Μg Of Iron Research Articles

A Flow-Injection Method for the Determination of the Total Iron using 3,4-Dihydroxybenzaldehyde

A home-made design flow-injection system has been described in a previous work. This system has been applied in the present work for the determination of total iron using the reagent 3,4-dihydroxybenzaldehyde (3,4-DHBA). Optimization of all conditions were as follows: λmax 440 nm., pH of the carrier stream(C.S) 8.8 and its flow rate with the reagent 1.1 ml.min-1, reagent concentration 0.001M and the Manifold length was 60cm. Optimum, linear range of the calibration curve plotted by the method of Least Square with any one of the two equations Y=a+bX or Y=bX; including zero (the blank reading) as one of the standards, was between 0 - 8ppm. total Iron. The accuracy of the method was measured by calculating percentage recovery of 10 μg Iron (II+III) added to samples of Iron-Drugs after dissolution with 0.1 MHCl. The error did not exceed 5% with Coefficient of Variation between 2.5 - 3.3% Paired Comparison by t-test between two calibration curves showed no significant difference at 95% confidence limit.

Alveolar macrophages accumulate iron and ferritin after in vivo exposure to iron or tungsten dusts

Extracellular iron present in alveolar structures may contribute to oxidative lung injury induced by toxic mineral dusts by enhancing dust-induced generation of hydroxyl radicals. Alveolar macrophages (AMs) can sequester iron within ferritin and limit generation of hydroxyl radicals. In the current study we sought to assess whether AMs accumulate iron and ferritin after in vivo exposure to a dust with high iron content, to iron oxide, or to an inflammatory dust, calcium tungstate. We performed lung lavage 1, 7, 14, 28, 42, and 56 days after intracheal instillation of mineral dust in saline solution or instillation of saline solution alone and quantitated cell recovery and AM content of iron and ferritin. Instillation of iron oxide increased neutrophil recovery only on day 1 when compared with results in controls, whereas calcium tungstate increased neutrophil recovery through day 14. AMs recovered after instillation of iron oxide contained increased amounts of iron and ferritin, beginning on day 1 and progressing through day 56 after treatment (7.57 ± 0.38 μg iron per 10 6 AMs vs 1.54 ± 0.28 μg iron per 10 6 AMs for controls, p < 0.001; and 5908 ± 768 ng ferritin per 10 6 AMs vs 395 ± 20 ng ferritin per 10 6 AMs, p < 0.001). AMs recovered after calcium tungstate instillation also contained increased amounts of iron and ferritin beginning 14 days after treatment, with greatest content 42 days after treatment (4.85 ± 0.68 μg iron per 10 6 AMs, p < 0.001, and 2274 ± 736 ng ferritin per 10 6 AMs, p < 0.001). Tumor necrosis factor, which can enhance iron accumulation by macrophages, was spontaneously released by AMs recovered from tungsten-treated rats. These studies indicate that AMs accumulate iron and ferritin in response to both iron loading of the lungs with iron oxide exposure and lung inflammation induced by calcium tungstate exposure.

Preconcentration of 1-(2-pyridylazo)—2-naphthol—iron(III)-capriquat on a membrane filter, and third-derivative spectrophotometric determination of iron(III)

Iron(III) was preconcentrated by collection on an organic solvent—soluble membrane filter (nitrocellulose (NC)) of the iron(III)–1-(2-pyridylazo)—2-naphthol (PAN) complex in the presence of capriquat as an oily quaternary ammonium salt. Third-derivative spectrophotometry was used for measurement of the third-derivative distance (d 3 A/dλ 3) between λ 1 = 520 nm and λ 2 = 590 nm or λ 3 = 660 nm and λ 4 = 724 nm of the iron(III)—PAN—capriquat complex or PAN—capriquat in dimethylsulfoxide (DMSO) following preconcentration. The calibration curve was linear in the range of 1–10 μg iron(III)/5.0 ml DMSO solution. The proposed method was about five-fold more sensitive and more selective than using zero-order spectrophotometry.

