Spectral Investigation on Ruthenium(III)-allyl Thiourea System

Abstract

Ruthenium(III) forms a 1:2 complex with allyl thiourea. Conformity to Beer's law was observed for up to 12 pg/ml of ruthenium, in acidic medium.

The molar absorptivity of the complex is 1.66E+04 1 mol^?1 cm^?1, at 270 nm; the Sandell's sensitivity of the reaction for ruthenium is 0.0061 μg cm^?2 per 0.001 absorbance unit.

The tolerance to diverse ions is quite satisfactory.

The infrared spectra of allyl thiourea and of its ruthenium complex, recorded in the 2.5 - 50 μ region, reveal that only sulphur-to-ruthenium bonds are present in the complex.

A comparison with the main, most recent, spectrophotometric reagents for ruthenium is reported. The present method has the advantages of simplicity and reasonable sensitivity.     

Isonitroso-4-Methyl-2-Pentanone for Solvent Extraction and Spectrophotometric Determination of Palladium (II) at Trace Level

Abstract

Isonitroso-4-methyl-2-pentanone (HIMP) is proposed as a new reagent for extraction and photometric determination of Pd(II). The reagent forms a yellow complex with palladium in the pH range 4.0-5.0. The complex extracted into chloroform was measured at 330 nm. The molar absorptivity was found to be 5.37 × 10³ 1 mol^?1 cm^?1 and Sandell's sensitivity 20 ng cm^?2 Beer's law was obeyed over the concentration range 0.1-10.0 μg/ml of palladium. The method is applicable for palladium estimation in Ores and catalysts.     

Absorption Spectra of 4f Electron Transitions of Neodymium and Erbium with 8-Hydroxyquinoline-5-sulphonic Acid and Diethylamine Systems and Its Analytical Application

Abstract

In this paper the absorption spectra of 4f electron transitions of the systems of neodymium and erbium with 8-hydroxyquino-line-5-sulphonic acid and diethylamine have been studied by normal and third-derivative spectrophotometry. Their molar absorptivities are 80 l.mol^?1.cm^?1 for neodymium and 65 l.mol^?1.cm^?1 for erbium. Use of the third-derivative spectra, eliminates the interference by other rare earths and increases the sensitivity for Nd and Er. The derivative molar absorptivities are 390 1.mol^?1.cm^?1 for Nd and 367 1.mol^?1.cm^?1 for Er. The calibration graphs were linear up to 11.8 μg/ml of Nd and 12.3 μg/ml of Er, respectively. The relative standard deviations evaluated from eleven independent determinations of 7.2 μg/ml (for Nd) and 8.3 μg/ml (for Er) are 1.3% and 1.4%, respectively. The detection limits (signal to noise ratio = 2) are 0.2 μg/ml for Nd and 0.3 μg/ml for Er. The method has been developed for determining those two elements in mixture of lanthanides by means of the third-derivative spectra and the analytical results obtained are satisfactory.     

Column Chromatographic Preconcentration of Copper in Alloys and Complex Materials Using 9,10 Phenanthrenequinone Monoxime Supported on Naphthalene

Abstract

A solid chelating compound phenanthrenequinone monoxime PQM) supported on naphthalene provides a rapid and economical means of preconcentration and separation of copper from the aqueous samples. Copper forms a complex with PC:: supported on naphthalene in the column at pH 6.1–8.4 with a flow rate of 1 ml/min. The metal complex and naphthalene are dissolved out from the column with 5 ml of DMF and the absorbance is measured at 470 nm against reacent blank. Beer's law is obeyed in the concentration range 0.6 9.6 μg of copper in 5 ml of DMF. The molar absorptivity and sensitivity are 6.3×10⁴ L mol^?1 cm^?1 and 0.001 μg cm^?2 respectively.     

Complexing Properties of Uranium and Lanthanoids With 4-(2-Thiazolylazo)-6-Chlororesorcinol

Abstract

4-(2-Thiazolylazo)-6-chlororesorcinol (TAR-Cl) reacts sensitively with uranyl(II) and lanthanoids(III), and forms reddish-brown 1:1 and 1:2 complexes. The complexing behaviors were examined spectrophotometrically. The absorption maxima of the complexes are focused near 553 nm and the optimum pH for complexation lies between 6.5–8.8. Beer's law holds up to about 2 × 10^?5 mol 1^?1, with a molar absorptivity of 3.00 × 10⁴ 1 mol^?1 cm^?1 for uranium and 6 × 10⁴ 1 mol^?1 cm^?1 level for each lanthanoid. The absorptivities are increased with the atomic number, especially in light lanthanoids, that are correlative both to the lanthanoid contraction and the basicity of ortho hydroxyl group in the resorcinol ring, but such effects are not clearly recognized in heavy lanthanoids. Effect of masking agents was also examined, and uranium could be determined selectively in the presence of lanthanoid mixtures by the addition of CyDTA.     

