不同方法分析十大功劳中生物碱类成分的比较

比较紫外分光光度法和HPLC法分析不同产地十大功劳药材中生物碱类成分的差异。通过高效液相色谱法测量药根碱、小檗碱、巴马汀含量,以三者含量之和为总生物碱含量。并用紫外分光光度法测量总生物碱含量,以小檗碱为对照,测定波长为345 nm。最后两种方法测定结果中,15个样品中不合格的有2个,紫外分光光度法测定结果低于液相色谱的有3个。十大功劳药材质量评价仍应选择HPLC法。     

亚单位流感疫苗中裂解剂壬苯醇醚-9含量两种检测方法的比较

目的比较高效液相色谱法(HPLC)和紫外分光光度法检测亚单位流感疫苗中裂解剂壬苯醇醚-9含量的效果。方法分别采用HPLC法和紫外分光度法检测亚单位流感疫苗中间体和成品中壬苯醇醚-9的含量,并取中间体进行SDS-PAGE分析。结果紫外分光光度法测定亚单位流感疫苗成品和中间体的壬苯醇醚-9含量比HPLC法高10%以上,测定中间体3壬苯醇醚-9含量的结果差异更显著;SDS-PAGE分析显示中间体1、2、3的核蛋白(NP)含量差异显著,大多数存在于中间体3中。结论 HPLC法可代替紫外分光光度法检测亚单位流感疫苗中裂解剂壬苯醇醚-9的含量。     

两种方法测定地表水中叶绿素a的比较

比较了分光光度法和高效液相色谱(HPLC)法测定地表水中叶绿素a的结果。研究表明:两种方法的精密度无显著差异;叶绿素a标准样品测定结果也无显著差异;在测定地表水样品时,分光光度法测定结果高于HPLC法,差异主要由664 nm波长下有较强吸收的物质造成。分光光度法测定结果偏高但操作简单,HPLC法测定结果精准但操作复杂,分光光度法在水质监测工作中更加具有优势。     

露水草提取物β-蜕皮激素含量分析

采用紫外分光光度法并结合HPLC面积归一化法,测定了露水草提取物中β-蜕皮激素的含量。用紫外分光光度法测定的含量,乘以HPLC面积归一化法中的面积百分比,测定了4个露水草提取物中β-蜕皮激素样品的含量。结果表明,本方法测定得到的4个样品的含量分别为45.42%,50.09%,63.18%,52.85%;与高效液相色谱法分析结果(45.72%,50.32%,63.38%,53.11%)相比,相对误差均小于1%。该方法分析准确,简单易行,适用于测定露水草提取物中β-蜕皮激素含量。     

高效液相色谱法和紫外分光光度法测定二硫氰基甲烷含量的比较研究

比较了高效液相色谱法(HPLC)和紫外分光光度法(UV)测定二硫氰基甲烷含量的结果.结果显示,UV测定二硫氰基甲烷样品含量均值为96.01%,相对标准偏差RSD为0.18%;HPLC法测定同批次样品均值为95.61%,相对标准偏差RSD为O.12%.配对t检验统计结果表明HPLC和UV法的结果没有显著性差异,两种方法均可作为二硫氰基甲烷含量的测定方法.     

紫外分光光度法和高效液相色谱法检测食品塑料包装中荧光增白剂

比较紫外分光光度计法和高效液相色谱法对荧光增白剂的检测。使用氨水处理塑料包装样品,分别使用紫外分光光度计和高效液相色谱检测其中的荧光增白剂,比较两者回收率、精密度和检出限。经统计学分析紫外分光光度计法和高效液相色谱法不是等精密度检测,紫外分光光度计法回收率为95.7%~102.4%,精密度(相对标准偏差)为2.49%,检出限为0.06 mg/kg;高效液相色谱法回收率为98.8%~102.3%,精密度(相对标准偏差)为1.15%,检出限为0.03 mg/kg。紫外分光光度计法和高效液相色谱法都可以满足对塑料中的荧光增白剂进行常规检测的要求,高效液相色谱法的精度更高。     

靛蓝提取物中靛蓝和靛玉红的分析方法比较

以靛膏为原料,采用盐酸酸化、葡萄糖还原和乙酸乙酯提取3种工艺制备靛蓝酸化物、靛蓝还原物和乙酸乙酯提取物。建立高效液相色谱(HPLC)法、紫外可见分光光度(UV)法和双波长紫外分光光度(dW-UV)法,分析3种靛蓝提取物中靛蓝和靛玉红的含量,并以Kolmogorov-Smirnov检验、Bland-Altman偏差图比较和Spearman检验确定3种样品各自最佳分析方法。结果表明：所建立的HPLC法、UV法和dW-UV法简单、准确、灵敏度高、稳定性好和重复性好。3种靛蓝提取物成分含量检测方法均遵从正态分布,两两测定值存在显著差异。UV法更适于分析靛蓝酸化物、靛蓝还原物中靛蓝含量;HPLC法更适于乙酸乙酯提取物中靛蓝、靛玉红含量分析。     

