Spectrophotometric determination of iron(III)-dimethyldithiocarbamate (ferbam) using 9-(4-carboxyphenyl)-2,3,7-trihydroxyl-6-fluorone

A spectrophotometric method was developed for the determination of iron(III)-dimethyldithiocarbamate (ferbam) by concerting it into an iron(III)-9-(4-carboxyphenyl)-2,3,7-trihydroxyl-6-fluorone complex. In NH₃-HAc buffer solution (pH 6.5), the reagent reacts with ferbam to form a blue complex with a maximum absorption peak at 640 nm. The reaction can be completed rapidly at room temperature and the absorbance is stable for at least 24 h. The apparent molar absorption coefficient, Sandell’s sensitivity of the complex, the detection limit and the relative standard deviation were found to be 1.06×10⁵ l mol⁻¹ cm⁻¹, 3.9 ng cm⁻², 2.2 ng ml⁻¹ and 1.06%, respectively. From 0 to 75 μg of ferbam in 25 ml solution the absorbance obeyed Beer’s law. The effect of foreign ions and other dithiocarbamates were also studied in detail. The results indicated that all coexisting ions examined can be tolerated in considerable amounts, especially other dithiocarbamates such as ziram and zineb, which always interfere with the determination of ferbam in the literature. The proposed method is very sensitive, selective and simple, it has been applied to determine ferbam in commercial samples.     

Capillary electrophoretic determination of ferric dimethyldithiocarbamate as iron(III) chelate of EDTA

A simple and reliable thin-layer chromatographic method for the determination of N,N-diethyl-m-toluamide (DEET) and dimethyl phthalate (DMP) in raw material and cosmetic products was developed and validated. A benzene-diethyl ether-cyclohexane (5:3:2, v/v/v) solvent system was used for quantitative evaluation of chromatograms. The chromatographic zones corresponding to the spots of DEET and DMP on the silica gel plates were scanned in the reflectance/absorbance mode at 230 nm. The method was found to be reproducible and convenient for the quantitative analysis of DEET and DMF in raw material and cosmetic products.     

Spectrophotometric determination of iron(III) with EDTA tetrahydrazide

The tetrahydrazide of ethylenediamine tetraacetic acid (NH₂NH)₄-EDTA was synthesized from the EDTA ester and hydrazine hydrate in ethanolic solution, the resulting (NH₂NH)₄-EDTA being recrystallized in 60% ethanol. When the spectrophotometric study of the iron(III) (NH₂NH)₄-EDTA complex in aqueous solution was made two absorption maxima at 530 and 450 nm at pH 4.5 and 11.0, respectively, were found. Beer's law is obeyed in the range 1.0–20.0 μg Fe(III) ml^?1 at 530 nm and pH 4.5 and 0.5–12.0 μg Fe(III) ml^?1 at 450 nm and pH 11.0, the molar absorptivities being 1.95 × 10³ 1 mol^?1 cm^?1 at 530 nm and 3.35 × 10³ 1 mol^?1 cm^?1 at 450 nm, respectively. The Ringbom optimal interval falls between about 3 and 18 μg Fe(III) ml^?1 at 530 nm and about 2–14 μg Fe(III) ml^?1 at 450 nm. The reaction between the metal and the ligand was also investigated. The method has been successfully applied to the determination of iron in talcs.     

Spectrophotometric determination of iron(III) with 3-thianaphthenoyltrifluoroacetone

Summary 3-Thianaphthenoyltrifluoroacetone has been proposed for the spectrophotometric determination of iron(III). The 31 complex is very stable and can be extracted from acid solution into chloroform. Beer's law is obeyed and the molar extinction coefficient is 5.0·10³ at 516 nm. Relatively large amounts of cobalt, nickel and copper are tolerated. The method is simple, convenient and reproducible.

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Zusammenfassung 3-Thianaphthenoyltrifluoraceton wurde für die spektrophotometrische Eisen(III)-bestimmung vorgeschlagen. Der 31-Komplex ist sehr beständig und läßt sich aus saurer Lösung mit Chloroform extrahieren. Die Farbe entspricht dem Beerschen Gesetz, die molare Extinktion beträgt 5,0·10³ bei 516 nm. Relativ große Mengen Kobalt, Nickel und Kupfer stören nicht.

     

Spectrophotometric determination of iron(III) and total iron by sequential injection analysis technique

A procedure for determination of concentrations of iron(III) and total iron by sequential injection analysis is described. The method is based on the strong blue-colored complexes formed between iron(III) and tiron. The absorbance of the complexes is measured spectrophotometrically at 635 nm. Oxidation of iron(II) and masking of interfering fluoride is simultaneously done by injecting one zone of hydrogen peroxide and one of thorium(IV) between the sample and reagent zones. Concentration of iron(III) and total iron, in the range 0.002–0.026 M, in diluted samples from a pickle bath were determined. The relative standard deviation was 0.4% (n=7). The method was also used in a pilot plant of a zinc process for determination of iron(III) in the range 0.2–3.0 g l⁻¹. The sample throughput is approximately 17 samples per hour, including three repetitive determinations of each sample.     

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).     

