The Spectrophotometric Determination of gallium (III) Using O-Hydroxyhydroquinonephathalein in the Presence of Surfactant Micellar

Abstract

The color reaction systems between various metal ions and o-hydroxyhydroquinonephthalein(Qnph) as a xanthene dye, in the presence of various water soluble surfactants(cationic. anionic, non-ionic surfactants) alone or in combination, were systematically investigated at various pH areas. The coexistence of cationic and non-ionic surfactants, such as Zephiramine (Zp) and Brij 35, was most effective for the color reaction systems between Qnph and gallium(III), as a metal ion, at weakly acidic media. By using the color reaction between Qnph and gallium(III) in the coexistence of Zp and Brij 35, an improved and sensitive spectrophotometric determination of gallium(III) was proposed as method 1, and the calibration curve was rectilinear in the range of 0～7.0 μg of gallium(III) in a final solution of 10ml at pH 6.4. The apparent molar absorptivity was 1.5 × 10⁵ 1 mol^?1 cm^?1 at 560 nm, and the interference of foreign ions was decreased by ½～ ¼-fold in comparison with other methods; method 3—in the presence of Zp alone at pH 6.4, method 2—in the presence of Tween or Brij 35 alone, without Zp, at pH 8. Thus, the use of Qnph as a xanthene dye and the combination of cationic and non-ionic surfactants, such as Zp and Brij 35(perhaps, on the mixed micellar media), was most effective and its color reaction was used for the separative assay of gallium(III).     

Fluorimetric determination of iron(III) by quenching the luminescence of the zinc-morin-Triton X-100 system

Summary Simple and highly sensitive fluorimetric methods for iron determination are described. The methods are based on quenching the fluorescence of an aqueous morin solution or zinc-morin-Triton X-100 ternary system. The fluorescence emission is measured at 500 and 503 nm (wavelength of excitation 420 and 433 nm) for morin and the ternary system, respectively. The quenching calibration graphs are linear over the range 0–250 and 0–55 ng Fe/ml and the iron detection limits are 20 and 5 ng/ml using morin and zinc-morin-Triton X-100 system, respectively. The influence of experimental variables such as pH, reagent and surfactant concentrations, temperature, standing time and diverse ions are studied to obtain the optimum conditions. The method has been applied to the determination of iron in aluminium metal.

---

Fluorimetrische Eisen(III)-bestimmung durch Luminescenzlöschung des Systems Zink-Morin-Triton X-100

     

Spectrophotometric Determination of Gadolinium(III) With O-Hydroxyhydroqoinonephthalein in Mixed Micelles of N-Hexadecylpyridinilm Chloride and Brij 35

Abstract

A sensitive, simple and selective spectrophotometric method for the determination of gadolinium(III) is proposed using o-hydroxyhydroquinonephthalein(Qnph), by analogy with phenylfl-uorone(Phfl), in the presence of N-hexadecylpyridinium chlo-ride(HPC)-Brij 35 mixed surfactants. The calibration curve is rectilinear in the range of 0 – 16.0 μg per 10 ml at 590 nm with an apparent absorption coefficient(?) of 1.2 × 10⁵ 1 cm^?1 mol^?1 and Sandell sensitivity of 0.0013 μg/cm² gado-linium(III).     

Spectrophotometric Determination of Nickel(II) with O-hydroxyhydroquinonephthalein in the Mixed Micellar Media of Zephiramine and Tween 20

Abstract

The effect of mixed surfactants on the color reaction between nickel(II) and o-hydroxyhydroquinonephthalein(Qnph) was examined in weakly basic media. The color development of the metal complex in the presence of cationic and nonionic surfactants (mixed micellar media of Zephiramine (Zp) and Tween 20) was very stable and exhibited a high and reproducible absorbance. The calibration curve was linear in the ranges of 0 – 7.0 μg nickel(I1) in a final volume of 10 ml at 545 or 536 nm. The method developed does not require an organic solvent extraction step. The apparent molar absorptivity and Sandell sensitivity were 1.26 × 10⁵ 1 per mol per crn and 0.0045 μg per cmL nickel(II), respectively, at 545 nm.     

