Spectrophotometric determination of copper with cuproine

A study is devoted to the spectrophotometric determination of traces of copper with cuproine as reagent. After having determined the absorption spectrum of the complex, the authors have studied successively the partition coefficient water/ isoamyl alcohol ; the stability of the complex (colour); the influence of some factors: pH, foreign ions, temperature, the quality of isoamyl alcohol, excess reagent; and the validity of Beer's law. Two different calibration curves were determined, one based on complete extraction of the complex and the other based on an empirical method, which is very rapid. In both cases the mean square error is less than 1%.Finally, analysis methods were worked out for the determination of traces of copper in plants, animal tissues and blood, in water, in lamp-black and in steel.     

Spectrophotometric determination of copper with tiron

The reagent Tiron forms a soluble greenish-yellow complex with cupper. The sensitivity of the colour reaction is 0.24 mμ of copper/cm₂. The colour system at a pH of 6.1 to 6.9 is stable for over 24 h and shows a maximum absorption at 375 mμ. It obeys Beer's law at the latter wave length within a copper concentration of 10 to 160 p.p.m. The optimum range, however, is from 50 to 160 p.p.m. of copper, where the percent relative analysis error per 1% absolute photometric error is 2.94. JOB's method of continuous variation and the molar ratio method of YOE et al.² indicate that in solution the complex contains the metal and the reagent in a ratio of l : 2, with a dissociation constant on the order of 5.3 ? 10^-6.     

Spectrophotometric determination of copper with uramyldiacetic acid

A new method for the spectrophotometric determination of copper using uramyldiacetic acid as chromogenic reagent is proposed. The complex is formed in a wide pH range (2.5–9); but in order to avoid the potential conversion of UDA in murexide it is convenient to work at pH < 3: and has a maximum of absorption at 775 nm. Beer's law is obeyed in the interval 20–420 μg of copper(II)/ml. The Ringbom optimal range falls between 70 and 400 μg of copper(II)/ml, with a minimum photometric error of 2.8. The reaction between the metal and the ligand takes place in the ratio 1:1. The method has been applied to the determination of copper in ores with low content of the metal.     

Spectrophotometric determination of copper with hydrochloric acid

A procedure is proposed whereby copper may be determined spectrophotometrically by means of the very near infrared absorption of its complex ion with hydrochloric acid. Only stannous and ferrous ions are serious interferences and they may be oxidized with nitric acid or with ammonium persulfate to avoid such interference. The method is simple and rapid and is capable of reasonably good precision and accuracy.     

Spectrophotometric determination of copper(II) with 3-thianaphthenoyltrifluoroacetone

Summary Two visible spectrophotometric methods are described for the determination of Copper(II) with 3-thianaphthenoyltrifluoroacetone at a pH of 4.0. The effect due to pH, time, solvents, reagent concentration and diverse ions are reported. Beer's law is obeyed in both cases and the molar extinction coefficients at 410 and 430 nm are 9.3·10² and 2.9·10² respectively.

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Zusammenfassung Zwei spektrophotometrische Verfahren zur Bestimmung von Kupfer(II) mit 3-Thianaphthenoyltrifluoraceton bei pH 4,0 wurden beschrieben. Der Einfluß von pH, Zeit, Lösungsmitteln, Reagenskonzentration und von diversen Fremdionen wurde ermittelt. Das Beersche Gesetz ist in beiden Fällen erfüllt. Der molare Extinktionskoeffizient beträgt bei 410 bzw. 430 nm 9,3·10² bzw. 2,9·10².

     

Spectrophotometric determination of copper with triethenetetramine in electroless plating baths

Summary The blue colored triethenetetramine (TRIEN) complex formed at p_H 10 in the presence of PDTA, formaldehyde, and cyanide offers a highly selective method for determining copper in the mg range. All constituents in the plating bath have been studied for their possible effects on forming the copper TRIEN complex. This method is based on the formation of a mixed complex of copper, TRIEN, and halides.

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Zusammenfassung Der bei p_H 10 in Gegenwart von Propylendiamintetraacetat, Formaldehyd und Cyanid entstehende, blau gefärbte Triäthylentetramin-(TRIEN-)Komplex bietet die Grundlage für eine hochselektive Methode zur Bestimmung von mg-Mengen Kupfer. Alle Bestandteile eines Plattierbades wurden hinsichtlich ihrer Beteiligung an der Bildung des Kupfer-TRIEN-Komplexes geprüft.

     

Spectrophotometric determination of trace copper in water samples with thiomichlersketone

A simple and sensitive spectrophotometric method for determination of trace copper in water samples is proposed. In the presence of pH 4.6 HAc-NaAc buffer solution and surfactant polyethylene octyl phenyl ether (OP) medium, copper reacts with thiomichlersketone (TMK) to form a stable 1:4 complex. The complex Cu(II)-TMK-OP shows maximum absorbance at 500 nm with a molar absorptivity value of 5.7x10(4) l mol-1 cm-1. Beer's law is obeyed for copper concentrations in the range of 0-15 microg/25 ml. The average recovery of copper is between 95.8 and 106%. The method has been applied for determination of trace copper in different water samples with satisfactory results.     

Spectrophotometric determination of trace copper with a Cu-diethyldithiocarbamate-beta-cyclodextrin colour system

A simple, selective and accurate spectrophotometric method for determination of trace copper with diethyldithiocarbamate(DDTC) in the presence of beta-cyclodextrin(beta-CD) in ammonia media has been developed. The apparent molar absorptivity of Cu(II)-DDTC-beta-CD inclusion complex is 1.3 x 10(4) 1 . mole(-1) . cm(-1) at 436 nm, and Beer's law is obeyed for copper in the range 0-150 mug/25 ml. The detection limit is 4.38 x 10(-7)M(S/N = 3). The proposed method has been successfully applied to the determination of copper in aluminium alloys, soils, millet, wheat flour, herbs, vegetables and some traditional Chinese herbal medicines with satisfactory results.     

