分光光度法测定纯稀土金属中微量硅

本文研究了纯稀土金属中微量硅的钼蓝测定方法,在ｐＨ＝１．２时,加入酒石酸破坏磷钼酸以消除磷的干扰,以抗坏血酸为还原剂,在λ＝８１０ｎｍ处,测定吸光度,测定浓度范围为０．０００５％￣０．０１５％。     

Spectrophotometric Determination of Enalapril Maleate and Ramipril in Dosage Forms

Three sensitive and accurate spectrophotometric methods have been developed for the assay of enalapril maleate and ramipril, each in its dosage forms. These methods depend on the reaction of the drugs with p-chloranilic acid, the reaction with picric acid, and the ion-pair salt formation with bromocresol green. The proposed methods have been applied to the analysis of these drugs in their commercial tablets. The results obtained were precise and accurate.     

Spectrophotometric Methods for the Determination of Chloramphenicol,Dexamethasone Sodium Phosphate,and Tetrahydrozoline HCl in their Pure and Ophthalmic Dosage Forms

Journal of Applied Spectroscopy - Chloramphenicol (CHL), dexamethasone sodium phosphate (DSP), and tetrahydrozoline HCl (THZ) are co-formulated for conjunctivitis treatment. The ternary mixture...     

Spectrophotometric and Spectrofluorimetric Methods for the Determination of Terazosin in Dosage Forms

Five simple and accurate methods are presented for the determination of terazosin (TZ) in tablets. These methods are based on: the direct measurements of the first and second derivative spectra of samples (A), the reaction of TZ with chloranil (CH) in aqueous solution of pH 9 to give an intense yellow color measured at 340 nm (B), the reaction of the drug with mercurochrome (MER) in aqueous alkaline medium to give an intense red color measured at 543 nm (C), the formation of an ion-pair salt between the drug and bromocresol purple (BCP) with subsequent absorbance measurements at 412 nm (D), and a sensitive fluorimetric method (E). The latter method was extended to determine TZ in presence of its degradation products.     

Micelle-Enhanced Spectrofluorimetric Method for Determination of Cholesterol-Reducing Drug Ezetimibe in Dosage Forms

A simple and sensitive spectrofluorimetric method was developed for the determination of ezetimibe in its pharmaceutical formulations. The proposed method is based on investigation of the fluorescence spectral behavior of ezetimibe in sodium dodecyl sulfate (SDS) micellar system. In aqueous solution of acetate buffer pH 5.0, the fluorescence intensity of ezetimibe was greatly enhanced, 200% enhancement, in the presence of SDS. The fluorescence intensity of ezetimibe was measured at 380 nm after excitation at 268 nm. The fluorescence-concentration plot was rectilinear over the range of 0.03–3.0 μg/mL with lower detection limit of 3.08 × 10⁻³ μg/mL. The method was successfully applied to the analysis of ezetimibe in its commercial tablets; the results were in good agreement with those obtained with the reported method. The application of the proposed method was extended to the stability studies of ezetimibe after exposure to different forced degradation conditions, such as acidic, alkaline, photo and oxidative conditions, according to ICH guidelines.     

Spectrofluorimetric Determination of Terbinafine Hydrochloride and Linezolid in their Dosage Forms and Human Plasma

A highly sensitive, simple and rapid spectrofluorimetric method was developed for the determination of Terbinafine HCl (TRH) and linezolid (LNZ) in their pharmaceutical formulations. The proposed method is based on measuring the native fluorescence of the studied drugs in water at 336 nm after excitation at 275 nm for TRH and 375 nm after excitation at 254 nm for LNZ. The fluorescence–concentration plots were rectilinear over the range of 0.02–0.15 μg/mL for TRH and 0.5–5.0 μg/mL for LNZ. With lower detection limits of 3.0 and 110.0 ng/mL and a lower quantification limit of 9.0 and 320.0 ng/mL for TRH and LNZ, respectively. The method was successfully applied to the analysis of TRH in its commercial tablets, cream, gel and spray formulations and the results were in good agreement with those obtained with the official method. In addition the method was also applied to the analysis of LNZ in its capsule and I.V solution and the results were in good agreement with those obtained with the comparison method. The effect of sensitizers was studied. The method was extended to the determination of the studied drugs in spiked human plasma and the results were satisfactory.     

分光光度法测定蒙药黑冰片中微量钼

苯基荧光酮(苯芴酮)-CTMAB分光光度法测定黑冰片中钼的含量.实验结果表明,钼在0-15.029μg/mL范围内有良好的线性关系,其回归方程为:A=0.981714C585-0.157942(r=0.976).回收率为99.8%.RSD为0.948%.     

分光光度法测定食盐中的碘

采用分光光度法对食盐中碘含量进行定量分析.对反应条件进行试验及优化,得最佳测定条件为:测定波长565nm,0.5mol/L盐酸2.00mL、3%双氧水3.00mL、10g/L淀粉1.00mL,显色时间10min.在此条件下测得碘含量为29.32mg/kg,符合国家标准.本方法操作简便,可靠,重现性好,专属性强,具有广泛...     