Catalytic effect of iron(III) on the oxidation of 2-hydroxybenzaldehyde thiosemicarbazone by hydrogen peroxide : Kinetic Fluorimetric Determination of Iron

A kinetic method is described for the determination of nanogram amounts of iron(III) based on its catalysis of the oxidation of 2-hydroxybenzaldehyde thiosemicarbazone by hydrogen peroxide in an ammoniacal medium. In order to monitor the reaction, the appearance rate of fluorescence of the oxidation product (λ_ex=365 nm, λ_em=440 nm) is measured. The calibration graph is linear in the range 10–60 ng ml^?1 iron(III) with an r.s.d, of ± 1.3%. The proposed method has few interferences and has been applied satisfactorily to the determination of iron in several alloys and minerals. A mechanism for the catalyzed reaction is proposed.     

Zero-Order and Third-Derivative Spectrophotometric Determination of Iron(III) with 4-(2-Pyridylazo)-Resorcinol in the Presence of N-Hexadecylpyridinium Chloride

Abstract

The complex formation reaction between iron(III) and 4-(2-pyridylazo) resorcinol(PAR) in the presence of various water soluble surfactants((N-hexadecylpyridinium chloride (HPC), poly(vinylalcohol)(PVA), sodium dodecylsulfate(SDS), sodium N-lauroylsarcosine(SL)) alone or in combination at weakly acidic media was systematically investigated. An improved and more sensitive spectrophotometric method for the determination of iron was proposed by zero-order and third-derivative spectrophotometry using the PAR-iron(III)-HPC ternary complex system at about pH 5.2. The calibration curve was rectilinear in the ranges of 0 – 15.0 μg iron(III) in a final 10-ml on the zero-order spectrophotometry. Also, upon the third-derivative spectrophotometry, Beer's law was obeyed in the range of 0 – 8.0 μg iron(III)/10 ml by measuring the distance between the absorbance peak(λ₁ = 527 nm) and the valley (λ₂ = 560 nm). The apparent molar absorptivity was 4.8 × 10⁴ 1 mol^?1 cm^?1 in zero-order spectrophotometry, and 1.36 × 10⁵ mol^?1 cm^?1 in third-derivative spectrophotometry. The effect of foreign ions was decreased within ½ – ¼-fold in comparison with the method in the presence of PVA without HPC. Especially, the third-derivative spectrophotometric method was sensitive and selective, and made possible to assay mixed sample solution containing iron(III) and copper(II), etc.     

Flow-injection determination of copper(II) based on its catalysis on the redox reaction of cysteine with iron(III) in the presence of 1,10-phenanthroline

A redox reaction of cysteine with iron(III) proceeds slowly in the presence of 1,10-phenanthroline (phen). However, this reaction is accelerated in the presence of copper(II) as a catalyst, producing an iron(II)-phen complex (lambda(max)=510 nm). A sensitive spectrophotometric flow-injection method is proposed for the determination of copper(II) based on its catalytic action on this redox reaction. The dynamic range was 0.1-10 ng ml(-1) of copper(II) with a relative standard deviation of 1.0% (n=10) for 1.0 ng ml(-1) of copper(II) at a sampling rate of 30 h(-1). The detection limit (S/N=3) is 0.04 ng ml(-1). The proposed method was successfully applied to the determination of copper in river water as a certified reference material.     