Zero-Crossing Derivative Spectrophotometric Determination of Mercury(II) And Palladium(II) with 5-(3,4-Methoxyhydroxyphenylmethylene)-2-thioxo-1-3-thiazolidine and Cetyltrimethylammonium Bromide

Abstract

A method is proposed for the simultaneous determination of mercury(II) and palladium(II) by first-derivative spectrophotometry based on the absorption spectra of their complexes with 5-(3,4-Methoxyhydroxyphenylmethylene)-2-thioxo-1,3-thiazolidine [5-(3,4-methoxyhydroxybenzylidene) rhodanine]. Zero-crossing measurement technique is found suitable for the measurement of the first-derivative value at the specified wavelengths. Mercury(II) (0.4-1.4 μg ml^?1) and palladium(II) (0.08 - 1.8 μg ml^?1) in different ratios have been determined simultaneously. A critical evaluation of the proposed method is performed by statistical analysis of the experimental data.     

Spectrophotometric Determination of Thiosulfate,Thiocyanate and Thiourea Ions by Using Sodium Nitroprusside As a Complexing Agent

Abstract

Quantitative determination of thiosulphate, thiocyanate and thiourea ions spectrophotometrically has been investigated. The high absorptivity of the investigated ions-nitroprusside complexes at the optimum conditions indicates that concentrations of 10^?4–10^?3M of thiosulphate, thiocyanate and thiourea can be determined spectrophotometrically with fair accuracy. The effect of pH was studied and the optimum pH was determined to give the highest sensitivity. The validity of this method is supported by the constancy of the molar absorptivity.     

Spectrophotometric Determination of Palladium by the New Chromogenic Reagent N-Butyl - N'-(Sodium P-Aminobenzenesulfonate) Thiourea

Abstract

A highly sensitive spectrophotometric method for determination of palladium by the new chromogenic reagent (BPT) has been developed. In the presence of cetyltrimethylammonium bromide(CTMAB), palladium reacts with BPT to form a stable yellow complex in HAc-NaAc buffer solution of pH 4.6-5.6 at 294.4 nm with a molar absorptivity of 2.46 x 10⁵ l mol^?1 cm^?1. The method is simple, rapid and sensitive. Trace amounts of palladium in mineral and catalyst samples have been satisfactorily determined by the method.     

Extraction,Spectrophotometric, and Atomic Absorption Spectrophotometric Determination of Selenium With N-Phenylbenzohydroxamic Acid

Abstract

Solvent extraction spectrophotometric and atomic absorption spectrophotometric methods for the determination of selenium(IV) in microgram quantities are described. The selenium(IV) forms yellow colored complex with N-phenylbenzohydroxamic acid (PBHA) extractable into chloroform from 7 M HClO₄. Se-PBHA complex has maximum absorbance at 345 nm with a molar absorptivity 1.5 × 10⁵ 1 mol^?1 cm^?1 and Sandell's sensitivity 0.000526 μg /cm². Effect of molarity, reagent concentration, diverse ions on the extraction of selenium complex were studied. The selenium is determined in presence of tellurium.     

Spectrophotometric Determination of Diphenadione Via its Metal Complexes

Abstract

Spectrophotometric procedure is described for the quantitative determination of diphenadione [2-(diphenylacetyl)-1,3-indandione], based on direct spectrophotometric measurements of the absorbances of its iron (III), iron (II) and cobalt (II), metal complexes at 488 nm, 505 nm and (334 nm, 372 nm), respectively. The drug reacts with metals in the ratio of 3:1 and 2:1 for iron (III) and for both iron (II) and cobalt (II) respectively. The obtained complexes have apparent molar absorptivities of 1.48 × 10³ 1 mol^?1 cm^?1, 0.714 × 10³ 1 mol^?1cm^?1 and (1.70 × 10³ 1 mol^?1cm^?1, 1.93 × 10³ 1 mol^?1cm^?1) for iron (III), iron (II) and cobalt (II) complexes, respectively. The procedure is suggested for the determination of 51–400 μg.ml^?1 diphenadione via the iron (II) complex and 35–170 μg.ml^?1 diphenadione via both cobalt (II) and iron (III) complexes. The suggested procedure has accuracies of 99.79 ± 0.67%, 99.64 ± 0.37% and (100.09 ± 0.53%, 99.99 ± 0.42%) for the metal complexes of iron (III), iron (II) and cobalt (II), respectively.     