Spectrophotometric determination of trace amounts of iron(III) with norfloxacin as complexing reagent

The complexation of iron(III) with norfloxacin in acidic solution at 25 degrees C, at an ionic strength of about 0.3 M and a pH of 3.0 has been studied. The water-soluble complex formed, which exhibits an absorption maximum at 377 nm, was used for the spectrophotometric determination of trace amounts of iron(III). The molar absorptivity was 9.05 x 10(3) I mol-1 cm-1 and the Sandell sensitivity 6.2 ng cm-2 of iron(III) per 0.001 A. The formation constant (Kf) was determined spectrophotometrically and was found to be 4.0 x 10(8) at 25 degrees C. The calibration graph was rectilinear over the range 0.25-12.0 p.p.m. of iron(III) and the regression line equation was A = 0.163c - 0.00042 with a correlation coefficient of 0.9998 (n = 9). Common cations, except cerium (IV), did not interfere with the determination. The results obtained for the determination of iron(III) using the described procedure and the thiocyanate method were compared statistically by means of the Student t-test and no significant difference was found.     

Spectrophotometric determination of iron(III) with o-hydroxyhydroquinonephthalein after preconcentration on a membrane filter

Application of xanthene derivatives in analytical chemistry. Part LXXXVIII. Part LXXXVII see ref. [1]     

Spectrophotometric determination of ziram, ferbam and zineb with diphenylcarbazone

A procedure has been developed for the determination of ziram (zinc dimethyldithiocarbamate), ferbam (ferric dimethyldithiocarbamate) and zineb (zinc ethylenebisdithiocarbamate) after their decomposition and extraction of the diphenylcarbazone complexes of the zinc or iron into isobutyl methyl ketone. These complexes absorb strongly at 520 nm. The method is rapid, sensitive and selective and can be used for the determination of these dithiocarbamates in commercial and synthetic mixtures.     

Photometric determination of iron (III)

A sensitive colored reaction of tiron with iron (III) is described. It is based on a complex formation between tiron and iron (III) in basic medium. The method is suitable to determine 0.4–10 ppm of iron (III) with a relative standard deviation of 0.45–1.4% depending on the concentration level, molar absorptivity of 5.7 × 10³ liter mol⁻¹ cm⁻¹, and Sandell sensitivity index of 0.0098 μg/cm².Because of being simple and rapid, this method can certainly be used in routine analysis.     

Spectrophotometric determination of ruthenium(III) using diphenylcarbazone

Summary The purple violet ruthenium(III)-diphenylcarbazone complex which is formed at p _h 5–7, and has an absorption maximum at 530 nm with molar absorption coefficient 16.2·10⁴l.cm^–1.mole^–1 is suggested for the estimation of 20–125g ruthenium(III) spectrophotometrically in 30–60% ethanol. The complex is stable over p _h range 3.2–8.4. The limits of interference due to foreign ions have been studied.

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Zusammenfassung Der bei p _h 5 bis7 entstehende Ruthenium(III)-Diphenylcarbazon-Komplex hat ein Absorptionsmaximum bei 530 nm und einen Absorptionskoeffizienten von 16,2·10⁴ l.cm^–1.Mol^–1. Die spektrophotometrische Bestimmung von 20 bis 125g Ruthenium(III) in 30 bis 60%igem Äthanol mit Hilfe dieses zwischen p _h 3,2 und 8,4 beständigen Komplexes wurde vorgeschlagen. Die Störung durch Fremdionen wurde geprüft.

     

Spectrophotometric determination of iron (II) with quinisatin oxime

A sensitive spectrophotometric determination of iron is based on the blue color (absorption maximum at 660 mμ) formed by reaction of iron (II) with quinisatin oxime in buffered solution containing ethyl alcohol and a small amount of dimethylformamide. The color develops rapidly and is stable for a few h. The absorbance is well reproducible, and conforms to Beer's law. The optimum concentration range at 1 cm optical path is about 0.5 to 2.5 p.p.m. of iron. Small amounts of iron(III) are reduced by the reagent and cause no difficulty. Cobalt and nickel interfere. Iron(II) and quinisatin oxime react in a 1:3 mole ratio; some possible modes of complex formation are suggested.     

Spectrophotometric determination of trace amounts of iron(III) by extraction of the mixed-ligand iron-fluoride-purpurin complex

The characteristics of the mixed-ligand iron(III)-fluoride-purpurin complex, including optimum conditions of formation and extraction into methyl isobutyl ketone are described. A procedure for determination of trace amounts of iron in fluoride medium (0.5M) with purpurin (1,2,4,-trihydroxy-anthraquinone) in methyl isobutyl ketone is given. The method is suitable for determining iron in the presence of large amounts of aluminium, cyanide, phosphate and nickel.     

Spectrophotometric determination of vanadium as V(III) oxinate

Vanadium(V) is rapidly reduced by dithionite to V(III) which is extracted as the oxinate into carbon tetrachloride. Vanadium is determined by measuring absorbance of the complex at lambda(max) = 420-425 nm with a sensitivity of 0.004 microg/cm(2) and Beer's law range of 0-7 microg/ml . Several mg of some important elements can be tolerated if they are masked. Molybdenum interferes seriously. The method has been applied to synthetic samples, rutile and ilmenite with satisfactory results. Using ordinary reagents and taking 10 min or less in series for a determination, the method has a sensitivity rarely exceeded by others with a much higher tolerance for other elements.     

Spectrophotometric determination of chromium(III) with 2-hydroxybenzaldiminoglycine

A spectrophotometric method employing 2-hydroxybenzaldiminoglycine is proposed for the determination of chromium(III). The results of the determinations are compared with those obtained by the standard diphenyl carbazide method. The presently developed method is direct, simple, rapid, selective, sensitive and precise. The text was submitted by the authors in English.