三波长分光光度法研究：Ⅰ.K系数法测定混合三组份

本文提出利用三波长分光光度法测定混合三组份中的单一组份。在适宜的测量波长组合下,使共存的两种干扰组份的差吸光度为零,消除其干拢,而△A=A_(λ1)-K(A_(λ2)+A_(λ3))只与待测组份的浓度成正比。可直接测定三种组份或某一组份,无需进行分离和繁杂的计算,简便实用,可获得较好的准确度和精密度。讨论了选择波长组合的方法,并编制了程序,用计算机来选择最佳波长组合。     

Spectrophotometric investigation of protolytic equilibria of rutin

The dissociation constants of rutin in aqueous-methanol medium (6040 v/v), the values of which are pK₁=–2.92±0.06, pK₂=6.72±0.11, pK₃=8.26±0.05, pK₄=12.57±0.09, were estimated by using the spectrophotometric method. They were ascribed to the dissociation of protonated oxygen atom at position 1 and then to hydroxyl groups at positions 7, 4', 5, respectively. Resonance structures of H₃L^– ion of rutin were suggested and, by using them, the greater dissociability of the hydroxyl group at position 7 in relation to the –OH group at position 4' was explained.     

钍(Ⅳ)铬天青B-氯化十六烷基吡啶络合显色反应的研究

钍(Ⅳ)的光度法测定前人已有研究。本文系统地研究了在阳离子表面活性剂氯化十六烷基吡啶(CPC)存在下,Th(Ⅳ)与CAB显色反应的条件及光谱性能。实验结果表明,在pH5.0的邻苯二甲酸氢钾—氢氧化钠缓冲体系中,Th(Ⅳ)与CAB和CPC形成稳定的绿色     

用紫外光度法测定扑草净粉剂中扑草净含量的研究

扑草净（ｐｒｏｍｅｔｒｙｎｅ）化学名为２,４－二异丙氨基－６－甲疏基－均三嗪,是一种常用的除草剂,具有毒性低,选择性好的特点,目前己用于多种作物的杂草防治。扑草净的定量测定常用气相色谱法和电位滴定法。由于电位滴定法操作麻烦、结果不准确,色谱法又因仪器设备价格较贵而使用有限。寻找简易、快速的扑草净测定具有重要意义。我们根据扑草净在紫外光区２２１ｎｍ处有特征吸收峰的性质,建立了一种用紫外分光光度法测定扑草净的新方法,方法用于农药扑草净粉剂中扑草净含量的测定,结果令人满意。１实验部分１．１主要仪器和试…     

分光光度法测定汽油中的磷

提出了用磷钒钼酸分光光度法测定汽油中磷含量的方法，通过对汽油中可能存在的共存离子干扰进行了考察，确定了最佳测试条件。对合成标准样品分析，其相对误差小于±３．０％，相对标准偏差小于２．３％，对实际样品进行分析并进行了加标回收试验，磷回收率达到９８．８％～１０３．９％。是一种快速、可靠测定汽油中磷含量的方法。     

薯蓣皂甙元的分光光度法测定

本文以黄姜为主要对象研究了薯蓣皂甙元的定量测定方法，以香荚兰醛－高氯酸为显色剂，冰醋酸为溶剂，使皂甙元显色，用分光光度法在波长为５３０ｎｍ处测定薯蓣皂甙元的含量。从植物中提取的皂甙元不需分离可直接测定。在１．００～２０．００ｍｇ／Ｌ范围内呈良好的线性关系。     

Difference spectrophotometric determination of some pharmaceutically important thioxanthene derivatives in dosage forms

A Spectrophotometric method is described for the rapid determination of four thioxanthene derivatives, namely chlorprothixene, thiothixene, flupenthixol hydrochloride and clopenthixol hydrochloride. The method is based on measuring the first derivative spectrum (D ₁) of the oxidized drug relative to a solution of the underivatized drug. At the wavelength of maximum difference in first derivative (range 285–315 nm), only the oxidation products have an appreciable difference in first derivative and the oxidizing agent has no absorbance. The oxidation products (assumed to be the thioxanthone sulphoxides) are formed rapidly at room temperature by the addition of peroxyacetic acid, prepared by the slow reaction of hydrogen peroxide and glacial acetic acid. The first derivative of the absorbance is proportional to the concentration of the drugs in solution over the ranges 2–14 g ml^–1 for chloroprothixene, 2–20 g ml^–1 for clopenthixol hydrochloride, 2–24 g ml^–1 for thiothixene and 4–40 g ml^–1 for flupenthixol hydrochloride. The method is specific for the intact drug and can be adopted in the presence of oxidative and photochemical decomposition products and tablet excipients. The recoveries ranged from 99.7 ± 1.3 to 100.2 ± 1.5%. The validity of the method was tested by analysing synthetic samples of thioxanthenes and some dosage forms containing the drugs; the results were in accordance with those given by the official methods.     

双波长和三波长分光光度法同时测定乙醛酸和乙二醛

利用醛基的成肟反应，用双波长法，三波长法同时测定乙醛酸、乙二醛的含量。它们的回收率分别为１００．９％－１０２．３％（ｎ＝６）和９６．８％－１０３．０％（ｎ＝１１）。     

Determination of Ranitidine Hydrochloride in Pharmaceutical Preparations by Ultraviolet and Visible Spectrophotometry

Abstract

Ranitidine hydrochloride in tablets (T) and injections (I) was determined by ultraviolet spectrophotometry (UVS) at 313 nm and visible spectrophotometry (VISS) at 615 nm, after reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and ferric chloride. For UVS, Beer's law was obeyed in the range 5.0 – 18.0 μg/mL. The coefficients of variation (CV) for the samples T were 0.36% and 0.71% and for the samples I were 0.51% and 0.24%. The recovery average (RA) was 99.88%. For UVS, Beer's law was observed in the range 1.44 – 5.76 μg/mL. The CV for T were 0.72% and 0.59%, and for I were 0.53% and 0.61%. The RA was 99.39%. The precision and accuracy of the two methods were compared.     

Simultaneous spectrophotometric determination of Zinc(II) and Nickel(II) with 1-(2-pyridylazo)-2-naphthol

A new procedure for the simultaneous spectrophotometric determination of Zn(II) and Ni(II) with 1-(2-pyridylazo)-2-naphthol as chromogenic reagent has been developed. It is based on resolution of the mixed spectrum over the wavelength range 530–590 nm by applying a least-squares fitting program to standard spectra from each component. The spectra are recorded at an apparent pH of 5.0, provided by an acetate buffer in a mixed 6040 v/v 2-ethoxyethanol/water medium. The relative standard deviations for determination of 13.7 g of Ni and 31.0 g of Zn were 1.9 and 1.0%, respectively (8 replications). The method has been applied to the analysis of iron surfaces coated with a Zn-Ni alloy. The results are compared with those obtained by atomic-absorption spectrophotometry.