Spectrophotometric Determination of Palladium(II) with n-Hydroxy-N,N-Diphenylbenzamidine and 1 -(2-Pyridylazo)-2-Naphthol

A spectrophotometric method to determine palladium(II) at trace levels is based on the extraction of palladium(II) as a binary complex with N-hydroxy-N,N′-diphenylbenzamidine (HDPBA) in chloroform at pH 5.0 ± 0.2. The complex shows maximum absorbance at 400 nm with molar absorptivity 6.4 × 10³ L mol^?1 cm^?1. The sensitivity of the Pd(II)-HDPBA complex was enhanced by the addition of l-(2-pyridylazo)-2-naphthol (PAN). The green coloured complex shows maximum absorbance at 620 nm with molar absorptivity 1.58 × 10⁴ L mol^?1 cm^?1. Sandell's sensitivity and the detection limit of the method are 0.0067 μg cm^?2and 0.1 μg Pd(II) mL^?1, respectively. Most common metal ions associated with palladium metal do not interfere. The effects of various analytical parameters on the extraction of the metal are discussed.     

Infrared absorption spectra of cyanide complexes of group VIII metals with nitrogen- and sulphur-containing ligands

Research into the IR absorption spectra of the products of interaction between nitrosyl pentacyanide complexes of some Group VIII metals and thiourea and thiocyanate has been carried out in the region 400–4000 cm^?1.An assumption has been made concerning the formation of intermediates of the association type. The changes in the spectra during the formation of intermediates indicate a weakening of ligand bonds with a metal-complexing agent.The data obtained for the series of cyanide complexes of Group VIII metals with heterogeneous ligands allow us to suggest a strengthening of the M-S bond between thiourea and metals in the order Os > Ni > Co ? FeThe M-NCS bond between the thiocyanate group and metals of the iron family is practically equivalent.Osmium coordinates the SCN^? group through the sulphur atom.     

Some Arylidene-2-Pyridylhydrazone Derivatives as Reagents for Spectrophotometric Determination of Palladium (II)

Abstract

A method for spectrophotometric determination of palladium by complexation with Arylidene-2-pyridylhydrazone derivatives in 50% (V/V) ethanolic solution are described-Pd(II) forms a 1:1 complex with the reagents. Beer's law is obeyed over the range 0.2-6.5 μg ml^?1. The effect of pH, effect of excess reagent, stability of complexes as well as the tolerance amount of many metal ions have been reported. The method is applied, with fair accuracy, to the determination of pd(II) in synthetic solutions.     

The extractive spectrophotometric determination of palladium(ii) as the mixed-ligand complex with picolinealdehyde-2-hydroxy-5-phenylanil and chloride ion

The extraction of palladium(II) with chloroform in the presence of PHPA and chloride ions is described. The extracted species has an absorption maximum at 627 nm, and Beer's law is obeyed over the range 10–200 μg of palladium. The molar absorptivity is 4.90·10³ l mol^?1 cm^?1 at 627 nm. The 1:1:1 Pd(PHPA)-Cl complex is extracted from aqueous solution. The effect of foreign ions on the determination of palladium(II) is examined.     

2-Methyl-1, 4-Naphthoquinone Thiosemicarbazone as a Sensitive and Selective Chromogenic Reagent for Microdetermination of Palladium (II)

A simple, sensitive and selective procedure has been developed for the spectrophotometric determination of palladium. Palladium (II) reacts with 2-methyl-1,4-naphthoquinone thiosemicarbazone to form an orange brown complex in the pH range 8.2–9.5. The sensitivity, in terms of Sandell's definition, is 0.0025 μg Pd/cm² at 500 nm. The system adheres to Beer's law upto 2.66 ppm of palladium and optimum concentration range for the determination of the metal is 0.3–2.29 ppm with molar absorbtivity of 4.2×10⁴ ? mole^?1 cm^?1. The complex has 1:1 molar composition, as deduced by Job's method. The determination of palladium has been carried out in presence of foreign ions especially in presence of eighth group metals.     

Diazotised 4-Nitroaniline as a Chromogenic Reagent for the Determination of Indole Derivatives in Certain Pharmaceutical Preparations

Abstract

A sensitive colorimetric method has been devised for microdetermination of six indole derivatives; ergotamine tartrate, methylergometrine maleate, dihydroergocornine methanesulphonate, dihydroergocristine methanesulphonate, dihydroergocryptine methanesulphonate and pindolol, both in pure form and in pharmaceutical preparations. The method is based on the reaction of indole moiety with diazotised 4-nitroaniline in buffer solution of pH 6 to produce a stable yellow monoazo dye. Beer's law is obeyed over final concentration ranges 8–32 μgm1^?1 for ergotamine tartrate, 4–48 μgml^?1 for methylergometrine maleate, 8–56 μgml^?1 for dihydro-ergot alkaloids and 1–10 μgml^?1 for Pindolol with apparent molar absorptivity range (7.62 × 10³?2.61 × 10⁴) 1.mole^?1.cm^?1. A study has been made to determine the optimum conditions of the colour reaction.     