Spectrophotometric study of the determination of copper with ammonium 1-pyrrolidinecarbodithioate

A new spectrophotometric method for the determination of traces of copper has been developed. The method is based on the formation of a stable 1:2 complex of copper(II) and 1-pyrrolidinecarbodithioate and the isolation of this complex by extraction into chloroform. The absorbance is measured at either 269 nm or 435 nm. The detection limit is 0.03 mug, of copper per ml for absorbance measurements at 435 nm.     

Spectrophotometric determination of copper in alloys using naphthazarin

Naphthazarin (5,8-dihydroxy-1,4-naphthoquinone; Naph) is proposed as a chromogenic reagent for the spectrophotometric determination of copper(II). The polynuclear complex has a mole ratio of Cu:Naph=4:6 in a 50% v/v ethanol/water medium containing 0.1 M ammonium acetate and 1.5% (w/v) sodium dodecyl sulfate. The copper-naphthazarin complex shows an absorption maximum at 330 nm with a molar absorptivity of 1.84x10(4) l mol(-1) cm(-1). Beer's law is obeyed up to 4.5 ppm of copper(II). The method was applied for copper determination in alloy samples with satisfactory results.     

沉淀浮选铜光度法测定头孢曲松钠

建立了沉淀浮选铜测定头孢曲松钠的新方法。研究表明:pH4.0,头孢曲松钠的降解产物中的巯基能将Cu(Ⅱ)还原成Cu(I),所生成的Cu(I)与降解产物中的巯基生成白色乳状硫化物沉淀。通过测定溶液中剩余Cu(II)的吸光度,可以间接测定头孢曲松钠的含量。线性方程:A=4.803+0.0886ρ(μg/mL),线性范围为0.60～35μg/mL,相关系数r=0.9996,表观摩尔吸光系数ε=5.1×104L·mol-1.cm-1。方法已用于测定头孢曲松钠注射剂中头孢曲松钠的含量。     

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 aluminum and copper ions using spadns

Aluminum and copper ions are selectively estimated spectrophotometrically. These ions form colored complexes with spadns which have a maximum absorbance at 580 nm. The complexes formed with both cations are stable and pH dependant; aluminum is favorably complexed at pH 5, while copper is complexed at pH 7.The percentage recoveries were found to be 99.69 ± 0.75 and 99.32 ± 0.6 with a minimum detection limit of 0.08 and 0.23 g ml^–1 for aluminum and copper ions respectively. There is insignificant interference from the 10-fold concentrations of other metal ions under the proposed reaction conditions.     

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 copper as tetraphenylarsonium or tetraphenylphosphonium thiocyanate-cuprate

The spectrophotometric determination of copper(II) with thiocyanate by extraction of the tetraphenylarsonium and tetraphenylphosphonium ion-association complexes is described. The extracted complexes in chloroform have a maximum absorbance at 465 nm, obey Beer's law in the range of 3–50 ppm of copper, and are stable for at least 3 hr. The molar absorptivity of the method is 2.8 × 10³ liters mol^?1 cm^?1. The compositions of the extracted complexes were studied in solution and they are [(C₆H₅)₄X]₂[Cu(NCS)₄] (X = As, P).     

Spectrophotometric determination of copper(II) using oximidobenzotetronic acid

Summary Oximidobenzotetronic acid (OBTA) is proposed as a sensitive spectrophotometric reagent for the estimation of 0.5–3.0 ppm of copper(II) at 427 nm in 50% dioxan at p_H 5.3–7.5. For the estimation of 2 ppm Cu(II), 1.3 ppm Ni(II), 1.3 ppm Co(II), 3.2 ppm Fe(II), 10.3 ppm Fe(III), 9.7 ppm Ce(IV), 300 ppm acetate, 160 ppm oxalate, 95 ppm tartrate, 50 ppm citrate, as well as Zn(II), Cd(II), Hg(II)) Pb(II), Mn(II), As(III) as well as (V), Th(IV), Be(II), Ce(III), La(III), V(V) and Mo(VI), even when present in large quantities, do not interfere. The interference due to 25 ppm Bi(III), 20 ppm Sb(III), 20 ppm Sn(II), 25 ppm Sn(IV) and 30 ppm W(VI) can be removed by the addition of 95 ppm tartrate ions.

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Zusammenfassung Oximidobenzotetronsäure wurde als empfindliches Reagens zur spektrophotometrischen Bestimmung von 0,5 bis 3,0 ppm Kupfer(II) bei 427 nm in 50%iger Dioxanlösung bei p_H 5,3 bis 7,5 vorgeschlagen. Die Anwesenheit von 1,3 ppm Ni(II), 1,3 ppm Co(II), 3,2 ppm Fe(II), 10,3 ppm Fe(III), 9,7 ppm Ce(IV), 300 ppm Acetat, 160 ppm Oxalat, 95 ppm Tartrat, 50 ppm Citrat sowie die Anwesenheit auch großer Mengen Zn(II), Cd(II), Hg(II), Pb(II), Mn(II), As(III) bzw. (V), Th(IV), Be(II), Ce(III), La(III), V(V) und Mo(VI) stören die Bestimmung von 2 ppm Cu(II) nicht. Der störende Einfluß von 25 ppm Bi(III), 20 ppm Sb(III), 20 ppm Sn(II), 25 ppm Sn(IV) und 30 ppm W(VI) kann durch Zusatz von 95 ppm Tartrat beseitigt werden.