Quantitative Determination Of Iron Research Articles

MRI for Quantitative Determination of Iron in the Liver and Heart in Patients with Primary and Secondary Hemochromatoses in Association with Serrum Ferritin: Single-Stage Observational Study

Background. An extremely small number of studies have been devoted to the study of differences in LIC (liver iron concentration) and MIC (myocardium iron concentration) indicators, as well as their correlation with each other and with ferritin levels in patients with various nosological forms. Aims to study the relationship of ferritin, LIC and MIC levels in patients with various causes of hemochromatosis (hereditary hemochromatosis (HH), aplastic anemia (AA), primary myelofibrosis (PMF), thalassemia (TL), myelodysplastic syndrome (MDS)). Methods. The design of the study is a singlestage observational one. The study included 91 patients with primary hemochromatosis and secondary transfusion-dependent hemochromatosis receiving regular blood transfusion and iron chelate therapy from 2015 to 2018. The studies were carried out on 1.5 T MR-scanner Magnetom Espree (Siemens, Germany), and myocardial iron concentration (MIC) was calculated using the formula MIC = 45 (T2*) 1.22. Liver iron concentration (LIC) was calculated using the formula LIC = 0.03 R2* + 0.74. The ferritin level was determined by enzyme immunoassay. Statistical processing of the results obtained was carried out using the SPSS software package. Results. Connections between LIC and ferritin (r = 0.867; p 0.001), MIC and ferritin (r = 0.759; p = 0.004) and LIC and MIC (r = 0.737; p = 0.006) were found in patients with primary hemochromatosis, while in patients with secondary hemochromatosis significant correlations were found only between LIC and MIC (r = 0.503; p 0.001), while the relationship was average. Links between LIC and ferritin were found in patients with AA (r = 0.656; p = 0.040), an average relationship, in patients with TL (r = 0.714; p = 0.020), an average relationship. The relationship between MIC and ferritin was revealed in patients with AA (r = 0.703; p = 0.050), an average relationship, in patients with TL (r = 0.757; p = 0.018), an average relationship. At the same time, in patients with MDS and PMF in this study, there was no association between ferritin and LIC, ferritin and MIC. Conclusions. In patients with hereditary hemochromatosis, LIC and MIC are associated with ferritin, and MIC is also associated with LIC (medium bond). In patients with iron overload due to thalassemia, an average correlation between LIC and ferritin, MIC and ferritin was revealed. In patients with iron overload due to aplastic anemia, an average correlation between LIC and ferritin, MIC and ferritin was revealed.

Quantitative determination of iron citrate/malate complexes by isotope–dilution hydrophilic interaction liquid chromatography – electrospray MS/inductively coupled plasma MS

Quantitative speciation of low molecular weight iron complexes based on the in situ generation of isotopically-labelled species reflecting the natural iron speciation in coconut water as a model endosperm liquid.

A novel “turn-off” fluorescent sensor based on cranberry derived carbon dots to detect iron (III) and hypochlorite ions

A novel fluorescent carbon dots (CDs) have been prepared for the quantitative determination of iron(III) (Fe3+) and hypochlorite (ClO−) ions separately. Firstly, CDs were successfully synthesized using a hydrothermal treatment which is a green and simple method from cranberry as a novel natural resource. They were precisely characterized using advanced instruments. Secondly, CDs were separately studied by absorption and fluorescence spectroscopy as a fluorescence sensor for various metal cations and anions, respectively. As a result of spectroscopic data, it was showed that CDs were effectively quenched with Fe3+ ions among various cations and ClO− ions among various anions, respectively. The fluorescence intensities of CDs were quenched by forming a non-radiative complex between Fe3+ and CDs, and LOD for Fe3+ was calculated as 0.75 nM in the range of 1.6 nM to 22.8 nM. Furthermore, their fluorescence intensities are quenched by oxidizing of the hydroxyl groups on surface of CDs with ClO− ions, which have strong oxidant properties, and a detection limit (LOD) for ClO− was calculated as 1.60 nM in the range of 9.9 nM to 78.0 nM. Also, the proposed method to detect Fe3+ and ClO− ions was successfully applied in real natural spring and tap water samples. All data showed that these novel CDs could be used as a highly selective and sensitive, and instantaneously responsive “turn-off” fluorescence sensor for Fe3+ and ClO− ions.