Catalytic kinetic spectrophotometric determination of iron with (dibromo-<Emphasis Type="Italic">p</Emphasis>-sulfonic acid arsenazo)-potassium bromate-ascorbic acid system

A new method for the determination of traces of iron was developed based on its catalytic effect on the oxidation reaction of dibromo-p-sulfonic acid-arsenazo (DBS-arsenazo, DBS-ASA) by potassium bromate in a 5.0 × 10⁻³ M sulfuric acid medium. The optimum experimental conditions for the determination of iron using iron(III)-dibromo-p-sulfonic acid-arsenazo, (DBS-ASA)-potassium bromate-ascorbic acid system and its kinetic spectrophotometric properties were studied. The absorbance difference (ΔA) is linearly related with the concentration of iron(III) over the range of 0.20–6.0 ng/mL at the maximum absorption wavelength of 520 nm and described by the equation: ΔA = 0.133c (ng/mL) — 0.0133 with a regression coefficient of 0.9966. The detection limit of the method is 0.17 ng/mL. The method has been successfully used in the determination of traces of iron in potato samples. The obtained results agree with those of atomic absorption spectrometry.     

Determination of trace amounts of vanadium with a new reagent [1-(3-methoxysalicylidene-amino)-8-hydroxy-3,6-naphthalene disulfonic acid, disodium salt] by fluorescence quenching method

A fluorescence quenching method is described for the determination of trace amounts of vanadium(V) based on the formation of a complex in acidic medium with a new reagent [1(3-methoxysalicylideneamino)-8-hydroxy-3,6-naphthalene disulfonic acid, disodium salt]. The fluorescence emission is measured at 415 nm (wavelength of excitation 360 nm), and the experimental variables and interferences in this determination have been studied. The detection limit is 12.5 ng/ml and linear range is between 50 and 600 ng/ml. The method has been applied to determine trace vanadium(V) in steel and cast iron.     

Kinetic- and catalytic-spectrophotometric determination of iron by pyrogallolphthalein and potassium perdisulphate in non-ionic surfactant micellar medium

Summary A simple and highly sensitive spectrophotometric determination of iron with pyrogallolphthalein in a micellar medium of non-ionic surfactant is proposed. This method is based on the kinetic-catalytic action of iron(III) upon the decomposition reaction between pyrogallolphthalein and potassium perdisulphate at pH 2.4–2.9 in the presence of Triton X 100 as a non-ionic surfactant. The calibration graph is linear over the range 10–600 ng iron(III) per 10 ml in spectrophotometry (apparent molar absorption coefficient for decomposition was 1.25×10^–6 l per mole per cm at 385 nm). The method was applied to assay and recovery tests for artificial waste water with satisfactory results (recovery 97.6%–103.5%).

---

Kinetische und katalytisch-spektralphotometrische Eisenbestimmung mit Hilfe von Pyrogallolphthalein und Kaliumperdisulfat in Gegenwart eines nichtionischen Tensids

---

Application of xanthene derivatives in analytical chemistry. Part LXXV. Part LXXIV see ref. [1]     

2.2 Organic industrial products

Summary Highly sensitive and selective spectrofluoriphotometric determinations of iron(III) with fluorescein(Fl)-hydrogen peroxide-triethylenetetramine (TETA), and manganese(II) with Fl-hydrogen peroxide-TETA-tiron are proposed. The methods are based on the inhibition of the oxidizing decomposition of Fl-hydrogen peroxide solution in the presence of iron(III)-TETA or manganese(II)-TETA-tiron combination. The calibration graphs are linear in the ranges of up to 220 ng iron(III) and up to 270 ng manganese(II) per 25 ml at an emission wavelength of 510 nm with excitation at 490 nm. By measuring the difference of relative fluorescence intensities (F) between Fl-TETA-hydrogen peroxide and its iron(III) solutions or Fl-TETA-tiron-hydrogen peroxide and its manganese(II) solutions, the concentrations of iron(III) or manganese(II) are determined. The application of these methods to the analysis of iron(III) or manganese(II) in waste water was investigated with satisfactory results.

