Spectrophotometric determination of chlorpromazine hydrochioride by 1,10-phenanthroline

在HAc-NaAc缓冲介质中,盐酸氯丙嗪(CPZ)能定量使Fe(Ⅲ)还原为Fe(Ⅱ),还原生成的Fe(Ⅱ)与邻二氮菲反应生成稳定的红色络合物,并且在一定范围内,CPZ的浓度和生成的红色络合物的吸光度呈良好的线性关系.据此,提出邻二氮菲-Fe(Ⅲ)体系测定盐酸氯丙嗪的新方法.在优化的实验条件下,盐酸氯丙嗪的质量浓度在0.040～15.00mg/L范围内与吸光度呈现良好的线性关系,线性相关系数R=0.9995,摩尔吸光系数ε=2.8×104L·mol-1·cm-1,检出限为0.020mg/L.11次重复测定的相对标准偏差小于2.9％.该方法用于药物中盐酸氯丙嗪的测定,结果满意.     

邻二氮菲分光光度法测定盐酸氯丙嗪

在HAc-NaAc缓冲介质中,盐酸氯丙嗪(CPZ)能定量使Fe(Ⅲ)还原为Fe(Ⅱ),还原生成的Fe(Ⅱ)与邻二氮菲反应生成稳定的红色络合物,并且在一定范围内,CPZ的浓度和生成的红色络合物的吸光度呈良好的线性关系。据此,提出邻二氮菲-Fe(Ⅲ)体系测定盐酸氯丙嗪的新方法。在优化的实验条件下,盐酸氯丙嗪的质量浓度在0.040～15.00 mg/L范围内与吸光度呈现良好的线性关系,线性相关系数R=0.9995,摩尔吸光系数ε=2.8×104 L.mol-1.cm-1,检出限为0.020 mg/L。11次重复测定的相对标准偏差小于2.9%。该方法用于药物中盐酸氯丙嗪的测定,结果满意。     

Spectrophotometric determination of copper in plutonium metal with 2,9-dimethyl-1,10-phenanthroline

A spectrophotometric method for the determination of copper plutonium has been developed. The copper is complexed with neocuproine, extracted into chloroform, and the absorbance read at 457 mmu. The average relative error of the method is -1.4% with an average relative standard deviation of 4%.     

Spectrophotometric determination of iron with 1,10-phenanthroline in the presence of copper

Summary Cupric ion forms a very stable complex with triethylenetetramine (trien). It has a very weak absorption at 400–460 nm, however, the ferroin shows a very strong absorption at 480–520 nm. The use of trien-tartrate as duel masking agents for copper has been proved to be successful, and is superior to EDTA or citrate-EDTA in the determination of iron with 1,10-phenanthroline. The colour reaction may be accelerated at 60° for 10 min. The new method has been applied to the analysis of U. S. NBS standard solder alloy samples for iron.

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Die spektrophotometrische Bestimmung von Eisen mit 1,10-Phenanthrolin in Gegenwart von Kupfer

Zusammenfassung Kupfer(II)ionen bilden mit Triethylentetramin (Trien) einen sehr beständigen Komplex. Dieser absorbiert sehr schwach bei 400–460 nm, Ferroin hingegen zeigt eine sehr starke Absorption bei 480–520 nm. Die Verwendung von Trien-Tartrat als Maskierungsmittel für Kupfer erwies sich als zielführend und ist für die Eisenbestimmung mit 1,10-Phenanthrolin besser geeignet als EDTA oder Zitrat-EDTA. Die Farbreaktion läßt sich durch Erwärmen auf 60°C für 10 min beschleunigen. Die vorgeschlagene Methode hat sich bei der Analyse von NBS-Standardproben von Lot-Legierungen bewährt.

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On leave from Nanking Institute of Chemical Technology, Nanking, China.     

Spectrophotometric determination of iron in highly alkaline solution with 4-hydroxy-1,10-phenanthroline

4-Hydroxy-1,10-phenanthroline forms a stable tris-chelate with iron(II) in the range of alkalinity from pH 10 to 2M sodium hydroxide, with molar absorptivity 1.19 x 10(4) l.mole(-1).cm(-1) at 545 nm. The determination of iron is performed by adding the phenanthroline, stannous chloride, and iron-free sodium hydroxide to the sample to give pH > 13; stannite is the active reductant. Beer's law is obeyed over the iron concentration range from 1 x 10(-5) to 8 x 10(-5)M. Advantages over existing methods are the use of stannous chloride instead of sodium dithionite, which avoids the problem of turbidity, and the stability of the iron(II) chelate towards oxidation by air. The conditional reduction potential at pH 11 for the iron(III)/iron(II) complex couple is 0.39 V.     