Spectrophotometric Determination of Manganese with 4(5)-Imidazolealdoxime (Imalox)

Abstract

A method is described for the spectrophotometric determination of manganese by means of its complex with 4(5)-imidazolealdoxime, IMALOX, formed in alkaline medium. The colour system has its absorption maximum at 350 nm and obeys Beer's law over the range 0.8–8.0 μg of Mn per ml. The optimum range is 1–5 μg m^?1. The molar absorptivity is 7850 1 mol^?1 cm^?1. Relatively few ions interfere, and these can be masked with cyanide, tartrate and NTA. The experimental results have been critically analyzed and a comparison with the main spectrophotometric reagents for manganese is presented.     

Spectrophotometric Determination of Palladium with Sodium Ethylene-Bis-Selendglycollate

Abstract

SUMMARY

Palladium was determined spectrophotometrically with sodium ethylene-bis-selenoglycollate in acid medium. The system obeys Beer' law in the range 0.25–0, 3 5 μg.ml^?1 and the molar absorptivity is 2.4 × 10⁴ 1. mol^?1 .cm^?1. Determination of palladium in the presence of many ions is reported.

In spite of the fact that selenium compounds have rarely been used as organic analytical reagents and one finds many palladium determination methods in the literature, this paper fits into the general Purpose reported before ^1,2 :systematic comparison of organic sulphur, sellenium and tellurium compounds as analytical reagents in agreement with propositions made some years agp ^3,4

In previous work⁵ the behaviour of the ethylseleno glycollic (L₁), selenodiglycollic (L₂) and ethylene-bis-selenoglycollic (L₃) anions in acidic solutions of some “soft”, “borderline” and “hard” cations was studied.

The results obtained for Pd(II) afforded evidences that its determination could be run with the three mentioned ligands.

Nevertheless, L₃ was selected because it provides the most sensitive signal and its synthesis is very simple and its overall yield is excellent⁶

From the qualitative study⁵ the foreseen selectivity could present some restrictions, but there is little doubt about the usefulness of the method that will be proposed, in various schemes of determination. Similar comments Beamish have been made about EDTA method for Pd(II) determination⁸     

Liquid-liquid extraction and spectrophotometric determination of palladium with 2-mercaptobenz-amide

2-Mercaptobenzamide (MBA) was investigated as a reagent for the extraction of palladium. The palladium complex of MBA was extracted into tributyl phosphate (TBP). The pK_a of the ligand was 5.45 with the stability constant of the palladium complex β₂=10^7.1. The composition of the complex in TBP was Pd:MBA:TBP=1:2:2. Addition of sodium chloride accelerated the rate of extraction. Various interfering ions could be masked with EDTA; Ag(I), Au(III), Os(VIII), Se(IV), Te(IV) etc. interfered. The molar absorptivity was 1.59×10⁴ l mol^?1 cm^?1; 1–35 μg Pd could be determined at pH 6.0.     

Liquid-Liquid Extraction,Photometric and Atomic Absorption Spectrophotometric Determination of Mercury

Abstract

A selective and sensitive spectrophotometric and atomic absorption spectrophotometric method is developed for the determination of traces of mercury with N-phenylcinnamohydroxamic acid (PCHA) in the environment. Mercury is extracted into a chloroform solution of PCHA at pH 8.5-10.0 and determined by AAS. The mercury hydroxamate binary complex is yellow in colour having a maximum absorbance at 390 nm and molar absorptivity 4.3 × 10³ 1 mol^?1 cm^?1, sandell sensitivity 0.0466 μg/cm². The ternary system using 1-(2-pyridylazo)-2-naphthol has molar absorptivity 8.82 × 10³ 1 mol^?1 cm^?1 at 550nm, sandell sensitivity 0.0228 μ/cm². Beer's law is obeyed in the concentration range of 2.37-38.0 ppm and 0.80-19.5 ppm of mercury for binary and ternary system, respectively. The extraction of Hg-PCHA binary system is studied with a liquid cation exchanger, bis-(2-ethyl hexyl) phosphoric acid (HDEHP) and found to have better selectivity than Hg-PCHA-PAN system. The molar absorptivity of the Hg-PCHA-HDEHP system is 8.82 × 10³ 1 mol^?1 cm^?1 at 390 nm and Beer's law is obeyed in the concentration range of 0.47-20 ppm of mercury.

The present method is applied to the determination of mercury in eye drops, aurvedic drugs and environmental samples.