Determination of Mercury and Bromides with 1,10-Phenanthroline Ferrous Sulfate

1951 ◽  
Vol 23 (8) ◽  
pp. 1181-1183 ◽  
Author(s):  
M Hall ◽  
Geo. Smith
Keyword(s):  
Ferrous Sulfate

A Simplified Ferrous Sulfate Method for the Determination of Vanadium in Steel.

1915 ◽  
Vol 7 (5) ◽  
pp. 419-420
Author(s):  
George T. Dougherty
Keyword(s):  
Ferrous Sulfate

scholarly journals Determination of Folic Acid in Multivitamin Preparations by Reversed Phase HPLC

2021 ◽  
Vol 11 (3) ◽  
pp. 185-192
Author(s):  
A. S. Alekseeva ◽  
M. V. Gavrilin ◽  
T. B. Shemeryankina ◽  
M. S. Smirnova ◽  
E. P. Fedorova ◽  
...  
Keyword(s):  
Folic Acid ◽  
Silica Gel ◽  
Ferrous Sulfate ◽  
Reversed Phase ◽  
Asymmetry Factor ◽  
Array Detector ◽  
Isocratic Elution ◽  
Rp Hplc ◽  
Acid Determination

A great variety of components in multivitamin preparations containing folic acid, and a variety of test methods and conditions of folic acid determination proposed by manufacturers, require alignment of test procedures for products with similar composition.The aim of the study was to compare the results of experimental verification of folic acid determination procedures which use reversed phase high-performance liquid chromatography (RP HPLC) with isocratic elution mode. Materials and methods: The Agilent 1260 Infinity II LC system with a diode array detector (280 nm), isocratic elution mode, C8- and C18-bonded silica gel chromatographic columns, model mixtures containing folic acid, cyanocobalamin, ferrous sulfate, and potassium iodide, were used in the study.Results: The lowest relative standard deviation of the folic acid peak area (RSD=0.09%), and the lowest asymmetry factor (As=1.04) for folic acid were observed for the model mixture “ferrous sulfate+folic acid+cyanocobalamin” and the following test conditions. Column: 250×4.0 mm, silica gel for chromatography, octylsilyl (C8), endcapped; mobile phase:  methanol‒phosphate buffer (12:88), pH 6.6; column temperature: 25ºС. The study demonstrated the feasibility of using these conditions for determination of pteroic acid impurity with simultaneous precipitation of interfering ferrous ions, using ethylenediaminetetraacetic acid solution, pH 9.5, as a solvent.Conclusions: RP HPLC can be recommended as an optimal aligned test procedure for determination of folic acid in combination products. It is recommended to use a solution containing folic and pteroic acids for system suitability testing.

The Volumetric Determination of Nitrates with Ferrous Sulfate as Reducing Agent

1933 ◽  
Vol 55 (4) ◽  
pp. 1454-1457 ◽  
Author(s):  
I. M. Kolthoff ◽  
E. B. Sandell ◽  
B. Moskovitz
Keyword(s):  
Ferrous Sulfate ◽  
Reducing Agent ◽  
Volumetric Determination

Determination of Uranium in Ore with Volumetry of H2SO4-TICL3-NH4VO3

2014 ◽  
Vol 511-512 ◽  
pp. 12-16
Author(s):  
Jin Hui Yang ◽  
Shi Liang Dai ◽  
Xiao Kang Pan ◽  
Li Liu ◽  
Shu Kui Zhou ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Sodium Nitrite ◽  
Ferrous Sulfate ◽  
Standard Sample ◽  
Determination Limit ◽  
Uranium Ore ◽  
Ammonium Vanadate ◽  
Excess Sodium ◽  
Better Than

The uranium ore sample is dissolve with H2SO4, HF and H2O2.Uranium (VI) is reduced to uranium (IV) by titanous. The excess titanous is oxidized with sodium nitrite and excess sodium nitrite is destroyed with urea. Uranium can be determined by ammonium vanadate volumetry in the medium of 6 mol/L sulfuric acid taking o-phenanthroline ferrous sulfate as indicators. The determination limit is 0.03%, the RSD is better than 3%, the recovery is 95~105%. The error is less than 2% compared with the standard sample of uranium ore.

