Determination Of Ferric Ions Research Articles

Determination of Ferrous Ion in Pure & Pharmaceutical Preparation by Continuous Flow Injection Analysis Via Turbidmetric Utilizing NAG-4SX3-3D Analyzer

Determination of Ferrous Ion in Pure & Pharmaceutical Preparation by Continuous Flow Injection Analysis Via Turbidmetric Utilizing NAG-4SX3-3D Analyzer

Hydrothermal Synthesis of Carbon Quantum Dots from Persimmons as Probe for Determination of Ferric Ions.

Local natural persimmons were used as a new precursor to synthesize carbon quantum dots (CQDs) by a brief and environment friendly strategy, hydrothermal method. The as-prepared CQDs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, Ultraviolet-visible spectroscopy, as well as fluorescence spectrophotometer. The average diameter of CQDs was 2.5±0.5 nm with spherical shape and exhibited blue fluorescence with the maximum emission wavelength at 438 nm and excitation wavelength at 345 nm. The influences of pH and ionic strength on CQDs fluorescence were evaluated. Moreover, the CQDs were used for determination of Fe3+ by blue fluorescence quenching as the result of the interaction between Fe3+ and -OH, -COOH on the CQDs surfaces. The proposed CQDs displayed high selectivity and sensitivity of Fe3+ in comparison with other metal ions. Therefore, a good linear relationship was established with the Fe3+ concentration in the range of 0.6-400 μM. The correlation coefficient of the calibration curve was 0.996. The detection limit of the method was 0.56 μM. Eventually, the CQDs made from persimmons were used for determination of Fe3+ in actual water sample with satisfactory results and gave recoveries between 95.66% and 99.90%. The relative standard deviation was 1.20%-1.86%. The results demonstrated the potential towards diverse applications of the local persimmons.

Determination of ferric ion via its effect on the enhancement of the chemiluminescece of the permanganate-sulfite system by nitrogen-doped graphene quantum dots.

Nitrogen-doped graphene quantum dots (NGQDs) are shown to strongly enhance the integrated chemiluminescence (CL) of the permanganate-sulfite system. The mechanism of enhancement was investigated, and the catalytic effect of the NGQDs was proven. In contrast to other carbon-based nanomaterials, the enhancement by NGQDs is independent of particle size and surface. However, the pyridinic nitrogen on the surface of the NGQDs facilitates the transformation of dissolved oxygen into H2O2 and the generation of hydroxyl radicals. This induces the increase of CL intensity. However, in the presence of Fe3+, the nitrogen functions and phenol groups on the surface of the NGQDs will chelate it, and the CL signal is decreased as a result. This effect was used to design an assay for Fe3+ that has a wide response range (1 × 10-8 - 1 × 10-6M) and a 4nM detection limit. The method was successfully applied to the determination of Fe3+ in spiked real water samples. Graphical abstract Nitrogen-doped graphene quantum dots (NGQDs) are demonstrated to strongly enhance the integrated chemiluminescence (CL) of the permanganate-sulfite system. The pyridinic N-atoms in NGQDs facilitate the transformation from dissolved oxygen into H2O2 and the generation of •OH radicals. This leads to the highly enhanced CL of the system. In the presence of Fe3+, which will be chelated by the nitrogen functions and phenol groups on the surface of the NGQDs, the CL signal is decreased.

Correction: Determination of ferric ions using surface-enhanced Raman scattering based on desferrioxamine-functionalized silver nanoparticles.

Correction for 'Determination of ferric ions using surface-enhanced Raman scattering based on desferrioxamine-functionalized silver nanoparticles' by Fei Yan et al., Chem. Commun., 2013, 49, 7962-7964.

A novel sensing membrane for the determination of ferric ions in aqueous solutions

A new sensing membrane is proposed for the determination of Fe3+ over other common metal ions in an aqueous solution based on the quenching of the fluorescence intensity of the membrane by Fe3+. The fluorescence intensity of the membrane showed distinct changes towards Fe3+ with fast response, satisfactory stability and excellent sensitivity.

Fluorescent sensors based on quinoline-containing styrylcyanine: determination of ferric ions, hydrogen peroxide, and glucose, pH-sensitive properties and bioimaging.

