Spectrophotometric Determination Of Iron Research Articles

Spectrophotometric Determination of Iron as lron(II) Thiocyanate Cetyltrimethylammonium Bromide

Spectrophotometric Determination of Iron as lron(II) Thiocyanate Cetyltrimethylammonium Bromide

Simple Spectrophotometric Determination of Iron in Diesel Oil after Sample Preparation Employing Extraction Induced by Emulsion Breaking

This work reports the development of a simple and fast method for the spectrophotometric determination of Fe in diesel oil using the classic reaction with 1,10-phenanthroline after its extraction induced by emulsion breaking (EIEB). The extraction parameters of EIEB were optimized (concentration of HNO3 and Triton X-100® in the emulsifying solution) as well as the adjustment of the pH of the final solution, a necessary step to complete the colorimetric reaction. The developed method presented a limit of detection of 0.004 mg L–1 and a limit of quantification of 0.013 mg L–1 and was applied in the analysis of six samples of diesel oil with different specifications. The results were statistically similar to those obtained by graphite furnace atomic absorption spectrometry (GF AAS). A recovery test was also performed by spiking the samples with 1.0 mg L–1 of Fe in the form of an organometallic compound, yielding recovery percentages between 83 and 108%.

Spectrophotometric Determination of Fe(II) and Fe(III) Using 5-(4-Ethylphenyl azo ) 2-Hydroxybenzaldehyde Oxime Reagent

Spectrophotometric Determination of Fe(II) and Fe(III) Using 5-(4-Ethylphenyl azo ) 2-Hydroxybenzaldehyde Oxime Reagent

部分的最小二乗法によるフローインジェクション分析の迅速化—フェナントロリン吸光光度法を用いる鉄の定量による検証—

部分的最小二乗法によるフローインジェクション分析の迅速化—フェナントロリン吸光光度法を用いる鉄の定量による検証—

Micelle-mediated extraction for speciation and spectrophotometric determination of iron using a newly synthesized salicylic acid derivative

A sensitive and selective method for speciation and determination of iron was developed using cloud point extraction combined with spectrophotometry. The method depends on formation of complex between Fe3+ and a newly synthesized reagent, 4-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxybenzoic acid (DOPHHBA), and its extraction into Triton X-114 rich phase prior to spectrophotometric determination at 438 nm. Total Fe was determined as Fe3+ by the same methodology after oxidation of Fe2+. The method exhibited dynamic linear range from 4.0 to 500 µg L-1 with limit of detection and enrichment factor of 1.2 µg L-1 and 95.2, respectively. The accuracy of the method was tested by analysis of certified reference materials and spiked samples. The method was applied for speciation of Fe in natural water samples and determination of Fe in food samples with satisfying results. The analytical results are statistically comparable with those obtained by a standard ICP-OES method.

Novel Cyclic Voltammetry Behavior Of 3-((Benzothiazol-2-Diazenylnaphthalene-2,7-Diol And Use It For Spectrophotometric Determination Of Iron (III )In Blood Sample

The azo reagent 3-((benzothiazol-2-diazenylnaphthalene-2,7-diol] was synthesized and characterized by FT-IR, 1H-NMR and 13CNMR spectral techniques. The electrochemical behavior of the azo reagent and its complex with Fe (III) has been studied at glassy carbon disk GCE electrode in different supporting electrolyte at concentration (1M) and scan rate (100mvs-1). Spectrophotometric determination of Iron (III ) is based on the formation of a 2:1 complex with above reagent. The complex has λmax at (576) nm and εmax of( 1.6451*104)L.mol-1.cm-1. A linear correlation (0.1 – 4.0 μg. ml-1) was found between absorbance at λmax and concentration. The effect of diverse ions on the determination of Iron (III) to investigate the selectivity of the method were also studied. The stability constant of the product was (3.098*108 ). The proposed method was successfully applied to the analysis of blood samples

