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《广东化工》2021,48(17)
对黄精炮制过程中黄精多糖、总黄酮、总酚和薯蓣皂苷四种成分的含量变化规律进行了探究。前三种成分采用60%乙醇提取黄精的有效成分,并用紫外分光光度计测定各成分的含量;薯蓣皂苷采用甲醇提取,高效液相色谱法(HPLC)测定其含量。实验结果显示,炮制过程中,黄精多糖的含量逐渐降低,于第六蒸达到最低值312mg/g;总黄酮和总酚的含量随炮制时间的增加而升高,均在第七蒸达到最高值,分别为4582μg/g,6979μg/g;薯蓣皂苷的含量随炮制时间的增加而逐渐降低,从第六蒸起含量基本保持稳定,约为73μg/g。多花黄精中四种成分的含量随着炮制时间的增加呈现不同变化,研究结果为黄精饮片的质量标准提供依据,并为确定黄精饮片炮制的最佳阶段提供参考。 相似文献
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建立气相色谱法测定桂枝茯苓胶囊中丹皮酚含量的方法。色谱柱为DB-624(0.53 mm×30 m×3μm);氢火焰离子化检测器(FID);色谱条件:采用程序升温,110→170→230℃,升温速率10℃/min;进样口温度250℃;检测器温度300℃;流速4 m L/min;分流比1∶1。按外标法测定丹皮酚的含量。结果表明:丹皮酚在20~200μg/m L浓度范围内与峰面积线性关系良好(r=0.9996),平均加标回收率为108.70%(RSD%=1.38,n=3)。本方法准确、可靠、快速、简便,可用于测定桂枝茯苓胶囊中丹皮酚的含量。 相似文献
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目的探讨厄贝沙坦氢氯噻嗪片治疗原发性高血压的临床疗效与安全性。方法选择86例原发性高血压患者,每日口服厄贝沙坦氢氯噻嗪片(含厄贝沙坦150mg氢氯噻嗪12.5mg),疗程4周,比较治疗前后患者血压变化情况,并观察总体疗效与不良反应情况。结果治疗组43例患者经厄贝沙坦氢氯噻嗪片治疗后,显效占53.49%,有效占34.88%,无效占11.63%,总有效率为88.37%。43例患者的收缩压和舒张压均明显低于治疗前。结论厄贝沙坦治疗原发性高血压相对安全、有效,值得推广应用。 相似文献
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三种测定水果中维生素C含量方法的比较 总被引:2,自引:0,他引:2
以市面上常见的11种新鲜水果为测试对象,实验分别采用紫外分光光度法、2,6-二氯靛酚正滴定法和2,6-二氯靛酚反滴定法对水果中维生素C的含量进行了测定以比较三种测定方法的差异。测定结果表明测定芒果和血橙样品的维生素C含量时2,6-二氯靛酚正滴定法和2,6-二氯靛酚反滴定法有显著性差异,测定特小凤西瓜的维生素C含量时2,6-二氯靛酚正滴定法和2,6-二氯靛酚反滴定法有非常显著差异,在其它测定的水果样品中两种滴定方法的测定结果无显著性差异。采用紫外分光光度法测定维生素C含量时在10~120μg/m L范围内吸光度与浓度之间呈现良好线性关系。紫外分光光度法在测定水果中总维生素C含量时测定结果稳定,不易受样品提取液颜色的影响;对于无颜色或颜色较浅的样品,2,6-二氯靛酚滴定法是一种测定还原型维生素C含量简便易行的方法。 相似文献
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通过对丹皮酚紫外吸收光谱的分析,选择较佳检测波长和适当的流动相对洗涤剂进行分离,测定洗涤剂中的丹皮酚含量。通过测定重复性、精密度、回收率,最终建立并验证了高效液相色谱法测定洗涤剂中丹皮酚含量的方法。实验结果表明,标准溶液在0.1~20μg·mL~(-1)线性相关,回收率为99%~101%。 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 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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The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure. 相似文献
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以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献