Spectrophotometric Estimation of Iron (III) in Iron Polysaccharide Complex Capsule Formulation and its Accelerated Stability

Iron plays a pivotal role in human physiology, while its deficiency may prove fatal in severe cases. Analytical methods for the quantitative determination of iron are thus very important. Herein, we report the estimation of iron in iron Polysaccharide complex (IPSC) using raw material and formulations, through a spectrophotometric analytical method. IPSC capsules were formulated and their stability was studied by developing a simple and validated analytical method. The process is based on the acid hydrolysis of IPSC and the development of chromogen by reacting ammonium thiocyanate with IPSC, maximum absorption at 474 nm was observed. Beerand#39;s Lambert law (linearity response) was found in the range of 10-20 μg/ml with excellent correlation coefficient of determination (R = 0.998). The quantification and detection limits were established to be 0.45 mcg/ml and 0.14 mcg/ml correspondingly. The recovery of IPSC analysis was 99.25 to 102.28 %. Percentage assay of IPSC capsules showed results around 102.34 %. The formulated IPSC capsule was stable under accelerated conditions for 6 months (% assay andgt; 91.69). The dissolution profile over 60 minutes showed a better dissolution (94%) compared with the internationally marketed IPSC capsule (92%).

Spectrophotometric Estimation of Iron (III) in Iron Polysaccharide Complex Capsule Formulation and its Accelerated Stability

Iron plays a pivotal role in human physiology, while its deficiency may prove fatal in severe cases. Analytical methods for the quantitative determination of iron are thus very important. Herein, we report the estimation of iron in iron Polysaccharide complex (IPSC) using raw material and formulations, through a spectrophotometric analytical method. IPSC capsules were formulated and their stability was studied by developing a simple and validated analytical method. The process is based on the acid hydrolysis of IPSC and the development of chromogen by reacting ammonium thiocyanate with IPSC, maximum absorption at 474 nm was observed. Beerand#39;s Lambert law (linearity response) was found in the range of 10-20 μg/ml with excellent correlation coefficient of determination (R = 0.998). The quantification and detection limits were established to be 0.45 mcg/ml and 0.14 mcg/ml correspondingly. The recovery of IPSC analysis was 99.25 to 102.28 %. Percentage assay of IPSC capsules showed results around 102.34 %. The formulated IPSC capsule was stable under accelerated conditions for 6 months (% assay andgt; 91.69). The dissolution profile over 60 minutes showed a better dissolution (94%) compared with the internationally marketed IPSC capsule (92%).

X-ray fluorescence determination of ore elements in ferromanganese formations

Elemental analysis of ferromanganese formations (first, determination of the ore elements) is a necessary stage in the development of ore deposits. A technique for X-ray fluorescence quantitative determination of iron, manganese, cobalt, nickel, copper and zinc in oceanic ferromanganese formations (nodules and crusts) is proposed. The study was performed on wavelength-dispersive spectrometer S4 Pioneer (Bruker AXS, Germany) with LiF (200) crystal and scintillation detector. To plot the calibration curves, sets of certified reference materials of ferromanganese nodules, cobalt-bearing ferromanganese crusts and pelagic sediments, previously dried for 24 hours at 105°C to remove hygroscopic moisture were used. Two sample preparation techniques were compared: pressing of powder samples on a boric acid substrate and homogenization by fusion with lithium tetraborate in a ratio of 1 : 30 in an electric furnace at 1050 °C. For each sample preparation technique spectral overlaps and matrix correction methods (theoretical and empirical) were considered and optimal calibration curves for determination of ore elements were selected. The accuracy of the X-ray fluorescence technique was assessed in analysis of a certified reference material FeMn-1 and reference ferromanganese nodule sample using atomic absorption spectrometry on an M403 spectrometer (PerkinElmer, USA). Both homogenization by fusion and analysis of pressed samples provide quantitative X-ray fluorescence determination of the main ore elements and can be used to assess the industrial significance of oceanic ferromanganese formations.

The anti-corrosion behaviour of Satureja montana L. extract on iron in NaCl solution

AbstractThe effect ofSatureja montana L. extract (SM) and phenolic fraction ofSatureja montanaL. (PF) on the corrosion behaviour of iron in 0.1 mol L-1sodium chloride solution was studied by electrochemical techniques, UV/Vis spectrophotometry and atomic absorption spectrometry. The results of all techniques showed that SM and PF contributed to iron corrosion inhibition. The calculated inhibition efficiency values were about 45% for SM and 55% for PF. Results indicate that the inhibitive action occurs via a precipitation of the Fe-complex onto the iron surface which resulting in a decrease of the passive current density. The atomic absorption spectrometry (AAS) method was applied to the quantitative determination of iron in solution. The obtained results demonstrated good agreement with results obtained by electrochemical techniques.