Mixed Micellar Cloud Point Extraction and Spectrophotometric Determination of Iron(II) Using 1,10-Phenanthroline: Effect of Sodium Nitroprusside on Extraction Efficiency

Mixed Micellar Cloud Point Extraction and Spectrophotometric Determination of Iron(II) Using 1,10-Phenanthroline: Effect of Sodium Nitroprusside on Extraction Efficiency

Second Derivative Spectrophotometric Determination of Iron(II) and Ruthenium(III) Using 1, 10-phenanthroline

A simple and sensitive derivative spectrophotometric method has been developed for the determination of Fe(II) and Ru(III) using the baseline to peak measurement techniques. In the present method 1,10-phenanthroline (o-phen) used as a complexing agent. Fe(II) and Ru(III) forms a complex with o-phen at pH 5 and 4, respectively. Based on baseline-to-peak measurement techniques deep red Fe(II)-o-phen complex shows the maximum peak at 535 nm, while the yellow product of Ru(II) - o-phen complex at 466 nm. Beer's law obeyed in the range of 0.1 - 2.0 μg mL-1 for Fe(II) and 5.0 - 20.0 μg mL-1 for Ru(III) which is supported by correlation coefficient 0.99853 and 0.99914, respectively. The present method has been applied successfully for the determination of Fe (II) in pharmaceutical formulations and Ru(III) in some synthetic mixtures.

Separation and Spectrophotometric Determination of Iron (III) and Mercury (II) via Cloud Point Extraction with New Azo-Derivative

Separation and Spectrophotometric Determination of Iron (III) and Mercury (II) via Cloud Point Extraction with New Azo-Derivative

Halloysite Nanotubes as a New Adsorbent for Solid Phase Extraction and Spectrophotometric Determination of Iron in Water and Food Samples

Halloysite nanotubes (HNTs) have been introduced as a new solid phase extraction adsorbent for preconcentration of iron(II) as a complex with 2,2-bipyridine. The cationic complex is effectively adsorbed on the sorbent in the pH range of 3.5–6.0 and efficiently desorbed by trichloroacetic acid. The eluted complex has a strong absorption around 520 nm, which was used for determination of Fe(II). After optimizing extraction conditions, the linear range of the calibration graph was 5.0–500 μg/L with a detection limit of 1.3 μg/L. The proposed method was successfully applied for the determination of trace iron in various water and food samples, and the accuracy was assessed through the recovery experiments and analysis of a certified reference material (NIST 1643e).

Analytical Application of 1, 1′-(Sulfonyldibenzene-4,1-diyl)bis(3-hydroxy-3-phenyltriaz-1-en) (BHDPT) in the Spectrophotometric Determination of Iron (III)

Bis hydroxytriazenes (1, 1′-(sulfonyldibenzene-4,1-diyl)bis(3-hydroxy-3-phenyltriaz-1-en)) has been proposed as a sensitive and selective reagent for the spectrophotometric determination of Iron(III). The method is based on the formation of green coloured 1:1 complex by the reaction of Iron (III) with Bis hydroxytriazenes. Beer's law is valid over the concentration range of 1×10−4 to 4.5×10−4. The coloured complex exhibit an absorption maximum at 410 nm with molar absorptivity of 45606.2 L mol−1cm−1 and sendell sensitivity of 1.22 ng cm−2 the absorbance is found to increase linearly with increase in concentration of iron which are corroborated by the calculated correlation coefficient.