Determination of Chlorate in Caustic Soda Solutions By Reduction with Ferrous Sulfate

1945 ◽  
Vol 17 (9) ◽  
pp. 533-535 ◽  
Author(s):  
Dwight Williams
Keyword(s):  
Caustic Soda ◽  
Ferrous Sulfate

A Microbial Sensor for Determination of Sulfite in Wines

1994 ◽  
Vol 77 (4) ◽  
pp. 1052-1056 ◽  
Author(s):  
Yoshiya Kawamura ◽  
Nobuko Kubo ◽  
Haruhiko Arata ◽  
Yoshio Ito ◽  
Masao Tamura ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Ferrous Sulfate ◽  
Regression Line ◽  
Oxygen Electrode ◽  
Alkaline Extraction ◽  
Wine Sample ◽  
Microbial Sensor ◽  
Autotrophic Bacteria ◽  
Sulfur Oxidizing

Abstract The method developed for determining sulfite in wines uses a microbial sensor that consists of sulfur-oxidizing autotrophic bacteria and an oxygen electrode (SO2 meter; SOM), which selectively determines free sulfite in an acidified wine sample. Total sulfite is determined after alkaline extraction; ferrous sulfate is added to the extractant to prevent oxidation. The SOM data showed a coefficient of a variation of 1 % or less (n = 5). The total sulfites in wine determined by SOM were compared with those determined by the Monier–Williams method. Excellent agreement was achieved, as indicated by the regression line for the data: Y = 1.01 X − 1.39 (r = 0.993). With SOM, sulfite can be determined rapidly and accurately with excellent repeatability.

Determination of Vanadium Valency in Roasted Stone Coal by Separate Dissolve-Potentiometric Titration Method

2012 ◽  
Vol 1380 ◽  
Author(s):  
Bao Shenxu ◽  
Zhang Yimin ◽  
Hang Jing ◽  
Yang Xiao ◽  
Hu Yangjia
Keyword(s):  
Phosphoric Acid ◽  
Titration Curve ◽  
Ferrous Sulfate ◽  
Acid Leaching ◽  
Nitrogen Atmosphere ◽  
Ferrous Ion ◽  
Water Leaching ◽  
Stone Coal ◽  
Ammonium Ferrous Sulfate

ABSTRACTStone coal is an important vanadium-bearing resource in China. Most vanadium exists in stone coal as V(III), which is stable and not easily to be extracted. The V(III) should be oxidized to V(IV) and/or V(V) by roasting with additives at high temperature and then extracted by acid leaching and/or water leaching. Hence, the vanadium valency in roasted stone coal can reflect the roasting efficiency and leaching rate. In traditional digestion process, the V(V) can oxidize V(III) in solution and this causes great error to the determination of vanadium valency. In this study, the V(IV) and V(V) in roasted stone coal is dissolved firstly in 5% of hydrochloric acid at room temperature for 1h because the V(III) embedded in crystal lattice can not dissolve in dilute acid. The acid solution containing V(IV) and V(V) is titrated by 0.02 M ammonium ferrous sulfate (AFS), and the jump in titration curve indicates the reducing of V(V) to V(IV) by ferrous ion. The volume of V(V) can be calculated according to the consumption of AFS. The total volume of vanadium can be determined by potassium permanganate oxidation-ammonium ferrous sulfate titrimetric method. Hence, the volume of V(IV) can be obtained by deducting the quantity of V(V) from the total vanadium. Secondly, the undissolved residue is digested in Teflon vessel by phosphoric acid and hydrofluoric acid at 90 °C for 2h. The digestion solution is also titrated by AFS under nitrogen atmosphere, and the jump in titration curve denotes the reducing of V(IV) to V(III) by ferrous ion in phosphoric acid medium. So, the volume of V(III) and V(IV) can be obtained in the same way. This method is characterized by high measuring accuracy and excellent reproducibility.

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