天麻素的含量测定、结构表征和药理活性研究进展

为促进天麻素的进一步研究和开发,以"天麻素""含量测定""结构""药理活性"为关键字检索相关文献,对天麻素的含量测定、结构表征和药理活性进行归纳总结.天麻素的提取方法包括半仿生-酶法、超高效液相色谱法、HPLC法、微波法、紫外分光光度法等,其中HPLC法应用较为广泛.天麻素属于酚苷类化合物,且为氧苷,相对分子质量较小,...     

阿司匹林肠溶片含量测定方法比较

分别采用酸碱滴定法、紫外分光光度法和高效液相色谱法对规格为25 mg阿司匹林肠溶片进行了测定。结果表明:由于辅料的影响,酸碱滴定法测定值严重偏高;紫外分光光度法测定值比较稳定,精密度高,测定值符合要求;高效液相色谱法测定值符合要求,但对仪器精度要求高。结论是酸碱滴定法不适用于小剂量阿司匹林肠溶片含量测定。     

UV法和HPLC法测定合成色素诱惑红的比较

比较检测糖果中合成色素诱惑红的两种方法。用聚酰胺粉吸附提取诱惑红色素,再分别用纸色谱法分离紫外可见分光光度计法测定和反相高效液相色谱法分离测定外标法定量。高效液相色谱法的精密度高于紫外可见分光光度计法,高效液相色谱法的检出限低于紫外可见分光光度计法。测定糖果中合成色素诱惑红含量时,高效液相色谱法优于紫外可见分光光度计法。     

可见与紫外光度法测定沙棘叶中总黄酮的比较

对可见与紫外分光光度法测定沙棘叶中总黄酮的方法进行了比较。可见分光光度法以芦丁为标准品,硝酸铝作显色剂,在510 nm波长下测定;紫外分光光度法以芦丁为标准品,在358 nm波长下测定。结果表明:紫外分光光度法测定沙棘叶中总黄酮相对简便快速,是一种较理想的测定方法。     

中药材中维生素C含量测定方法的对比分析

通过对比分析的方法,确定在不同的中药材中维生素C含量的测定方法。将五味子、枸杞、山楂、大枣等药材进行研究,采用紫外分光光度法、二氯靛酚滴定法和高效液相色谱法3种方法进行维生素C的测定,对测定的过程和结果进行分析,选择最合适的维生素C测定的方法。结果表明,采用高效液相色谱法对维生素C进行测定的准确性最高,滴定法最简单,但是测试的结果不是特别准确,特别在测试颜色较深的样品中误差偏大。紫外分光光度法测定的结果与其他的两种方法比偏高,容易受到杂质的影响。高效液相色谱法在对中药中的维生素C测定中最合适,滴定法的局限性比较多,只能对颜色较浅的样品进行测定,紫外分光光度法在维生素C含量测定中不合适。     

HPLC测定追风苏合丸中橙皮苷的含量

文章建立了HPLC法测定追风苏合丸中橙皮苷的含量。采用Kromasasil C18柱（150mm×4.6mm,5μm）,以甲醇：水：乙酸（40：60：4）为流动相,紫外检测波长为283mm。结果表明,橙皮苷在1.11-5．55μg;范围内呈良好的线性关系（r=0.9998）,橙皮苷平均回收率为97：6％,（n=6）,RSD为1．35％。该方法准确、可靠、重现性好,可适用于追风苏合丸中橙皮苷的含量测定。     