Comparison of EPR Fe3+-Transferrin Versus Approved Clinical Chemistry Test for Serum Iron Measurements in Professional Ice Hockey Players and Nonathletic Controls

This study aimed to evaluate occult abnormalities of iron turnover in elite professional athletes. Electron paramagnetic resonance (EPR) and in vitro test for the quantitative determination of iron in human serum on “Cobas Integra 400 Plus” (CI) Roche automatic analyzer were used to evaluate the iron turnover in professional ice hockey players from four teams of the Continental Hockey League (study group, n = 110) and in two different control groups. The first group consisted of nonathletic young men (healthy controls, n = 25). The second group included male and female patients with different pathological conditions (comparison group, n = 16). The data pairs were compared using linear regression analysis, EPR data versus CI measurements. In the control and the comparison groups, EPR Fe3+ data associated with transferrin were highly correlated with CI serum iron measurements (squared correlation coefficient, r2 = 0.95). In the study group, correlation of the EPR Fe3+ measurements with CI serum iron levels in different teams of ice hockey players was statistically less powerful (r2 ranged from 0.61 to 0.78). Acute-phase copper-containing protein ceruloplasmin serum levels determined by EPR are also reported. Acute-phase responses were undetectable in most hockey players within quarterly scheduled medical examinations. The EPR spectroscopy combined with the routine biochemical serum iron measurements enable to detect occult dysmetabolic changes in iron turnover during intensive physical exercises. The results obtained support the use of EPR spectroscopy in the sports medicine because it helps to avoid misinterpretation of personalized biochemical markers and could facilitate the proper monitoring of iron-targeted interventions.

Method for increasing the accuracy of quantitative determination of iron by LIBS

Method for increasing the accuracy of quantitative determination of iron by LIBS

A spectral X-ray CT simulation study for quantitative determination of iron

Iron is an essential element in the human body and disorders in iron such as iron deficiency or overload can cause serious diseases. This paper aims to explore the ability of spectral X-ray CT to quantitatively separate iron from calcium and potassium and to investigate the influence of different acquisition parameters on material decomposition performance. We simulated spectral X-ray CT imaging of a PMMA phantom filled with iron, calcium, and potassium solutions at various concentrations (15–200 mg/cc). Different acquisition parameters were considered, such as the number of energy bins (6, 10, 15, 20, 30, 60) and exposure factor per projection (0.025, 0.1, 1, 10, 100 mA s). Based on the simulation data, we investigated the performance of two regularized material decomposition approaches: projection domain method and image domain method. It was found that the former method discriminated iron from calcium, potassium and water in all cases and tended to benefit from lower number of energy bins for lower exposure factor acquisition. The latter method succeeded in iron determination only when the number of energy bins equals 60, and in this case, the contrast-to-noise ratios of the decomposed iron images are higher than those obtained using the projection domain method. The results demonstrate that both methods are able to discriminate and quantify iron from calcium, potassium and water under certain conditions. Their performances vary with the acquisition parameters of spectral CT. One can use one method or the other to benefit better performance according to the data available.

Quantitative Determination of Iron in Limonite Using Spectroscopic Methods with Senior and General Chemistry Students: Geology-Inspired Chemistry Lab Explorations

Limonite is the field term for a mixed assemblage of ferric oxyhydroxides, often containing nonferric silicate impurities. It is abundant on Earth’s surface, possesses variable iron content, and is easily recognized by distinctive yellow and ochre hues. Limonite is a unique centerpiece for undergraduate chemistry laboratories because each sample represents a true unknown to faculty and students alike, and because limonite does not digest readily with common methods. Senior students were guided through a primary literature review to assess and establish an appropriate digestion method. Students then constructed the procedure for determining the iron content in limonite using atomic absorption spectroscopy. A final report, produced in the style of this Journal, completed the start-to-finish process used by scientists, helping students learn how novel problems are solved in the laboratory. General chemistry students were provided with limonite extracts and used UV–vis spectroscopy to determine their iron con...