Spectrophotometric determination of iron and copper ions in industrial wastewater, cooling water and scale of power station

AbstractSensitive and selective spectrophotometric procedures were proposed for the determination of Fe(III) and Cu(II) using simple chromogenic reagents. The procedure of iron determination was based on the formation of ternary complex between Fe(III) and 4,7-diphenyl-1,10-bathophenanthroline (DPBP)–eosin in acid medium. On the other hand, the procedure of copper (II) determination was based on the formation of ternary complex between Cu(II) and 4,7-diphenyl-1,10-bathophenanthroline (DPBP)–Eriochrome Black-T (EBT) in alkaline medium. The ternary complexes were extracted in the presence of cetyltrimethyl ammonium bromide with chloroform. The molar absorptivities of the Fe(III)–DPBP–eosin and Cu(II)–DPBP–EBT ternary complexes were 2.23 · 105 and 9.35 · 104 L mol−1 cm−1 at 542 and 565 nm, respectively. Beer’s law is valid over the concentration ranges from 0.280 to 7.814 and from 0.320 to 8.260 μg mL−1 for Fe(III) and Cu(II), respectively. Sandell sensitivity (0.0025 and 0.0679 ng cm−2), relative standard d...

An improved approach for flow-based cloud point extraction

Novel strategies are proposed to circumvent the main drawbacks of flow-based cloud point extraction (CPE). The surfactant-rich phase (SRP) was directly retained into the optical path of the spectrophotometric cell, thus avoiding its dilution previously to the measurement and yielding higher sensitivity. Solenoid micro-pumps were exploited to improve mixing by the pulsed flow and also to modulate the flow-rate for retention and removal of the SRP, thus avoiding the elution step, often carried out with organic solvents. The heat released and the increase of the salt concentration provided by an on-line neutralization reaction were exploited to induce the cloud point without an external heating device. These innovations were demonstrated by the spectrophotometric determination of iron, yielding a linear response from 10 to 200μgL−1 with a coefficient of variation of 2.3% (n=7). Detection limit and sampling rate were estimated at 5μgL−1 (95% confidence level) and 26 samples per hour, respectively. The enrichment factor was 8.9 and the procedure consumed only 6μg of TAN and 390μg of Triton X-114 per determination. At the 95% confidence level, the results obtained for freshwater samples agreed with the reference procedure and those obtained for digests of bovine muscle, rice flour, brown bread and tort lobster agreed with the certified reference values. The proposed procedure thus shows advantages in relation to previously proposed approaches for flow-based CPE, being a fast and environmental friendly alternative for on-line separation and pre-concentration.

Spectrophotometric determination of iron in environmental and food samples using solid phase extraction

A simple, selective and highly sensitive extraction method has been developed for the determination of iron(II) spectrophotometrically after solid phase extraction. The absorbance is measured at λmax 644nm. Beer’s law was obeyed up to 450ngmL−1 of iron. The molar absorptivity, Sandell’s sensitivity, detection and quantification limits were calculated and found to be 1.09×105Lmol−1cm−1, 0.51ngcm−2, 1.98 and 6.0ngmL−1, respectively and compared with parameters obtained without using solid phase extraction method. After reduction of Fe(III) by addition of 2.0mL of 10% hydroxylamine HCl, the system was applied to the total iron. The interference of various ions has been studied in detail and the statistical evaluation of the experimental results is reported. The proposed methods have been successfully applied for the determination of trace amount of iron in environment water, soil and botanical reference materials with recovery range (98.71–101.51%).

Determination of iron in milk infant formulas by using Chromazurol S in the presence of dodecyltrimethylammonium bromide and Brij 35

Two sensitive methods for spectrophotometric determination of iron(III) in milk infant formulas, based on the formation of coloured complexes of Fe(III) with Chromazurol S (CAS) in the presence of dodecyltrimethylammonium bromide (DTA) alone and DTA with Brij 35 have been developed. Optimum pH and the concentrations of CAS, DTA, and Brij 35 ensuring maximum absorbance have been determined. For the Fe-CAS-DTA system, the molar absorptivity is 1.05 × 105 L/(mol cm) at 685 nm; for Fe-CAS-DTA-Brij 35 it is 1.94 × 105 L/(mol cm) at 636 nm. Beer’s law was obeyed for iron concentration in the range of 0.04–0.40 μg/mL for the complex Fe-CAS-DTA and 0.08−0.40 μg/mL for Fe-CAS-DTA-Brij 35. The influence of several interfering ions has been discussed. The stoichiometry of the complexes was established by applying Job’s method. The method, basing on the Fe-CAS-DTA system, has been applied to the determination of iron in milk samples. To evaluate the accuracy of the elaborated method, the determined content of Fe was compared to the declared value as well as to the result obtained by the reference ICP-OES method.