---

Hochempfindliche und selektive fluorimetrische Bestimmungsmethoden für Eisen(III) und Mangan(II) mit Fluorescein/H₂O₂/Triethylentetramin bzw. Fluorescein/H₂O₂/Triethylentetramin/Tiron

---

Application of xanthene derivatives in analytical chemistry. Part LXXVIII. Part LXXVII see ref. [1]     

Coprecipitative Preconcentration and Differential Pulse Cathodic Stripping Voltammetric Determination of Selenium (IV)

Abstract

A DPCSV procedure for the determination of selenium (IV) with a prior preconcentrative coprecipitation on iron (III) hydroxide has been developed. The experimental conditions for coprecipitation of selenium (IV) onto iron (III) hydroxide, viz. pH, iron (III) concentration, volume of aqueous phase and selenium concentration, were optimized. The coprecipitated selenium (IV) is dissolved in 10 ml of 0.1 M HCl and analysed using DPCSV in the presence of copper (II). Selenium concentrations as low as 10–100 ng present in 500 ml of the aqueous phase could be determined. The method is precise and has been applied to the analysis of sea water and reference material samples.     

Fluorometric determination of uranium and tungsten with o-hydroxyhydroquinonephthalein in the presence of non-ionic surfactant

Complex formation between uranium or tungsten and o-hydroxyhydroquinonephthalein (Qnph) in various micellar surfactant media has been investigated fluorometrically, and determination of uranium and tungsten based on the difference between the relative fluorescence intensities of Qnph and the metal complex at 535 nm, with excitation at 400 nm in the presence of poly(vinyl) alcohol as a non-ionic surfactant. The calibration curves were linear up to 1.0 mu/ml uranium and 0.9, mu/ml tungsten. The relative standard deviations (5 replicates) were 2.6% for tungsten and 3.0% for uranium, and recovery tests gave relatively good results (97-104%).     

Flow injection spectrofluorimetric determination of iron(III) in water using salicylic acid

A simple and fast flow injection fluorescence quenching method for the determination of iron in water has been developed. Fluorimetric determination is based on the measurement of the quenching effect of iron on salicylic acid fluorescence. An emission peak of salicylic acid in aqueous solution occurs at 409 nm with excitation at 299 nm. The carrier solution used was 2 × 10⁻⁶ mol L⁻¹ salicylic acid in 0.1 mol L⁻¹ NH₄⁺/NH₃ buffer solution at pH 8.5. Linear calibration was obtained for 5–100 μg L⁻¹ iron(III) and the relative standard deviation was 1.25 % (n = 5) for a 20 μL injection volume iron(III). The limit of detection was 0.3 μg L⁻¹ and the sampling rate was 60 h⁻¹. The effect of interferences from various metals and anions commonly present in water was also studied. The method was successfully applied to the determination of low levels of iron in real samples (river, sea, and spring waters).     

Spectrophotometric determination of antimony with vanillylfluorone in the presence of poly(vinyl alcohol)

Antimony in the range up to 2.5 mug/ml in the final solution is determined spectrophotometrically with vanillylfluorone in the presence of poly(vinyl alcohol) in acidic media. The method is compared with that using o-hydroxyhydroquinonephthalein (Qnph). It is simple, rapid and sensitive, without need for heating or solvent extraction, and the apparent molar absorptivity () is 5.0 x 10(4) 1.mole(-1).cm(-1) at 545 nm; for the Qnph method is 2.8 x 10(4) 1.mole(-1).cm(-1) at 520 nm. Tests with an artificial wastewater gave 99-103% recovery.     

A New Kinetic-Fluorimetric Method for the Determination of Silver Based on Its Inhibitory Effect on the Oxidation of 2-Hydroxybenzaldehyde Thiosemicarbazone with Hydrogen Peroxide Catalyzed by Iron (III)

Abstract

An indirect kinetic determination of silver based on its inhibitory effect on the oxidation of 2-hydroxybenzaldehyde thiosemicarbazone with hydrogen peroxide catalyzed by iron (III) is described. The reaction is followed spectrofluorimetrically by measurement of the initial rate at the wavelengths of the oxidation product (λ_exc=365nm, λ_em=440nm.). The calibration curves are linear between 50-400 ng.ml^?1 of silver with a precision of ± 2.3%. The proposed method has few interferences.     