Pyruvate Formate-lyase and Its Activation by Pyruvate Formate-lyase Activating Enzyme

The activation of pyruvate formate-lyase (PFL) by pyruvate formate-lyase activating enzyme (PFL-AE) involves formation of a specific glycyl radical on PFL by the PFL-AE in a reaction requiring S-adenosylmethionine (AdoMet). Surface plasmon resonance experiments were performed under anaerobic conditions on the oxygen-sensitive PFL-AE to determine the kinetics and equilibrium constant for its interaction with PFL. These experiments show that the interaction is very slow and rate-limited by large conformational changes. A novel AdoMet binding assay was used to accurately determine the equilibrium constants for AdoMet binding to PFL-AE alone and in complex with PFL. The PFL-AE bound AdoMet with the same affinity (∼6 μM) regardless of the presence or absence of PFL. Activation of PFL in the presence of its substrate pyruvate or the analog oxamate resulted in stoichiometric conversion of the [4Fe-4S](1+) cluster to the glycyl radical on PFL; however, 3.7-fold less activation was achieved in the absence of these small molecules, demonstrating that pyruvate or oxamate are required for optimal activation. Finally, in vivo concentrations of the entire PFL system were calculated to estimate the amount of bound protein in the cell. PFL, PFL-AE, and AdoMet are essentially fully bound in vivo, whereas electron donor proteins are partially bound.

Spatially resolved (semi)quantitative determination of iron (Fe) in plants by means of synchrotron micro X-ray fluorescence

Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron μ-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials. In this paper, for the first time the distribution of Fe within tomato roots has been imaged and quantified by means of confocal μ-XRF and exploiting a recently developed fundamental parameter-based algorithm. With this approach, Fe concentrations ranging from few hundreds of ppb to several hundreds of ppm can be determined at the microscopic level without cutting sections. Furthermore, Fe (semi)quantitative distribution maps were obtained for the first time by using two opposing detectors to collect simultaneously the XRF radiation emerging from both sides of an intact cucumber leaf.

Recovery of Hg(0) from the Aqueous Hg(I/II) Present in Analyte Solution after Quantitative Determination of Iron

An easy and feasible approach to recover HgCl2, used in quantitative determination of iron values, as Hg(0) was described. Both Hg(I) and Hg(II), present in the solution after quantitative determination of iron, was completely reduced to Hg(0) by the addition of aluminium chips in more slightly excess than the stoichiometric amount. The purity of recovered Hg(0) was verified by comparing the value of density with pure mercury. This simple method may be useful to remove the mercury from other waste aqueous solutions before their discharge into the environment.

Detailed Carrier Lifetime Analysis of Iron-Contaminated Boron-Doped Silicon by Comparison of Simulation and Measurement

In this work, an extensive injection-level-dependent carrier lifetime study on intentionally iron-contaminated boron-doped silicon has been performed by using the Elymat carrier lifetime method. The influence of both iron and boron concentrations is investigated. Results from both Elymat measurement modes are considered and critically compared to simulations and deep level transient spectroscopy measurements. The results clearly indicate that for low injection conditions, surface passivation with diluted hydrofluoric acid is not sufficient, whereas so-called electrostatic passivation allows for correct lifetime measurements. Results from both Elymat measurement modes are modeled consistently. The results prove that using optimized measurement and evaluation procedures, the Elymat method is an appropriate technique for the quantitative determination of iron in case of iron being the relevant contaminant in boron-doped silicon.

Detailed Photocurrent Analysis of Iron Contaminated Boron Doped Silicon by Comparison of Simulation and Measurement

In this work, an extensive injection level dependent carrier lifetime study on intentionally iron contaminated boron-doped silicon has been performed by using the Elymat carrier lifetime method. The influence of both, iron and boron concentrations is investigated. Results from both Elymat measurement modes are considered and critically compared with simulations. The results clearly indicate that for low injection conditions, surface passivation with diluted HF is not sufficient whereas so-called electrostatic passivation allows for correct lifetime measurements. For the first time, results from both Elymat measurement modes are modeled consistently. The results prove that using optimized measurement and evaluation procedures the Elymat method is an appropriate technique for the quantitative determination of iron in case of iron being the relevant contaminant in boron doped silicon.

