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泼尼松龙磷酸钠(prednisolone sodium phosphate,PPNa)为11β,17α,21-三羟基孕甾-1,4-二烯-3,20-二酮-21-磷酸酯二钠盐。目前国内还未上市销售,也无其分析方法的报道,但有对醋酸泼尼松龙进行分析的报道。美国药典26对其提取分离后用紫外分光光度法检测PPNa中的游离泼尼松龙,但对其注射液未做有关物质的测定;英国药典2002年版采用高效液相色谱法检测PPNa原料中的有关物质,流动相系统复杂。本文建立的反相高效液相色谱法。流动相系统简单。能将供试品中的主峰与杂质峰完全分离,方法快速灵敏、准确度高、重复性好,可用于PPNa原料药及其注射剂的含量测定和有关物质的测定。 相似文献
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采用顶空固相微萃取-毛细管气相色谱联用技术测定了洗涤制品中的1,4-二氧杂环己烷.使用自制的萃取头(苯乙烯-丙烯酸乙酯共聚物与PEG20M复合)于顶空平衡温度80℃下萃取样品40 min.萃取物用内壁涂有SE-30固定液的石英毛细管柱分离,外标法定量.1,4-二氧杂环己烷含量为0.35~120 μg/g时,其峰面积与含量呈良好的线性关系(r=0.999 8);回收率为98.7%~102%;相对标准偏差(n=5)为9.33%. 相似文献
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本文报道了一种用紫外分光光度法测定丙二酸亚异丙酯类化合物中烯醇含量的方法。用该法测得的烯醇含量与弛豫测定法所得到的结果近似。此外,应用该法还测定了三种α-烃基取代丙二酸亚异丙酯的烯醇含量。 相似文献
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采用魔角旋转固体核磁碳谱法(MAS–~(13)CNMR)测定硫化丁苯橡胶中的苯乙烯含量。通过固体核磁碳谱解析,对丁苯橡胶中苯乙烯、1,2-乙烯基、1,4-丁二烯的特征峰进行归属分析,以固体核磁外标法定量。对已知苯乙烯含量的标准样品进行测定,绘制校正曲线,结果显示理论苯乙烯含量与固体核磁法计算结果成良好的线性关系,线性相关系数(r~2)为0.97。经标准曲线校正后的苯乙烯含量接近于真实值,计算结果的相对误差小于5%,测定结果的相对标准偏差为0.31%(n=6)。该方法适用于单一胶种的硫化丁苯橡胶中苯乙烯含量的检测。 相似文献
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利用手持技术改进测定乙醇分子结构实验 总被引:1,自引:0,他引:1
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。 相似文献
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Mustafa R. Ibrahim Zacharia A. Fataftah Paul von Ragu Schleyer Peter D. Stout 《Journal of computational chemistry》1987,8(8):1131-1138
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases. 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1989,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988. 相似文献
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V. I. Bol'shakova L. I. Demenkova É. N. Shmidt V. A. Pentegova 《Chemistry of Natural Compounds》1988,24(6):691-694
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae. 相似文献
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由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。 相似文献