄糖、阿拉伯糖、各种低聚糖、乙酸和葡萄糖醛酸等是半纤维素水解的直接产物,糠醛和5-羟甲基糠醛等是糖类的降解产物, 甲酸等小分子酸是它们的进一步降解产物。 相似文献
4.
5.
6.
为了开发性能优异的新型二硝酰胺含能离子盐,采用3, 5-二氨基-1, 2, 4-三唑、硫酸和二硝酰胺铵为原料合成3,5-二氨基-1,2,4-三唑二硝酰胺盐(DATrZDN),并通过红外光谱、核磁共振和元素分析对其结构进行了表征。培养了DATrZDN的单晶并通过X射线衍射仪测定了晶体结构,结果表明其晶体为单斜晶系,空间群为P2(1)/n,晶胞参数为:a=1.332 0(4) nm,b=1.759 3(6) nm,c=1.422 9(4) nm,β=107.524(5)°。采用Gaussian 09程序和Kamlet-Jacobs爆轰方程分别计算了DATrZDN生成热和爆轰性能,生成焓为-164.7 kJ×mol~(-1),爆速8.404 km×s~(-1),爆压31.36 GPa,爆热5275 kJ×kg~(-1)。利用差示扫描量热法和热重分析法考察了DATrZDN的热性能,熔点为163.2℃,热分解温峰为188.6℃,热稳定性较好。 相似文献
7.
8.
9.
10.
稀硫酸催化水解稻草秸秆半纤维素的研究 总被引:1,自引:0,他引:1
对稀硫酸催化水解稻草秸秆半纤维素进行了研究.考察了固液比、稀硫酸质量分数、反应温度、反应时间对半纤维素水解的影响.采用正交实验法,以总还原糖含量为考察指标,对实验结果进行直观和方差分析,探讨稀硫酸催化水解半纤维素的最优反应条件.结果表明,稀硫酸催化水解稻草秸秆半纤维素以固液比(质量体积比)1:10、稀硫酸质量分数25%、反应温度95℃、反应3h为最优条件,在此条件下,10g稻草秸秆粉末水解得到总还原糖2.704g,总还原糖收率达94.9%. 相似文献
11.
12.
13.
研究了中低温稀酸预处理对皇竹草化学组成变化、纤维素酶水解得率与总糖得率的影响,并采用扫描电镜(SEM)对皇竹草纤维结构变化进行了分析.结果表明,随着硫酸浓度的增大、温度的升高和时间的延长,半纤维素含量大幅度降低,且预处理后纤维素酶水解得率也逐渐增大.较好的预处理条件为100 g皇竹草原料,在固液比1:5(g:mL)条件下,用质量分数4.0%硫酸在温度110 ℃下,经过8 h预处理后,纤维素保留率为87.48%,半纤维素水解率为93.68%,所得固体渣经纤维素酶水解72 h后得率为86.3%(纤维素酶用量40 FPIU/g,以纤维素质量计),100 g原料可得到总糖量为54.53 g.预处理后皇竹草纤维表面和细胞壁受到破坏,表面积增大,有利于纤维素酶水解作用的进行. 相似文献
14.
高温高压水中乙酸苯酯无催化水解反应动力学 总被引:3,自引:0,他引:3
测定了乙酸苯酯在高温高压水中(压力15MPa,温度152-216℃)的水解反应动力学数据。结果表明在无任何外加催化剂的情况下,乙酸苯酯能够顺利进行水解反应。随温度升高,反应速率迅速增大,选择性从不足50%提高到80%以上。拟合得到反应活化能为67.77kJ/mol。 相似文献
15.
Degradation Kinetics of Xylose and Glucose in Hydrolysate Containing Dilute Sulfuric Acid 总被引:3,自引:0,他引:3
In preparation of fuel alcohol from biomass as feedstock, hydrolysis with dilute acid as catalyst is one way to produce fermentable saccharide, xylose and glucose. However, the acid is also the catalyst in degradation of xylose and glucose and the yield of sacchride is dependent on the kinetic behaviors of saccharide. The degradation kinetics of xylose and glucose in the hydrolysate was investigated under the conventional process conditions of hydrogen ion concentration from 0.05 to 0.2 mol/L and temperature from 150 to 200℃. With a numerical calculation method, the kinetic parameters were estimated, and the activation energy of xylose and glucose in the degradation reaction was obtained. The kinetic equations correlating the effect of hydrogen ion concentration on the rate constants of degradation reaction were established. Comparison between the calculated results from the equations and experimental ones proved that the established kinetic model could satisfactorily predict the degradation behavior of xylose and glucose in the acidic hydrolysate. 相似文献
16.
17.
18.
Corn stover was separated into four derived streams: ethanol extractives (EE), hot water extractives (HWE), extracted cellulose, and extracted hemicelluloses. They were separately treated with 0.75% dilute sulfuric acid at 180°C for 40 minutes. Over 100 degradation products were separated and identified using gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC). These products contained compounds from several chemical classes, including sugars, aromatics, carboxylic acids, furans, alcohols, aldehydes, and cyclenes. Itaconic acid, succinic acid, fumaric acid, azelaic acid, DL-isoborneol, and 3-methyl-2-furoic acid were detected in the dilute sulfuric acid pretreated corn stover for the first time. Potential microbial fermentation inhibitors and valuable chemical building blocks were evaluated. In an effort to identify and develop inhibitors which are useful for controlling and improving the lignocellulosic biorefinery process, how they originated from the corn stover constituents was examined. 相似文献