Thin-Layer Chromatography of Aluminium: Quantitative Densitometric Determination of Fe2+, Ni2+, Cu2+, and Si4+

Thin-layer chromatography in combination with scanning densitometry is used as a tool for the quantitative determination of some impurity and additive elements in aluminium. Microgram levels of iron, silicon, copper, nickel, titanium, magnesium, manganese, and zinc present in a high concentration aluminium matrix is detected, and selective separations of some of these elements are achieved on silica gel H layers developed with a mobile phase containing aqueous sodium chloride solution. The quantitative determination of iron, silicon, nickel, and copper are obtained from the densitometric evaluation of chromatograms and are compared with the respective optical emission spectral analytical data.

Twice-Daily Deferasirox Improves Cardiac Iron Chelation in the Gerbil Model of Iron Cardiomyopathy.

Introduction: Iron cardiomyopathy remains the leading cause of death in thalassemia major patients because effective chelation of cardiac iron is difficult. Cardiac iron stores respond more slowly to chelation therapy and appear to require a sustained gradient of labile iron species between myocytes and serum. We have previously demonstrated the efficacy of once-daily deferasirox in removing stored cardiac iron in the gerbil but changes in cardiac iron were relatively modest compared with hepatic iron. We postulated that twice daily dosing (BID), by sustaining a longer labile iron gradient from myocytes to serum, would produce better cardiac iron chelation than a comparable once daily dose (QD).Methods: Twenty four eight-to-ten week old female Mongolian gerbils underwent iron dextran loading for 10 weeks, followed by a 1 week iron equilibration period. Animals were divided into 3 treatment groups of 8 animals apiece and treated with deferasirox 100 mg/kg/day as a single dose (n=8), deferasirox 100 mg/kg/day divided BID (n=8), or sham chelation (n=8) for a total of 12 weeks. Following euthanasia, organs were harvested for quantitative iron determination and tissue histology.Results: All of the animals tolerated the 10-week loading and 12-week chelation with no adverse events. After the 22-week period, hepatic iron content was 17.7 ± 4.8 mg and 21.1 ± 5.3 mg in the QD and BID groups, compared with 43.1 ± 5.3 mg in the sham-chelated animals (p < 0.0001 sham versus treatment, p=0.2 between groups). Corresponding cardiac iron content was 0.19 ± 0.04 mg, 0.16 ± 0.04 mg and 0.23 ± 0.04 mg respectively. These changes were significant in the BID group (p< 0.006 versus sham). While BID versus QD cardiac iron contents were not statistically different, treatment groups were clearly distinct when viewed as a scattergram of heart and liver iron content (Figure 1). The BID treated animals exhibited lower cardiac iron for any given hepatic iron content. This is best observed by comparing the ratio of cardiac to hepatic iron content (Figure 2, which was 0.78% in the BID group versus 1.11% in the QD treated animals (p=0.0007).Discussion: In Mongolian gerbils, deferasirox effectively removed liver and cardiac iron with either BID or QD dosing. BID dosing changed the relative cardiac and liver iron chelation profile compared with QD dosing, trading improvements in cardiac iron elimination for a modest decrease in hepatic chelation. Caution should be exercised in extrapolating these results to humans, however clinical studies of BID administration should be considered for patients requiring high chelator dosing or who have high cardiac iron burden. [Display omitted] [Display omitted]

SIMULTANEOUS DETERMINATION OF IRON AND COPPER BY THIRD-DERIVATIVE SOLID-PHASE SPECTROPHOTOMETRY

ABSTRACT A simultaneous microdetermination of iron and copper at sub-µg/L level by solid phase derivative spectrophotometry has been developed. The compounds TPTZ (2,4,6-tripyridyl-1,3,5-triazine) and Neocuproine (2,9-dimethyl-1,10-phenanthroline hydrochloride), were used as chromogenic reagents to form a blue iron complex and an orange copper complex, respectively (pH = 5.0), which are fixed and concentrated on a cation-exchange resin sephadex sp C-25. The influence of experimental variables on the retention of the complexes on the resin are discussed. The signals in derivative units were measured directly on the solid, packed in a 1 mm spectrophotometric cell. The characteristic amplitude of the signals at 622.0 and 477.0 nm in third-derivative spectra are useful for quantitative determination of iron (0.195–120 ng mL−1; RSD = 1.8%) and copper (0.451–300 ng mL−1; RSD 1.3%). The method was applied to the iron and copper determination in different types of water, respectively.

The hepatologist in the haematologists' camp.

The hepatologist in the haematologists' camp.