2, 2′-ジピリジルとテトラフェニルホウ酸イオンを担持させたナフタレンを吸着剤とするカラム分離濃縮法による海水および食塩中の鉄め吸光光度定量

2, 2′-ジピリジルとテトラフェニルホウ酸イオンを担持させたナフタレンを吸着剤とするカラム分離濃縮法による海水および食塩中の鉄め吸光光度定量

Uso de hardware de código fonte aberto "Arduino" para acionamento de dispositivo solenoide em sistemas de análises em fluxo

This paper describes the use of the open source hardware platform, denominated Arduino, for controlling solenoid valves for solutions handling in flow analysis systems. System assessment was carried out by spectrophotometric determination of iron (II) in natural water. The sampling rate was estimated as 45 determinations per hour and the coefficient of variation was lower than 3%. Per determination, 208 µg of 1-10-phenanthroline and ascorbic acid were consumed, generating 1.3 mL of waste. Arduino proved a reliable microcontroller with low cost and simple interfacing, allowing USB communication for solenoid device switching in flow systems.

Spectrophotometric Determination of Iron(II) after Solid Phase Extraction of Its 2,2′ Bipyridine Complex on Silica Gel-Polyethylene Glycol

A new solid phase extraction procedure was developed for preconcentration of iron(II) using silica gel-polyethylene glycol (silica-PEG) as an adsorbent. The method is based on retention of iron(II) as 2,2′ bipyridine complex on silica-PEG. The retained complex is eluted by 1.0 mol L−1of sulfuric acid-acetone mixture (1:2) and its absorbance is measured at 518 nm, spectrophotometrically. The effects of different parameters such as pH, concentration of the reagent, eluting reagent, sample volume, amount of adsorbent, and interfering ions were investigated. The calibration graph was linear in the range of 1–60 ng mL−1of iron(II). The limit of detection based on3Sbwas 0.57 ng mL−1and relative standard deviations (R.S.D) for ten replicate measurements of 12 and 42 ng mL−1of iron(II) were 2.4 and 1.7%, respectively. The method was applied to the determination of of iron(II) in water, multivitamin tablet, and spinach samples.

Spectrophotometric Determination of Iron(II) and Cobalt(II) by Direct, Derivative, and Simultaneous Methods Using 2-Hydroxy-1-Naphthaldehyde-p-Hydroxybenzoichydrazone.

Optimized and validated spectrophotometric methods have been proposed for the determination of iron and cobalt individually and simultaneously. 2-hydroxy-1-naphthaldehyde-p-hydroxybenzoichydrazone (HNAHBH) reacts with iron(II) and cobalt(II) to form reddish-brown and yellow-coloured [Fe(II)-HNAHBH] and [Co(II)-HNAHBH] complexes, respectively. The maximum absorbance of these complexes was found at 405 nm and 425 nm, respectively. For [Fe(II)-HNAHBH], Beer's law is obeyed over the concentration range of 0.055–1.373 μg mL−1 with a detection limit of 0.095 μg mL−1 and molar absorptivity ɛ, 5.6 × 104 L mol−1 cm−1. [Co(II)-HNAHBH] complex obeys Beer's law in 0.118–3.534 μg mL−1 range with a detection limit of 0.04 μg mL−1 and molar absorptivity, ɛ of 2.3 × 104 L mol−1 cm−1. Highly sensitive and selective first-, second- and third-order derivative methods are described for the determination of iron and cobalt. A simultaneous second-order derivative spectrophotometric method is proposed for the determination of these metals. All the proposed methods are successfully employed in the analysis of various biological, water, and alloy samples for the determination of iron and cobalt content.