A novel styrylcyanine-based fluorescent probe 1 was designed and synthesized via facile methods. Ferric ions quenched the fluorescence of probe 1, whereas the addition of ferrous ions led to only small changes in the fluorescence signal. When hydrogen peroxide was introduced into the solution containing probe 1 and Fe(2+) , Fe(2+) was oxidized to Fe(3+), resulting in the quenching of the fluorescence. The probe 1/Fe(2+) solution fluorescence could also be quenched by H2 O2 released from glucose oxidation by glucose oxidase (GOD), which means that probe 1/Fe(2+) platform could be used to detect glucose. Probe 1 is fluorescent in basic and neutral media but almost non-fluorescent in strong acidic environments. Such behaviour enables it to work as a fluorescent pH sensor in both the solution and solid states and as a chemosensor for detecting volatile organic compounds with high acidity and basicity. Subsequently, the fluorescence microscopic images of probe 1 in live cells and in zebrafish were achieved successfully, suggesting that the probe has good cell membrane permeability and a potential application for imaging in living cells and living organisms.

Determination of ferric ions using surface-enhanced Raman scattering based on desferrioxamine-functionalized silver nanoparticles

A simple, robust and reproducible spectroscopic method based on surface-enhanced Raman scattering with nanomolar sensitivity has been developed for selective iron(III) determination in aqueous solutions.

Determination of iron by catalytic oxidation of p-aminophenol by hydrogen peroxide

The oxidation reaction of p-aminophenol by hydrogen peroxide was studied in the presence of ferric ions, which catalyzes it. The corresponding rate constants were calculated and the activation energy was determined. A method for ultramicrodetermination of ferric ion was developed using the method of tangents. Determination of ferric ions from 0.5 × 10 −1 up to 4.5 × 10 −2 μg/ml is possible with a relative mean error of ± 1.55%. The influence of several ions was also investigated.

Spectrophotometric study of complexation equilibria and of a method for the determination of Fe(III) ions with 4-(2-pyridylazo)resorcinol and 4-(2-thiazolylazo)resorcinol

The composition, molar absorption, coefficients, equilibrium constants and stability constants for the MLH, ML, M(LH)2 and ML2 complexes have been determined graphically using slope-intercept transformations and numerically from the absorbance-pH curves and from the absorbance dependence on the component concentration, using the PRCEK III and SPEKTFOT programs, or from the continuous variation plots using the JOBCON program. The optimum conditions were found for a spectrophotometric determination of ferric ions with TAR and PAR reagents in pure solutions. The basic parameters of the analytical curves were evaluated using the STAT program.

Determination of ferrous ion in microsamples of hexagonal ferrites

A sensitive and accurate method is described for determining microgram amounts of ferrous iron associated with a large excess of ferric iron and various bivalent cations, in hexagonal ferrites. Ferrous iron is complexed with bathophenanthroline, extracted into a chloroform-ethanol mixture and spectrophotometrically measured at 540 nm against a 1∶3 v/v chloroform-ethanol mixture. Ferric iron is masked with ammonium dihydrogen phosphate. The analytical conditions are stated for determination of iron(II) in both solvents used for ferrites, viz., hydrochloric and phosphoric acids. Cobalt, copper, and nickel do not interfere if the procedures suggested are used. Ferrous iron down to 0.02% can be determined in samples weighing only a few milligrams.

(294)第一水銀塩を還元剤として用いる容量法-第二鉄および第二銅イオンの定量-

(294)第一水銀塩を還元剤として用いる容量法-第二鉄および第二銅イオンの定量-

α-Picolinic acid as a colorimetric reagent: Determination of ferrous ion

α-Picolinic acid has been used as a reagent for the colorimetric estimation of ferrous ion. The transmittancy measurements show that iron from 0.08 p.p.m. to 12 p.p.m. may be easily determined with a cell of capacity 16 ml and thickness 20 mm. The effect of time, temperature and of diverse ions on the coloured system with an absorption maximum at 440 mμ have been critically examined. The optimum range with minimum relative error is found to be in the region of 1.6 to 8 p.p.m. By job's method the composition of the ferrous complex, which is highly soluble and stable in water, is Fe(C 6H 4O 2N) 2 with a dissociation constant in the order of 10 -5. α-Picolinsäure wurde als Reagens zur kolorimetrischen Bestimmung von Ferroionen benutzt. Mit dieser Methode kann man leicht Eisen in einer Konzentration von 0.08-12‰ in einer Zelle mit einem Fassungsvermögen von 16 ml und einer Dicke von 20 mm bestimmen. Der Einfluss der Zeit, der Temperatur und verschiedener anderer Ionen auf das gefärbte System mit einem Absorptionsmaximum bei 440 mμ wurde kritisch überprüft. Der optimale Bereich mit dem geringsten relativen Fehler wurde in dem Gebiet von 1.6-8‰ gefunden. Die Zusammensetzung des Ferrokomplcxes, der ausserordentlich gut löslich und stabil in Wasser ist, ist nach der Job'schen Methode Fe(C 6H 40 2N) 2 und besitzt eine Dissoziationskonstante in der Grössenordnung von 10 -5.