Iron overload in children receiving prolonged parenteral nutrition

This study was carried out to evaluate the iron status of 30 children aged 1 to 18 years who had been receiving total parenteral nutrition (TPN) for an average of 43 months with iron intakes of 100 micrograms/kg per day. Iron status was assessed by assaying the serum iron and ferritin levels and the transferrin saturation coefficient as a function of iron intake. Liver biopsy specimens were taken from 13 children. Twelve children had serum ferritin levels greater than 300 ng/ml, and 8 had levels greater than 800 ng/ml. The serum ferritin level and the transferrin saturation coefficient were positively correlated (r = 0.81; p < 0.01). The serum ferritin level was positively correlated with TPN duration and with the total iron intake (r = 0.68; p < 0.01). Of the 13 liver biopsy specimens, six showed signs of iron deposition. We conclude that there is a risk of iron overload in children receiving 100 micrograms iron per kilogram of body weight per day by TPN, indicating that intake should be reduced.

Application of ternary complexes in pharmaceutical analysis

The formation of a ternary complex of iron(III) with isoniazid-2-hydroxybenzaldehyde hydrazone(INSH) in a cetyltrimethylammonium bromide(CTAB) micellar medium, leads to a simple, sensitive and accurate spectrophotometric microdetermination of the iron(III), either in pure aqueous solutions or, particularly, in various anti-anaemic formulations. The apparent molar absorptivity of this complex and Sandell's sensitivity at 386 nm were 2.08×104 lmol−1 cm−1 and 2.68 ngcm−2, respectively. The calibration graph which was traced according to the regression line equation, A=3.70×10−1 C+1.09×10−3 (r=1.0000; n=28), was rectilinear for 100 ppb to 3.0 ppm of iron(III). The accuracy and the precision of the method could be considered as very satisfactory, since the mean CV% was 0.202 in the range 0.5–3.0 μg of iron(III) per ml. The results obtained for iron(III) by the new method and by the o-phenanthroline method, were compared statistically by means of the Student t-test and the variance ratio F-test; no significant difference was found.

Contaminant Iron in Water and Soil Samples and in Vitro Availability Studies

The iron content from 24 well water samples in tropical southern Nigeria ranged from 0.05 to 3.1 μg per millitre. Iron extracted from soil samples in deionized water, 0.1 M NaOH, 0.1 N HCI, and 0.1 N HCl-ascorbic acid averaged 79. 7, 146.3, 809.8, and 1,268.1 μg of iron per 100 g of soil sample respecfively. Extraction of iron from the soil samples was significantly affected (p &lt; .05) by the addition of ascorbic acid. The dialysable iron in some meals containing contaminant iron from the samples compared favourably with a standard meal with ferric chloride. Dialysable iron was influenced significantly (p&lt;.05) by the components in the meals. Meat and ascorbic acid enhanced the dialysability of contaminant iron sources in both the semi-synthetic meals and some tropical food items. The contribution of these contaminant iron sources to the diet of Nigerians in relation to the high frequency of iron-deficiency anaemia is discussed.

Determination of humic acid and iron(III) by solid-state spectrophotometry to study their interactions

A simple and sensitive method for the determination of humic acid has been developed. The method is based on the adsorptive enrichment of humic acid using a finely divided anion-exchange resin, collection of the resin on a membrane filter by filtration as a circular thin-layer, and direct measurement of the absorbance of the resultant thin-layer of resin by densitometry at 470 nm. Up to 80 µg of humic acid in 100 ml of sample solution can be determined, the limit of detection being 1.3 µg. The effect of iron(III) is masked with ethylenediaminetetraacetic acid (EDTA). Iron(III) is also determined by densitometry at 600 nm after enrichment on the thin-layer of resin as a complex with ammonium pyrrolidine dithiocarbamate (ammonium pyrrolidin-1-yldithioformate)(APDC), the limit of detection being 0.06 µg of iron(III). In the presence of humic acid, the blank value is obtained by masking the iron(III) as the EDTA complex, and calculating the net absorbance due to the APDC complex. The methods have been used to investigate the effect of humic acid on the formation of filterable iron(III) species, which can pass through a 0.45 µm membrane filter. The possibility of characterizing humic acid based on the formation of a complex with iron(III) has been shown.

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.