Spectrophotometric determination of dissolved oxygen with tris(4,7-dihydroxy-1,10-phenanthroline)iron(II)

Tris(4,7-dihydroxy-1,10-phenanthroline)iron(II) reacts rapidly and quantitatively with dissolved oxygen in alkaline aqueous solution. In ammoniacal solution, the reaction is accompanied by the disappearance of the intense red colour of the iron(II) compound, which gives way to the pale gray, slightly-dissociated ion tris(4,7-dihydroxy-1,10-phenanthrolinefiron)(III). By measurement of the absorbance of a solution containing the ferrous compound before and after the injection of an oxygen-containing solution, the concentration of dissolved oxygen in the sample can be accurately determined in the range 1-20 ppm.     

Colorimetric determination of iron (III) with 1,10-phenanthroline

Summary A new procedure has been developed for the colorimetric determination of iron(III). It consists in the reduction of iron (III) in dilute sulphuric acid medium (0.1 to 1.0 N) with an excess of hypophosphite (1100) at room temperature using one or two drops of 0.1% PdCl₂ solution as catalyst, and then complexing the reduced iron with 1.10-phenanthroline.Iron (III) can also be reduced with phosphite using the PdCl₂ catalyst and boiling for 5 to 10 min on a hot plate. The molar concentration of phosphite is preferably kept 500 times that of ferric ion.

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Zusammenfassung Es wurde ein neues Verfahren zur colorimetrischen Bestimmung von Eisen(III) ausgearbeitet. Dabei wird das Eisen in verd. Schwefelsäure (0,1–1,0 n) mit einem Überschuß von Hypophosphit (1100) bei Zimmertemperatur unter Verwendung von ein oder zwei Tropfen 0,1%iger PdCl₂-Lösung als Katalysator reduziert und anschließend das zweiwertige Eisen mit 1,10-Phenanthrolin umgesetzt.Eisen(III) kann auch mit Phosphit reduziert werden, wenn man ebenfalls PdCl₂ als Katalysator verwendet und 5–10 min erhitzt. Die molare Konzentration des Phosphits soll dabei das 500fache von der des Eisens betragen.

     

Spectrophotometric determination of tannins in tea and beer samples with iron(III) and 1,10-phenanthroline as reagents

A simple and accurate spectrophotometric method is proposed for the determination of tannins in tea and beer samples based on the reduction of iron(III) to iron(II) by tannins at 80 degrees C for 20 min. The iron(II) was then reacted with 1,10-phenanthroline at pH 4.4 to form a coloured complex. Background correction could be effected by precipitating the tannins in the sample solution twice with gelatin and kaolin. Absorbance measurements were made at 540 nm and the calibration graph was linear from 0 to 5.5 micrograms ml-1 of tannic acid with a slope of 0.213 A p.p.m.-1. The precision for the determination of tannins in a tea sample containing 9.45% of tannins was 1.8%. Most of the ingredients commonly found in tea and beer samples do not interfere with the determination. Several tea and beer samples were analysed for their tannin content using the proposed method.     

Spectrophotometric determination of vanadium with n-benzoyl-o-tolylhydroxylamine

N-Benzoyl-o-tolylhydroxylamine is shown to provide a virtually specific reagent for the spectrophotometric determination of vanadium. The reddish-violet complex formed with the reagent in 4–8 N hydrochloric acid after extraction with chloroform shows absorption maxima at 510 mm, and obeyes Beer's law from 0.5 to 10 μg with an optimum range of 2–10 μg; the percent relative error is 2.7. The sensitivity is 0.0108 μg V/cm². The complex contains the metal and the reagent in a ratio of 1:2 and the dissociation constant is of the order of 10^-9.     

熔融萘萃取铁(Ⅱ)-4,7-二苯基-1,10-菲啰啉-四苯硼酸盐三元络合物光度法测定铁

研究了以熔融萘作为萃取剂,以4,7 二苯基 1,10 菲口罗啉作为显色剂,测定天然水中微量铁的分光光度法。在pH4的条件下,铁(Ⅱ)与4,7 二苯基 1,10 菲口罗啉和四苯硼酸盐能够形成红色三元络合物。在熔融萘存在下,此络合物可以迅速萃入熔融萘。将含有络合物的萘冷却、固化、分离,配制成25mL丙酮溶液,对其进行分光光度分析。实验表明,该络合物最大吸收波长为534nm,摩尔吸光系数和桑德尔灵敏度分别为2×104L·mol-1·cm-1和0.0025μg/cm2,铁(Ⅱ)的质量浓度在0～2 0μg/mL的范围内符合比耳定律。大多数常见离子不干扰测定。已应用于天然水中微量铁的测定。     

Spectrophotometric determination of iron(II) with 1,10-phenanthroline in the presence of large amounts of iron(III)

A study was made to establish proper conditions for the selective determination of Fe(II) by the 1,10-phenanthroline method in the presence of large amounts of Fe(III). It was shown that fe(III) is effectively masked by fluoride. The pH of the solution to be masked should be below 2.5 in order to prevent acceleration by the fluoride of aerial oxidation of Fe(II).     

