Spectrophotometric Determination Of Total Iron Research Articles

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

A Friendly Complexing Agent for Spectrophotometric Determination of Total Iron.

Iron, one of the most common metals in the environment, plays a fundamental role in many biological as well as biogeochemical processes, which determine its availability in different oxidation states. Its relevance in environmental and industrial chemistry, human physiology, and many other fields has made it necessary to develop and optimize analysis techniques for accurate determination. Spectrophotometric methods are the most frequently applied in the analytical determination of iron in real samples. Taking advantage of the fact that desferrioxamine B, a trihydroxamic acid used since the 1970s in chelation therapy for iron overload treatment, forms a single stable 1:1 complex with iron in whichever oxidation state it can be found, a smart spectrophotometric method for the analytical determination of iron concentration was developed. In particular, the full compliance with the Lambert-Beer law, the range of iron concentration, the influence of pH, and the interference of other metal ions have been taken into account. The proposed method was validated in terms of LoD, LoQ, linearity, precision, and trueness, and has been applied for total iron determination in natural water certified material and in biological reference materials such as control human urine and control serum.

Automated Spectrophotometric Multi-Pumping Flow System for the Determination of Total Iron in Wine

A new automated system based on a multi-pumping flow system (MPFS) for the spectrophotometric determination of total iron in various wine samples is presented. This analytical protocol is based on the complex formation between Fe (II) and 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP). The addition of ascorbic acid allows the determination of total iron by reducing the Fe (III) present in the samples to Fe (II). Several physical and chemical parameters, including the mixing coil length, the sample volume, the chromogenic reagent concentration, the pH, and the ascorbic acid concentration have been characterized in order to optimize the analytical conditions. The limits of detection and quantification were 34 µg L−1 and 114 µg L−1 respectively. The developed procedure requires minimal sample preparation.

Multisyringe flow injection analysis (MSFIA) for the automatic determination of total iron in wines.

This work presents a multisyringe flow injection analysis (MSFIA) system for the automatic spectrophotometric determination of total iron in wine. The reaction is based on the complexation of Fe(II) with 2-(5-bromo-2-pyridylazo)-5-(diethylamino)-phenol (Br-PADAP). Ascorbic acid was used as reducing reagent for Fe(III) to Fe(II) and, in this way, to determine the total iron content in wine. The absorbance of the Fe(II)-(Br-PADAP)2 complex was measured at 748 nm. The proposed method provided a working rage from 0.36 to 5 mg L-1 of Fe(II), with a detection limit of 0.11 mg L-1 of Fe(II), a relative standard deviation of 0.42% (3 mg L-1 of Fe(II), n = 10), and a 46 h-1 injection throughput. The system is very simple, rapid and selective, and has been successfully applied to determine total iron in red, rosé and white wine without any need for sample pre-treatment steps. The results agree well with ICP-AES, which used as a reference method.

Spectrophotometric Determination of Total Iron in Rice and Maize Samples

Scientific World, Vol. 11, No. 11, July 2013, page 101-104 DOI: http://dx.doi.org/10.3126/sw.v11i11.8562

Improved Spectrophotometric Determination of Total Iron and Iron(III) with <i>o</i>-Hydroxyhydroquinonephthalein and Their Characterization

Simultaneous and fractional determination of iron(II) and iron(III) was accomplished with o-hydroxyhydroquinonephthalein (QP) in the presence of poly (N-vinyl pyrrolidone). In the determination of total iron (iron(II)+iron(III)), Beer's law was obeyed in the range of 0.02-0.67 μg·ml(-1), with an effective molar absorptivity (at 570 nm) and a relative standard deviation of 1.30×10(5)·l·mol(-1)·cm(-1) and 0.77% (n = 8), respectively. This method was about 10-15 times and more than the methods using 1,10-phenanthroline and 2,2'-bipyridine. In addition, the iron-QP complex was characterized using spectrophotometry and the electron spin resonance. This method was successfully applied to assays of total iron and iron(III) in pharmaceutical preparations.

Kinetic Spectrophotometric Determination of Total Iron in Natural Water by Flow Injection Analysis Using On-Line Preconcentration

A new flow injection catalytic spectrophotometric method for on-line preconcentration and determination of total iron in natural water is described. The method is based on a combination of iron-catalyzed oxidation of diaminoditolyl by potassium bromate and the use of on-line preconcentration of iron onto 8-hydroxy-quinoline immobilized on silica gel. The corresponding calibration graph is linear over the range of 2.0–110 ng mL−1 for Fe(III) using a time-based technique for 5 min preconcentration. The relative standard deviation of 11 measurements of 60 ng mL−1 Fe(III) was 0.67%. The method was applied to the determination of iron in natural water. The results obtained by the proposed method were compared with those obtained by ICP-AES. The t-test showed no significant differences between the two methods at a confidence level of 95%.