Fluorimetric Determination of Trace Amounts of Scandium with Di-2-pyridyl-ketone 2-Furoylhydrazone

Abstract

The reaction of Di-2-pyridyl-ketone 2-furoylhydrazone (DPFH) with scandium in an aqueous ethanolic medium (4% v/v of ethanol) has been studied. A spectrofluorimetric method based on the formation of a fluorescent complex is proposed for the determination of scandium. With excitation at 387 nm, the scandium (III) chelate has an emission maximum at 492 nm; the reaction is carried out at pH 6.5–7.5. The accuracy and precision of the method are demonstrated by the analysis of synthetic mixtures containing various amounts of scandium. 10 – 140 ng/ml of scandium can be determined with a relative error of ±1.3%.     

Determination of nucleic acids using calcein-neodymium complex as a fluorescence probe.

A novel fluorometric method has been developed for rapid determination of DNA and RNA with calcein-neodymium complex as a fluorescence probe. The method is based on the fluorescence enhancement of calcein-Nd(III) complex in the presence of DNA or RNA, with maximum excitation and emission wavelength at 489 nm and 514 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.5 - 3.0 microg/ml for both DNA and yeast RNA, 0.4 - 2.0 microg/ml for fish sperm DNA (FS DNA) and 0 - 3.0 microg/ml for calf thymus DNA (CT DNA). The corresponding detection limits are 15.1 ng/ml for DNA, 21.2 ng/ml for yeast RNA, 10.5 ng/ml for FS DNA and 8.9 ng/ml for CT DNA. The interaction mechanism for the binding of calcein-Nd(III) complex to DNA is also studied. The results of absorption spectra, fluorescence polarization measurements and thermal denaturation experiments, suggested that the interaction between calcein-Nd(III) complex and DNA is an electrostatic interaction.     

A Fluorescence Quenching Method for the Determination of Bromate Ion with 4,5-Dibromophenylfluorone and Cetyltrimethylammonium Bromide

Abstract

A highly sensitive and selective fluorescence quenching method was developed to determine the bromate ion (BrO₃ ^?) with 4,5-dibromophenylfluorone (DB-PF) as fluorogenic reagent. BrO₃ ^? reacts with potassium bromide in sulfuric acid solution (0.6M) giving bromine (Br₂) which is estimated with fluorescence quenching method using DB-PF as fluorogenic reagent. Bromine reacts with DB-PF to produce a compound, whose maximum excitation wavelength and emission wavelength are 543nm, 560nm respectively. The linear calibration range is 0.05–0.5 μg/25ml. The detection limit is 0.05μg/25ml. The method may be used to determine microamounts of BrO₃ ^? in potassium chlorate with satisfactory results. The method offers the advantages of simplicity, rapidity and sensitivity.     

Flow injection determination of iron by its catalytic effect on the oxidation of 3,3',5,5'-tetramethylbenzidine by hydrogen peroxide

A flow injection-photometric method has been developed for the determination of iron(II+III). The method is based on the catalytic effect of iron(III) on the hydrogen peroxide oxidation of 3,3',5,5'-tetramethylbenzidine to form a blue compound (lambda(max)=650 nm). In this catalyzed reaction, 1,10-phenanthroline acted as an effective activator. Iron(II) is also determined, being oxidized by hydrogen peroxide. Calibration graphs for iron(II) and iron(III) obtained under the optimized conditions were identical with each other and linear in the range 0.2-200 ng ml(-1) with a detection limit of 0.05 ng ml(-1) iron. The reproducibility was satisfactory with a relative S.D. of 1.0% for ten determinations of 5 ng ml(-1) iron(III). The proposed method was successfully applied to the determination of iron in river and lake water samples and can be determined free iron species.