Simple and rapid spectrophotometric determination of iron after preconcentration as its 1,10-phenanthroline complex on the natural polymer “chitin”

Preconcentration by collection of metal complexes on chitin has been applied to the spectrophotometric determination of iron in water. The iron is collected as its 1,10-phenanthroline (phen) complex on a column of chitin in the presence of tetraphenylborate as counter-ion. The iron(II)—phen complex retained on the chitin is eluted with an acetone—1 M acetic acid mixture (8:2 v/v), and the absorbance of the eluate is measured at 512 nm. Beer's law is obeyed over the concentration range 1.1–11.2 μg of iron in 10 ml of eluate. In the presence of EDTA as masking agent, Ca, Mg, Al, Mn, Zn, Cd and Pb do not interfere in concentrations up to 100 times that of iron(II) and Co, Ni and Cu do not interfere in concentrations up to 20 times that of iron(II). Common inorganic anions do not interfere in concentrations up to 10,000 times that of iron(II). The proposed method has been applied to determination of iron in tap water.

Spectrophotometric determination of iron after separation of its 9,10-phenanthrenequinone monoximate on microcrystalline naphthalene

A sensitive and selective spectrophotometric method has been developed for the determination of iron as Fe(II) or Fe(III) using 9,10-phenanthrenequinone monoxime (PQM) as the complexing agent. Fe(II) and Fe(III) react with PQM to form coloured water insoluble complexes which can be adsorbed on microcrystalline naphthalene in the pH ranges 3.7–6.2 and 2.0–8.4, respectively. The solid mass consisting of the metal complex and naphthalene is dissolved in DMF and the metal determined spectrophotometrically by measuring the absorbances Fe(II) at 745 nm and Fe(III) at 425 nm. Beer's law is obeyed over the concentration range 0.5–20.0 μg of iron(II) and 20–170.0 μg of Fe(III) in 10 ml of DMF solution. The molar absorptivities are 1.333 × 104 1 · mole−1 · cm−1 for Fe(II) and 2.428 × 1031· mole−1 · cm−1 for Fe(III). The precision of determination is better than 1%. The interference of various ions has been studied and the method has been employed for the determination of iron in various standard reference alloys, bears, wines, ferrous gluconate, human hair and environmental samples.

Iron, zinc and boron deficiency in papaya

Papaya ( Carica papaya L.) cultivar ‘Honeydew’ was grown in refined sand with complete nutrition and at deficient levels of iron (0.014 or 0.056 mg l −1), zinc (0.0065 or 0.013 mg l −1) or boron (0.0033 or 0.033 mg l −1). The symptoms of deficiencies of iron and boron appeared in young leaves, and those of zinc in middle leaves. The depression in growth was maximum in iron deficiency and least in zinc deficiency. The affected leaves from plants which were acutely deficient in iron, zinc or boron contained as little as 85 μg iron, 13 μg zinc and 6.7 μg boron g −1 dry matter, respectively, whereas comparable leaves from normal plants contained 140 μg iron, 22.4 μg zinc and 17.3 μg boron g −1 dry matter, respectively.

Determination of Iron in Drug Biochemical and Biological Samples as a Thiocyanato Mixed Ligand Complex with Hydroxyamidine

Abstract N-Hydroxy-N-o-tolyl-N′-phenylbenzamidine (HTPB) is presented as a new sensitive and highly selective reagent for determination of iron in drug, biochemical and biological samples in presence of thiocyanate. The red organge Fe(III)–HTPB–SCN mixed ligand complex is quantitatively extracted into benzene. The extraction of iron(III) as thiocyanato mixed ligand complex is quantitative in the acidity range between 0.2–0.7 M (1M=1 mol dm−3) hydrochloric acid. The effective molar absorptivity of the complex is 12000 l mol−1 cm−1 with Sandell’s sensitivity of 0.0046 μg of iron per cm2. On the basis of this sensitive color reaction, a simple, rapid, selective, and highly reproducible method for the extractive spectrophotometric determination of microgram amounts of iron in various drug, biochemical and biological samples has been developed. The method is free from most of the common metal ions and commonly used sequestering agents.