Extraction and HPLC Characterization of Chlorogenic Acid from Tobacco Residuals

Abstract

Chlorogenic acid is a highly valuable natural polyphenol compound used in medicine and industries. Its current commercial sources are from plant extracts of Lonicera japonica Thunb and Eucommia ulmoides Oliver. These sources are limited and expensive. On the other hand, tobacco residuals contain chlorogenic acid and other natural polyphenol compounds. Large quantities of tobacco residuals are produced each year as waste materials from tobacco manufacturing, potentially providing an alternative commercial source of chlorogenic acid and other valuable compounds. In this paper, microwave and ultrasound extractions of chlorogenic acid with mixed solvent were studied. Total polyphenol concentrations in extract solutions obtained with different extraction methods were analyzed with the method of ferrous tartrate and UV‐Vis spectrophotometry and compared. The extraction solutions were also characterized for polyphenol compositions with the method of HPLC. Experimental results indicated that high extract concentrations of chlorogenic acid were obtained with a mixed solvent of acetone and water (1:2 v/v). A total polyphenol concentration of up to 4.87 mg/ml and a chlorogenic acid concentration of up to 2.12 mg/ml were achieved. The application of microwave and ultrasound significantly increased the extract concentrations. The extraction time needed was also much reduced. HPLC analysis indicated that acetone water mixed solvent extraction achieved much higher relative concentrations of chlorogenic acid to other compounds in the extract solutions. These results indicted that fast and effective extraction of chlorogenic acid from tobacco residuals were achieved.     

紫外法和皮粉法测定塔拉单宁含量的对比研究

分别采用紫外法和皮粉法对5种不同含量的塔拉单宁进行对比研究,并利用SPSS软件对单宁含量测定结果进行显著性检验,结果表明：高纯度塔拉单宁(93%)分别用紫外法和皮粉法测定单宁含量时实验结果并未显著差异(P>0.05),而4种纯度为60%左右塔拉单宁的实验结果均具有显著性差异(P<0.05),皮粉法测得的单宁含量均比用紫外法测得的结果高,差值约为1.5%～2.0%,并由此计算出紫外法测定塔拉单宁含量计算公式中的矫正常数p为1.03。紫外-可见吸收光谱与HPLC分析结果表明：塔拉单宁与五倍子单宁的最大吸收峰均为276 nm,同质量浓度下塔拉单宁的吸收峰强度高于五倍子单宁,塔拉单宁成分出峰时间主要在20～40 min,五倍子单宁主要在30～45 min。     

A rapid microwave‐assisted solvent extraction method for assessment of stabilizer concentration in crosslinked polydimethylsiloxane

Crosslinked polydimethylsiloxanes were prepared containing 0.05 to 0.2 wt % of either a phenolic antioxidant (Irganox® 1010) or a hindered amine stabilizer (Tinuvin® 144). The stabilizer concentration was assessed by HPLC and UV‐Vis spectroscopy of Soxhlet and microwave‐assisted solvent extracts. Almost complete recovery of stabilizer was achieved with Soxhlet extraction. High stabilizer recovery was achieved when acetone was used as the solvent in the microwave‐assisted extraction. HPLC was shown to be an efficient method for determining the concentration of Irganox 1010. For Tinuvin 144 the selectivity of both UV‐Vis spectroscopy and HPLC was poor, leading to imprecise evaluation of the antioxidant concentration. The loss of stabilizer by migration from polymer to hot water (75 and 95°C) was monitored for the systems stabilized with Irganox 1010 and the diffusion coefficient of the antioxidant in the polymer was determined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2185–2192, 2004     

Eggplant as an appreciable bio-template for green synthesis of NiO nanoparticles: Study of physical and photocatalytic properties

In this study, we described a green, sustainable, and feasible method for synthesizing 5 nm NiO nanoparticles. Eggplant skin was chosen as an appropriate bio-template with a high potential to induce its structure into the desired metal oxide. Two approaches were used and compared to synthesize NiO bio-template: hydrothermal and sol-gel. The morphology and physical properties of the obtained NiO nanoparticles were evaluated using FESEM, TEM, XRD, BET, FT-IR, TGA, and UV–Vis analyses. All these methods confirm that the hydrothermal method is a better approach for synthesizing NiO bio-template nanoparticles than the sol-gel method. UV–Vis analysis revealed that the NiO nanoparticles produced by the hydrothermal method have a low bandgap of 2.88 eV, which is a key factor for photocatalytic applications.     

S–N Co-Doped TiO2 Photocatalysts with Visible-Light Activity Prepared by Sol–Gel Method

S–N co-doped anatase nanosized TiO₂ photocatalyst was successfully prepared by simple sol–gel method. The samples were characterized by XRD, XPS, UV–Vis. From the results of UV–Vis, a red shift of the absorption edge was brought out owing to the S and N codoping. XPS and UV–Vis studies revealed that N and S were in situ codoped in the lattice of TiO₂ and the absorbance in visible light region decreased with the calcination temperature increased. The photocatalytic activity was evaluated by the photocatalytic oxidation of penicillin solution under visible light irradiation. The results show that visible-light induced photocatalytic activities of the as-prepared TiO₂ powders were improved by S–N copoing. The high activity of S–N co-doped TiO₂ can be related to the results of the synergetic effects of strong absorption in the UV–Vis region, red shift in adsorption edge.