分光光度法快速测定纺织品中的三氯生

以二氯甲烷为提取溶剂,超声提取纺织品中的三氯生,然后在282nm波长下测定提取液的吸光度,建立了一种测定纺织品中三氯生的分光光度法,并对方法的线性关系、精密度、回收率、检出限等进行了研究.三氯生浓度在0.2-80mg/L范围内呈良好线性关系,线性相关系数为0.9998,回收率为91.15%-103.51%,相对标准偏差...     

药物中安乃近含量的光度法测定

本文基于安乃近有还原性，在酸性介质中可将Fe^3 还原为Fe^2 ，邻二磷菲能与所生成的Fe^2 显色生成红色络合物，最大吸收峰在510nm处，采用邻二氮菲光度法测定了药物中的安乃近含量，结果令人满意。     

分光光度法测定发酵液中果糖的含量

针对微生物转化发酵液体系的特征 ,用分光光度法测定其中果糖的含量。校准曲线回归方程为 y=2 6 .2 3x 0 .0 0 7,相关系数为 0 .9991 ;1 0倍量葡萄糖和 1 0倍量甘露醇的存在对果糖测定基本无干扰 ;发酵液中果糖测定的加标回收率为 99.1 %— 99.8%。     

二极管阵列紫外分光光度法测定西埃斯

利用紫外分光光度法对西埃斯进行检测,在0.2072-10.36μg/mL浓度范围内线性关系良好(R2=0.9990),检出限为0.0518μg/mL,相对标准偏差(RSD)为0.82％,回收率在99.3％-100.1％之间.本法操作简便,准确,能较好的应用于气溶胶中痕量西埃斯的测定.     

茚三酮分光光度法测定头孢克洛

研究了头孢克洛与茚三酮之间的显色反应,确定了反应条件,建立了一种简便而灵敏的测定头孢克洛的分光光度法.实验表明,头孢克洛与茚三酮在pH为5.4的水溶液中,沸水浴1h可以反应完全,产物的最大吸收波长λmax=565nm,表观摩尔吸光系数为4.53×103L·mol-1·cm-1.头孢克洛质量浓度在10-90mg·L-1范围内服从比耳定律,相关系数为0.9993,测定结果的相对标准偏差为1.16％(n=6),回收率在99.0％以上.本方法用于测定制剂中头孢克洛的含量结果与药典法相符.     

分光光度法测定阿奇霉素的改进

通过对阿奇霉素显色反应过程中硫酸浓度,反应时间,反应温度的研究,优化了分光光度法测定阿奇霉素含量的方法。结果表明,阿奇霉素在11.26—45.03mg.L-1浓度范围内,显色溶液在482nm处吸光度与其浓度具有良好的线性关系,线性回归方程为A=0.0172C（mg.L-1）＋0.0504,平均回收率为99.1%（n=9）。该方法简单,比传统光度法更灵敏、准确,适合于阿奇霉素含量的快速测定。     

乙酰螺旋霉素的间接光度法测定

本文建立了一种乙酰螺旋霉素的新的分析方法，乙酰螺旋霉素在盐酸、磷酸混合液中显棕色，该溶液在470nm处有最大吸收，可用于乙酰螺旋霉素的间接光度法测定。其其线性范围是2.0-50.0mg/mL，相关系数是0.9995，回归方程是y=3.56×10^-3＋1.025C。本法用于乙酰螺旋霉素的实际样品测定，结果令人满意。     

荷移分光光度法测定缬氨酸

用分光光度法研究缬氨酸与7,7,8,8-四氰基对苯醌二甲叉(TCNQ)的荷移反应.确定以pH=9.2的三酸缓冲溶液为介质,在50C的水浴中加热30min,形成稳定的络合物,其λmax=417nm,表观摩尔吸光系数ε=7.8×103L·mol-1·cm-1,在1-9μg/mL的范围内符合比耳定律,回收率在96.7％-102.7％,相对标准偏差小于2.9％.     

分光光度法测定微量铬

在稀硫酸介质中，利用微量Ｆｅ￣（２＋）诱导Ｃｒ（Ⅵ）与甲基橙反应，建立分光光度法测定铬。     

花生中黄酮的荧光分光光度法测定

研究了花生中黄酮的荧光分光光度法测定条件,用芦丁为标准样品,在荧光激发波长λex=265nm,发射波长λem=331nm处测定了花生中黄酮的含量,回归方程为y=5.0775x＋46.716,相关系数r=0.9994,精密度（RSD）为0.28%（n=5）,加标回收率为93.75%—115.00%,该方法用于测定花生中黄酮的含量结果准确。     

分光光度法测定沙棘叶多糖含量

经苯酚-硫酸显色,用分光光度法测定沙棘叶多糖含量。测定波长490nm,葡萄糖含量在10.0—71.0μg/mL范围内与吸光度呈良好的线性关系,r=0.9981,多糖换算因子f为3.271。测得不同月份同一片植株沙棘叶多糖含量分别为:5月份3.39%,7月份3.94%,9月份4.42%,平均回收率为99.07%,RSD为3.22%。