Interactions among vanadium, iron, and cystine in rats growth, blood parameters, and organ Wt/body Wt ratios

In three fully crossed, three-way, two-by-two-by-four experiments, male weanling Long-Evans rats were fed a basal diet supplemented with vanadium (ammonium metavanadate)-at 0 and 1 μg/g, cystine at 3.0 and 8.5 mg/g, and iron (ferric sulfate) at 0 (Expts. 1 and 2) or 5 (Expt. 3), 15, 100, and 500 μg/g. After 6 wk, a relationship between vanadium and iron that was influenced by dietary cystine was found. The interaction among vanadium, iron, and cystine was demonstrated best by the hematocrit and hemoglobin findings, which were similar. In all Expts., hematocrits were depressed in rats fed the two lower levels of iron. In Expts. 2 and 3, vanadium deprivation exacerbated the depression of hematocrits in rats fed 15 μg iron and 3.0 mg cystine/g diet. In Expt. 1, the effect was similar, but less marked. On the other hand, in Expts. 1 and 3 when supplemental cystine was 8.5 mg/g, vanadium deprivation did not exacerbate, but tended to alleviate the depression of hematocrits in rats fed 15 μg iron/g diet. When dietary iron was 15 μg/g in Expt. 2, the exacerbation of the depression of hematocrits by vanadium deprivation was much less in rats fed 8.5 rather than 3.0 mg cystine/g diet. Dietary vanadium had little effect on depressed hematopoiesis in severely iron-deficient rats. The findings indicated that vanadium neither substitutes for iron at some metabolic site, nor stimulates iron absorption; but has a positive influence on the utilization of iron after absorption.

Solid-liquid separation after liquid-liquid extraction: spectrophotometric determination of iron(II) by extraction of its ternary complex with 2,2′-dipyridyl and tetraphenylborate into molten naphthalene

A method for the spectrophotometric determination of iron(II) after extraction of its ternary complex with 2,2′-dipyridyl and tetraphenylborate into molten naphthalene has been developed. Iron(II) reacts with 2,2′-dipyridyl to form a water-soluble coloured complex. This complex cation forms a water-insoluble stable ternary complex in the presence of sodium tetraphenylborate, which is easily extracted into molten naphthalene in the pH range 2.8–7.6 by vigorous shaking for a few seconds. The solid naphthalene containing the iron 2,2′-dipyridyl tetraphenylborate complex is separated by filtration and dissolved in acetonitrile. The absorbance is measured at 521 nm against a reagent blank. Beer's law is obeyed in the concentration range 2.2–65.5 µg of iron in 10 ml of acetonitrile solution. The molar absorptivity and Sandell's sensitivity are 8.89 × 103 l mol–1 cm–1 and 0.006 3 µg cm–2 at 521 nm, respectively. The interference of various ions has been studied in detail. The method has been applied to the determination of iron in standard metallic samples and the results are compared with those obtained by the 1,10-phenanthroline method.

Enrichment and Determination of Trace Amounts of Iron as the Colored Complex on the Thin Layer of Ion-exchange Resins

Abstract A trace amount of iron was extracted as the complex with 4,7-diphenyl-1,10-phenanthrolinedisulfonic acid from aqueous solution using finely divided anion and cation exchange resins. The mixed resins were collected on a filter paper as the disk of thin layer. The colored complex in the resin phase was determined with the use of a densitometer at 540 nm. The calibration graph was linear over the range 0.1–0.5 μg of iron(II). The relative standard deviation for 0.5 μg of iron(II) in 50 ml of the test solution was 2.1% (n=5). The method was applied to the trace determination of total iron in water samples.

Spectrophotometric and analogue derivative spectrophotometric determination of micro-amounts of iron with 2,2′-dipyridyl-2-benzothiazolylhydrazone

The synthesis of 2,2′-dipyridyl-2-benzothiazolylhydrazone (DPBH), characteristics, reactions with various metal ions and its application in the selective determination of iron are presented. DPBH reacts with iron(II) to form a stable 1:3 metal to ligand complex having absorption maxima at 427 and 615 nm in 0.4% Triton X-100 solution. A solution of the complex gives a constant absorbance in the pH range 4.5–8.4 at 427 nm and 3.0–9.6 at 615 nm. The molar absorptivity, sensitivity for an absorbance of 0.001 and relative standard deviation for 10.3 µg of iron (10 replicates) are 3.41 × 104 and 1.23 × 104 l mol–1 cm–1, 1.64 and 4.54 ng cm–2, and 0.7 and 0.5% at 427 and 615 nm, respectively. Application of the proposed method to the determination of iron in water samples and further sensitisation of the method by employing analogue derivative spectrophotometry are also described.

Spectrophotometric determination of iron(II) with zinc(II) complex of the Schiff base derived from pyridine-2-aldehyde and diethylenetriamine.

