紫外分光光度法测定水红花子中槲皮素的含量

目的采用紫外分光光度法测定水红花子中槲皮素的含量。方法在25℃、最大吸收波长为370 nm处测吸光度。结果此法线性范围0.004~0.011 9 g/L内,r=0.999 2,平均回收率为96.55%,RSD为0.78%(n=5)。结论用此方法可测量水红花子中槲皮素的含量。方法简便,灵敏度和准确度较高,结果满意。     

醋柳黄酮和银杏叶提取物含量测定的差异性

目的:分别以槲皮素、异鼠李素为对照品测定醋柳黄酮与银杏叶提取物中总黄酮含量,研究是否可以用槲皮素代替异鼠李素作对照品。方法:采用分光光度法测定醋柳黄酮与银杏叶提取物中总黄酮含量。结果:以槲皮素折合,醋柳黄酮中总黄酮含量为8.90%,银杏提取物中总黄酮为4.41%;以异鼠李素折合,醋柳黄酮中总黄酮含量为16.80%,银杏提取物中总黄酮含量为8.25%。结论:分别以槲皮素、异鼠李素为对照品测得同一样品,总黄酮含量差异很大,不能简单用槲皮素代替异鼠李素进行样品总黄酮的含量测定。     

甲硝唑混悬液的研制及临床应用

采用控制结晶法研制出甲硝唑混悬液并对其质量控制方法及稳定性进行了研究。因该制剂结晶极细微致吸收速率增大，又因甘油为分散相，滞留患部时间长，用于口腔疾病可延长药物作用时间。临床观察疗效满意。     

偏最小二乘紫外分光光度法测定土霉素生物效价

土霉素的含量测定,各国标准仍主要采用微生物检定法。该法虽然能反映其生物效价,但准确度不高,费时。长期以来人们试图寻求理化方法来取代微生物法。紫外分光光度法简便、快速,广泛地运用于药物分析     

Determination of some psychotropic phenothiazine drugs by charge-transfer complexation reaction with chloranilic acid

A spectrophotometric method is described for the determination of four commonly used psychotropic phenothiazine drugs. The method is based on the measurement of the intensely coloured charge-transfer complex formed by the interaction of these drugs as n-electron donors with chloranilic acid as the pi-acceptor. The coloured species measured exhibits maximum absorption at 535 nm. The molar-combining ratio and optimum assay conditions are reported. Beer's law is obeyed over the range, 25-250 microg ml(-1) with apparent molar absorptivity in the range, 0.93 x 10(3)-1.45 x 10(3) l mol(-1) cm(-1). The limits of detection and quantification are reported. The proposed method was applied to the determination of these psychotropics in pharmaceutical formulations and the results demonstrated that the method is equally accurate, precise and reproducible as the official methods. The validity of method was established by recovery studies via standard-addition technique with satisfactory results.     

Application of ninhydrin to spectrophotometric determination of famotidine in drug formulations

A simple and fast spectrophotometric procedure has been developed for the determination of famotidine. The method is based on the interaction of ninhydrin with primary amines present in the famotidine. This reaction produces a blue coloured product which absorbed maximally at 590 nm. The effects of variables such as reagent concentration and reaction time were investigated to optimize the procedure. Beer's law was obeyed in the concentration range of 5-30 microg ml(-1) with molar absorptivity of 6.99 x 10(3) l M(-1) cm(-1). The results were validated statistically. The proposed method has been applied to the determination of famotidine in tablets with satisfactory results.     

Sensitive spectrophotometric determination of amlodipine and felodipine using iron(III) and ferricyanide

A simple, accurate, sensitive and economical procedure for the estimation of amlodipine besylate and felodipine, both in pure form and in formulations has been developed. The method is based on the reduction of iron(III) by the studied drugs in acid medium and subsequent interaction of iron(II) with ferricyanide to form Prussian blue. The product exhibits absorption maximum at 760 nm in both cases. Beer's law is obeyed in the concentration ranges 5.0-15.0 and 1.5-5.0 microg/ml, for amlodipine and felodipine, respectively. The molar absorptivities are 1.76 x 10(4) and 4.24 x 10(4) l/mol cm. The corresponding Sandell sensitivities are 23.18 and 9.06 ng/cm(2). The limits of detection as well as quantification are reported. Seven replicate analyses of solutions containing three different concentrations of each drug were carried out and the percent error and the RSD values have been reported. The proposed method was applied to the determination of these drugs in pharmaceutical formulations and the results demonstrate that the method is equally accurate and precise as the official methods as found from the t- and F-values. The reliability of the method was established by recovery studies using standard-addition technique.     

微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质

目的:建立简便、准确、绿色的食品中蛋白质的批量测定方法。方法:利用微波溶样技术处理样品,并与乙酰丙酮和甲醛显色定量。结果:微波消解-乙酰丙酮甲醛分光光度法与国标凯氏定氮法相比测定结果差异无显著性,该方法线性范围在5~100μg/10 m l,相关系数r=0.9997,检出限为0.546μg/10 m l,相对标准偏差(RSD)为1.29%~2.21%,加标回收率93.3%~103%。结论:微波消解-乙酰丙酮甲醛分光光度法测定食品中蛋白质方法简便、试剂用量少且环保,方法具有较好的准确度和精密度,适合于批量蛋白质样品的测定。     

顺序注射分光光度法测定左氧氟沙星、氧氟沙星和洛美沙星

本文基于左氧氟沙星、氧氟沙星和洛美沙星分别与Fe(Ⅲ)作用形成黄色络合物的现象,建立了简单、快速测定药物中左氧氟沙星、氧氟沙星和洛美沙星的顺序注射分光光度新方法。讨论了物理因素和化学因素对方法灵敏度的影响。测定左氧氟沙星、氧氟沙星和洛美沙星的工作曲线的线性范围均为10~250μg/ml。采用摩尔比法和连续变换法测定络合物的组成,Fe(Ⅲ)与药物的组成比为1∶2。将方法用于药物中左氧氟沙星、氧氟沙星和洛美沙星的测定,并与参考方法进行了对照。     

RP-HPLC法测定罗红霉素片中罗红霉素的含量

目的建立罗红霉素片含量测定的高效液相色谱法,并与微生物检定法、紫外分光光度法的测定结果进行比较。方法采用Agilent-C18色谱柱（4.6 mm×250 mm,5μm）;0.067 mol·L^-1磷酸二氢铵（三乙胺调节pH6.5）-乙腈（3∶2）,加入1%的三乙胺,用磷酸调节pH7.2为流动相;流速1.0 ml·min^-1;检测波长211 nm;柱温30℃。结果罗红霉素在2.14～42.80 mg·L^-1的浓度范围内有良好的线性关系（r=0.999 9）,平均回收率为97.8%,RSD为0.78%（n=5）。结论三种含量测定方法的结果相近,均可用于罗红霉素片的含量测定。