A flow system with in-line blank correction applied to the spectrophotometric determination of total iron and chromium (VI) in wastewaters.

A flow system using the sample as the carrier with a propulsion device located after the detector is presented. This approach allows the correction of the intrinsic color of the sample, as it provides baseline adjustment for each sample. A confluence situated just after the selection valve allows the sample composition to be adjusted for the colorimetric measurement. The developed methodology was applied to the colorimetric determination of total Fe and Cr (VI) in wastewaters at 0.1-6.0 mg L-1 and 0.03-1.0 mg L-1, respectively. RSDs lower than 3% and a sampling rate of approximately 40 h-1 were obtained.

Simultaneous Spectrophotometric Determination of Iron(II) and Iron(III) in Mixtures Using Di-2-pyridyl Ketone Benzoylhydrazone

Abstract A method for simultaneous spectrophotometric determination of total iron, iron(II) and iron(III) in mixtures containing other metal ions has been described. The method is based on the complexation of iron with di-2-pyridyl ketone benzoylhydrazone (DPKBH) in 50% (v/v) ethanolic solution. Iron(II) complex with DPKBH exhibits two absorption maxima at 360 and 650 nm. meanwhile iron(II1) complex with DPKBH exhibits only one maximum at 360nm. Iron(II) and iron(III) complexes with DPKBH have similar behaviour at 360nm. Iron forms 1:2 complexes with the reagent. Beer's laws are obeyed over the ranges 0.1–2 μgml-1 and 0.4–5 μgrn1-l for iron(II) complexes at 360 and 650nm respectively. Iron(III) showed results similar to those obtained for iron(II) at 360nm. The effect of pH, effect of excess reagent. the stability of complexes. and the tolerance limit of many metal ions have been reported. The method is applied to the determination of total iron, iron(I1). and iron(II1) in synthetic solutions.

Flow-injection analysis of silicate rocks for total iron and aluminium

A flow-injection method is described for the spectrophotometric determination of total iron and aluminium in silicate rocks. Rock samples are opened up by fusion with a mixture of lithium carbonate and boric acid, the melt is taken up in 1 M hydrochloric acid and the resulting solution is used for the determination of both iron and aluminium. The flow system for the determination of iron needs no particular reagents, involving simply measurement of the absorbance of the chloro-complex of iron(III) at 335 nm. The system for aluminium consists of the reduction of iron(III) to iron(II), colour development with Xylenol Orange (XO), destruction of XO-chelates other than that of aluminium by addition of EDTA and subsequent measurement of the absorbance of the aluminium—XO complex at 506 nm. The systems permit semi-automatic, rapid analysis of silicate rocks for iron and aluminium. Results obtained for standard rocks were in good agreement with the recommended values. The precision ranged from 0.1 to 0.9% for iron and from 0.3 to 0.7% for aluminium.

Precision spectrophotometric determination of total iron in chromite ores

Chemical and manipulative variables have been examined in detail in order to develop a precise and direct spectrophotometric determination of total iron in chromite ores. Samples are sintered with sodium peroxide in zirconium crucibles (3 h at 510 ± 10 °C), then leached and filtered. The filtrate can be used for the determination of chromium. The residue is dissolved in hydrochloric acid (1 + 1) and iron is determined from the absorbance of the iron(III)-chloro complex at 342 nm. The procedure has been evaluated using standard chrome-iron samples and a series of Sudanese chromite ores. The results are in good agreement and of comparable precision with other data.

Performance characteristics for the spectrophotometric determination of total iron in freshwater using hydrochloric acid

A method is described for the determination of total iron in freshwater using a wet-oxidation procedure followed by spectrophotometric measurement in 5.93 ± 0.07 M hydrochloric acid.It has been used successfully in routine analysis for several years and requires only standard equipment and inexpensive reagents. The criterion of detection is 0.009 mg l–1 for the 95% confidence level. The relative standard deviation at 0.2 mg l–1 is 4.4% and at 3 mg l–1 is 1.5% for 19 degrees of freedom. Comprehensive interference tests show that the method is adequately selective for use with freshwater. Copper is the only substance to interfere significantly and below 0.1 mg l–1 it has a negligible effect.