Fundamentals and Applications of Analytical Chemistry in Natural Products

This special issue is aimed at collecting together recent developments in the field of natural product analysis. This issue covers methodologies and applications as diverse as secondary metabolite identification to the detection of metals in food stuffs. The chemistry of natural products has gained prominence not only due to the on-going search for new bioactive substances but also in related areas such as food chemistry and chemical ecology. We feel that this special issue represents some of the wide ranging research currently performed in this diverse area and this is exemplified by the affiliations of the authors of the papers included which is made up of chemists, biochemists, biologists, physicists, toxicologists, physiologists, pharmaceutists, and geochemists. What all of these researchers have in common, despite their wide ranging backgrounds, is the need to make use of the powerful techniques of analytical chemistry to analyze natural compounds in complex matrices. Thus, this special issue is dedicated to all the readers that would like to apply analytical chemistry for natural products analysis. This issue presents ten papers, which describe either a specific analytical method for specific types of natural products, the use of natural compounds to aid analytical developments, or modern techniques for the analysis of metals in food stuffs and food quality control (a growing area of interest). The article by L. de S. Ferreira et al. describes the use of hyphenated techniques to determine fatty acids in a species of seaweed from the Fernando de Noronha archipelago. In addition, a second paper has used SRTXRF analysis as a technique to determine several inorganic species within the same archipelago. Both papers contribute to an increased understanding of adsorption and accumulation of such natural elements by algae in that specific area. V. S. A. Devi and V. K. Reddy's paper presents a methodology for spectrophotometric determination of iron(II) and cobalt(II) using 2-hydroxi-1-naphthaldehyde-p-hydroxybenzoichydrazone which can then be applied for the analyses of biological and water samples that contain these metals. The paper by G. C. Lopes et al. reports the preliminary estimation of the stability of the dried extract from the bark of Guazuma ulmifolia Lam. (“Mutamba”). Thermogravimetry analysis along with HPLC were used in the study. The results can be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The study by M. F. Zampa et al. is the first report of the antimicrobial peptide from the skin of the Phyllomedusa hypochondrialis frog and its incorporation into nanostructured layered films in conjunction with nickel-tetrasulfonated phthalocyanines. The film was used as a biosensor to detect dopamine, a neurotransmitter associated with diseases such as Alzheimer's and Parkinson's. S. B. A. Barros et al. demonstrate the exploitation of the polyelectrolytic behavior of natural cashew gum (Anacardium occidentale L.), found in northeast Brazil, as a component of a nanocomposite electrode. The performance of the electrodes was evaluated by the determination of dopamine. The paper by H. Tanaka et al. presents matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the confirmation of the hapten number in synthesized antigens. Two unique applications using MAb, Eastern blotting, and knockout extract have been introduced in this paper. The Eastern blotting method has great potential applications for the wide range of natural products. The article of S. R. de Moraes et al. highlights the use of Lippia sidoides Cham. (also known as alecrim pimenta), native to northeastern Brazil and northern Minas Gerais, and their essential oils. The oxygenated monoterpene 1,8-cineole was the major constituent, followed by isoborneol and bornyl acetate. The chemical composition of essential oils described in this paper differs from that described in the literature for L. sidoides found in its native environment. The paper of M. J. Kato et al. demonstrates the GC-MS monitoring of the major secondary metabolites and fatty acids occurring in the seeds of Virola surinamensis, during germination and seedling development. The authors conclude that the germination of V. surinamensis seeds and the seedling development are processes in which both fatty acids and secondary metabolites (lignans, isoflavonoids and juruenolides) are equally consumed in the seeds indicating their potential physiological role as energy and carbon sources. The article of P. J. Gates and N. P. Lopes describes the application of negative ion chip-based nanospray tandem mass spectrometry for the analysis of flavonoid aglycones. The methodology is tested by the analysis of a crude green tea extract, where the expected flavonoids were readily identified. Norberto P. Lopes Ernani Pinto Michael Niehues Paul J. Gates Ricardo Vessecchi