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超声提取-高效液相色谱法测定烟草中烟碱含量 总被引:4,自引:0,他引:4
确定了制备烟碱分析样品的超声波提取条件:0.4% NaOH溶液为溶剂,液固比40:1(mL·g-1),提取时间4 h.确定了高效液相色谱法检测烟碱含量的条件为Kromasil C18色谱柱(250 mm×4.6 mm,5 μm),检测波长259 nm,检测温度35 ℃,流动相CH3OH/0.02 mol·L-1磷酸盐缓冲溶液(V/V)为60/40,流速1.0 mL·min-1,进样量10 μL.平均加样回收率98.8%,相对标准偏差1.2%.结果表明超声提取-高效液相色谱法是一种准确度高,速度快的测定烟草中烟碱含量的检测方法. 相似文献
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从红景天中提取了红景天甙。采用高效液相色谱法测定红景天甙的含量,通过正交试验筛选出最佳工艺为:8倍量70%乙醇,提取3次,每次2h。 相似文献
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建立水蒸汽蒸馏法提取-高效液相色谱法测定橡胶中甲醛的方法。橡胶剪碎后,用蒸馏水浸泡24 h,然后采用水蒸汽蒸馏法提取,高效液相色谱法进行测定。考察了蒸馏时间对甲醛提取效果的影响,优化了高效液相色谱法测定的条件。水蒸汽蒸馏提取30 min可完全提取出橡胶中的甲醛,用V(乙腈)∶V(水)=60∶40为流动相、流速设为0.8 m L/min、检测波长设为350 nm的高效液相色谱条件进行测定,用该方法检测超市、批发市场及橡胶生产厂家的橡胶样品,测定得到的甲醛含量分别为27.2、28.4和30.2 mg/kg。添加8~80 mg/kg的甲醛标准液回收率为85.4%~105.2%,相对标准偏差为1.7%~3.4%。水蒸汽蒸馏法提取-高效液相色谱法测定橡胶中甲醛,具有样品预处理简单、灵敏度高、分析时间短等优点,适用于橡胶中甲醛的测定。 相似文献
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HPLC法测定不同产地中药石韦的绿原酸含量 总被引:1,自引:0,他引:1
目的:建立高效液相色谱法测定中药石韦中绿原酸含量的方法.方法:采用高效液相色谱法.色谱条件:色谱柱为C18柱;流动相为乙腈-0.4%磷酸溶液(10∶90);检测波长为327nm;流速为1.0ml/min;柱温:室温.结果:绿原酸在0.07169~1.4338μg范围内线性关系良好,回归方程为:y=3110737.9x-6670.4,(r=0.999 9),平均回收率为98.7%(RsD=1.5%).结论:本法简单、准确、稳定,可用于石韦药材质量评价. 相似文献
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[目的]建立高效液相色谱测定烟筋中的烟碱含量。[方法]用4%Na OH溶液提取,正己烷和20%H2SO4溶液萃取,Ba(OH)2沉淀的方法提取烟筋中烟碱;选用Hypersil BDS-C18色谱柱,流动相为甲醇-水(0.02 mol磷酸二氢钾加0.52%三乙胺,用磷酸调整p H值为6.5)(体积比60颐40),检测波长260 nm,流速1.0 m L/min,柱温40℃,进样量10滋L。[结果]烟碱质量浓度在100~1 000 mg/L时,线性关系良好;添加水平为8.00~32.00 mg时,回收率为98.37%~99.03%,RSD为0.65%。[结论]该方法能准确快速检测烟筋中烟碱的含量。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献
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In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997 相似文献
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徐善明 《现代塑料加工应用》2008,20(5)
应用管理学和市场营销学的基本原理和方法,深入分析我国聚丙烯工业的内部和外部环境、市场状况以及加入WTO后所面临的机遇与挑战.在此基础上,应用SWTO(态势分析法),确认出主要的优势和劣势、机会和威胁,对我国聚丙烯工业的国际竞争力进行结构化的综合分析. 相似文献
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