Indirect spectrophotometric determination of palladium using 1,10-phenanthroline as reagent

Summary The spectrophotometric method for the determination of palladium is based upon the addition of a standard 1,10-phenanthroline solution to precipitate Pd(phen)Cl₂ and the determination of 1,10-phenanthroline concentration of the supernatant solution. The absorbancy readings were made in the absorption maximum at about 271 nm, in the concentration range of 10^–6 to 10^–5M 1,10-phenanthroline in 0.1 M hydrochloric acid and 0.1% hydroxylamine hydrochloride. For the phenanthroline system Beer's law is valid. Ions which either form with phenanthroline very strong complexes or interfere with the spectrophotometric determination of 1,10-phenanthroline must be absent. The method is simple, rapid, accurate and applicable to the macro and micro-determination of palladium in different systems. Standard deviation was found to be 0.085 ppm (in pure Pd solutions).

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Indirekte spektrophotometrische Bestimmung von Palladium mit 1,10-Phenanthrolin

Zusammenfassung Das Verfahren beruht auf der Fällung von Pd(phen)Cl₂ durch Zusatz einer bestimmten Menge Standard-1,10-Phenanthrolinlösung und spektrophotometrischer Bestimmung des Überschusses.Die Messungen werden bei dem Absorptionsmaximum bei etwa 271 nm und einer Konzentration von 10^–6M bis 10^–5M 1,10-Phenanthrolin in 0,1 M HCl und 0,1% Hydroxylaminhydrochlorid enthaltender Lösung durchgeführt. Das 1,10-Phenanthrolinsystem folgt dem Beerschen Gesetz. Ionen, die entweder mit 1,10-Phenanthrolin starke Komplexe bilden oder die spektrophotometrische Bestimmung von 1,10-Phenanthrolin beeinflussen, müssen abwesend sein. Die Methode ist einfach, rasch und genau und kann für Mikro- und Makrobestimmungen in verschiedenen Systemen angewendet werden. Die Standardabweichung beträgt 0,085 ppm (in reinen Pd-Lösungen).

     

Spectrophotometric determination of vanadium in biological materials with N-benzylbenzohydroxamic acid

A spectrophotometric method for the determination of vanadium in biological materials with N-benzylbenzohydroxamic acid is proposed. The method is highly selective for vanadium and is free from rigid control of reaction conditions. No separation of iron prior to the determination of vanadium is necessary. Cu(II), Co(II), Ni, Mn(II), Cr(III), Ce(IV), Zr, Mo(VI), Ca, Sr, Ba, UO(2)(II) and many others metal ions do not interfere. Fairly large quantities of Ti(IV) and W(VI) are tolerated.     

Spectrophotometric determination of vanadium(IV) with nitrilotriacetic acid

A new and convenient spectrophotometric method for the estimation of vanadium(IV) with NTA is described. The minimum ratio of metal ion to ligand, working pH, wavelength for maximum absorbance of the complex ion, and the effect of various cations and anions are described. The complex ion obeys Beer's law in the concentration range 1–32 mmol/liter of the vanadium(IV) ion. It is observed that iron(II), cobalt(II), nickel(II), copper(II), and oxidizing anions such as chromate and nitrite interfere in this determination, whereas managanese(II), chromium(III), iron(III), and anions like nitrate, chloride, bromide, iodide, thiocyanate, sulfate, and sulfite do not have any effect. Excessive amounts of acetate, phosphate, oxalate, tartrate and thiosulfate must also be avoided in this determination. Anions and cations which interfere in the determination of vanadium(IV) by NTA should not be present in the system.     

Spectrophotometric determination of vanadium in different oxidation states with pyrogallol

Determination of vanadium at low concentrations is easily performed with pyrogallol as a ligand which forms a bluish-violet complex with vanadium(III), (IV) or (V). The colour of the bluish-violet complex (lambda(max) = 580 nm) contrasts well with the colour of both pyrogallol and vanadium. The complexes are stable for several hours. Beer's law is obeyed over the range 0-14 mug/ml vanadium at pH 6. The apparent molar absorptivity at 580 nm is (7.75 +/- 0.25) x 10(3)1.mole(-1).cm(-1). The effects of diverse ions on the determination of vanadium have been fully studied. Only Mo(VI) and W(VI) interfere seriously. The method is selective, sensitive and can be applied to the determination of total vanadium in a variety of samples.