Zinc (II) complex of the Schiff base derived from pyridine-2-aldehyde and diethylenetriamine (BPA-Zn) was synthesized and used for spectrophotometric determination of iron(II). The BPA-Zn reacts with iron(II) to form the red complex having an absorption maximum at 525nm in the presence of a large excess of hydroxylamine. The maximum and constant absorbance of the complex is obtained in the pH range from 5.4 to 6.0. Beer's law holds for 3.5 to 69.8μg iron in 25ml. The molar absorptivity is 1.24×104 cm-1 mol-1 l. The proposed method was applied to the determination of total iron in some water samples.

Interactions among nickel, copper, and iron in rats

In two fully-crossed, three-way, two-by-three-by-three, factorially arranged experiments, female weanling rats were fed a basal diet supplemented with iron at 15 and 45 μg/g, nickel at 0, 5, and 50 μg/g, and copper at either 0, 0.5, and 5 μ/g (Expt. 1) or 0, 0.25, and 12 μg/g (Expt. 2) A gram of basal diet contained in Expt. 1 approximately 16 ng of nickel, 2.3 μg of iron, and 0.47 μg of copper; and in Expt. 2, 20 ng of nickel, 1.3 μg of iron, and 0.39 μg of copper. Expt. 1 was terminated at 11 weeks, and Expt. 2 at 8 weeks because, at those times, some rats fed no supplemental copper and the high level of nickel began to lose weight, or die from heart rupture. The findings demonstrated that relationships are complex among nickel, copper, and iron. Nickel interacted with copper and this interaction was influenced by dietary iron. Signs of copper deficiency were more severe when nickel was supplemented to the diet provided that copper deprivation was neither very severe nor mild. Iron deprivation apparently enhanced the antagonism by exacerbating copper deficiency. Signs of copper deficiency that were made more severe by nickel supplementation were depressed weight gain (Expt. 2), hematocrit (Expt. 1), hemoglobin, and plasma alkaline phosphatase activity; and elevated ratios of heart wt/body wt, kidney wt/body wt, and liver wt/body wt. Because nickel and copper have similar physical and chemical properties, the interactions between those two elements were probably the result, of isomorphous replacement of copper by nickel at various functional sites that interfered with some biological processes.

Use of ascorbic and thioglycollic acids to eliminate interference from iron in the aluminon method for determining aluminium

The use of ascorbic and thioglycollic acids as inhibitors for the interference of iron in the aluminon method of Hsu have been examined. The use of ascorbic acid, as proposed by Jayman and Sivasubramaniam, has been found to change iron interference from positive to negative causing aluminium to be underestimated. However, the addition of 0.2 ml of a 1%V/V solution of thioglycollic acid to solutions containing aluminium in amounts ranging from 10 to 50 µg has been proved to suppress the interference from up to 900 µg of iron.

Spectrophotometric determination of a small amounts of iron(II) using α, β, γ, δ-tetraphenylporphine trisulfonate

α, β, γ, δ-Tetraphenylporphine trisulfonate (TPPS) reacts with iron(II) to form complex of the 1 : 1 molar ratio between TPPS and iron(II). The complex is stable in the pH range of 3.9 to 4.2 and the apparent stability constant is 7.2 as logK at pH 4.0 and ionic strength 0.010. Iron(II) in the range of (1.09.0) μg/50 ml is determined and the sensitivity is 0.48 ngFe(II) cm-2 for 0.001 absorbance, and the molar absorption coefficient is 1.4 ×105 dm3 mol-1 cm-1. Because iron(III) reacts with TPPS in the presence of L-ascorbic acid as a reductant, iron (II) and (III) are successively determined using L-ascorbic acid. Many cations, such as Mn(II), Co(II), Cu(II), Zn(II), Pd(II), Sn(II), etc. interfere on the equivalent mole of iron(II). Take 10 ml of the sample solution containing (1.09.0) μg of iron(II) into a 50-ml Erlenmeyer flask, and add 5 ml of 0.1 M acetate buffer solution to adjust pH to 3.94.2, and 5 ml of 5×10-5 M TPPS solution. Immerse the flask in a boiling water bath for 150 min and cool to room temperature. Transfer the solution in the flask into a 50-ml measuring flask and dilute to the mark with water. Measure the absorbance at 395 nm against water.