Manganese standard solution

Manganese standard solution use manganese in oil standard as supplied by Conostan or manganese 4-cyclohexanebutyrate (see Section III). 

However, the instrument has to be calibrated with solutions of known zinc concentration (zinc standard solutions) each time it is used to measure the zinc concentrations in sample solutions. Similarly, the instrument has to be calibrated with manganese standard solutions each time it is used to measure manganese concentrations in sample solutions. In this case the solutions from the ashings and hot water extracts... 

Standard Manganese(ll) Solution. Dissolve exactly 16.901 g ACS reagent grade manganese(II) sulfate hydrate in water and dilute to 1 E. 

Discussion. In mixtures of magnesium and manganese the sum of both ion concentrations may be determined by direct EDTA titration. Fluoride ion will demask magnesium selectively from its EDTA complex, and if excess of a standard solution of manganese ion is also added, the following reaction occurs at room temperature ... 

The excess of manganese ion is evaluated by back-titration with EDTA. The amount of standard manganese ion solution consumed is equivalent to the EDTA liberated by the fluoride ion, which is in turn equivalent to the magnesium in the sample. 

Mixtures of manganese, magnesium, and zinc can be similarly analysed. The first EDTA end point gives the sum of the three ions. Fluoride ion is added and the EDTA liberated from the magnesium-EDTA complex is titrated with manganese ion as detailed above. Following the second end point cyanide ion is added to displace zinc from its EDTA chelate and to form the stable cyanozincate complex [Zn(CN)4]2- the liberated EDTA (equivalent to the zinc) is titrated with standard manganese-ion solution. 

After the second end point, add 4-5 mL of 15 per cent aqueous potassium cyanide solution (CARE), and run in the standard manganese ion solution from a burette until the colour changes sharply from blue to red. Record the exact volume of manganese(II) sulphate solution added. 

Metal-free cotton material samples were impregnated with standard solutions of iron, copper, and manganese ions containing 10 to 100 )a,g of metal per gram of cotton material. It was completely dried and 1 g of cotton sample was combusted... 

Elemental composition K 24.74%, Mn 34.76%, 0 40.50%. The compound may be identified by its dark purple color and other physical properties, and confirmed by chemical analysis for the elements potassium and manganese by AA, ICP, and other instrumental means (see Potassium and Manganese). The concentration of permanganate ion, Mn04 in aqueous solution may be determined by titration with a standard solution of oxahc acid or ferrous ion (see Reactions). 

It is based on the addition of Mn2+ solution, followed by die addition of a strong alkali to die sample in a glass-stoppered bottle. Dissolved 02 rapidly oxidizes an equivalent amount of the dispersed divalent manganous hydroxide precipitate to hydroxides of higher valence states. In die presence of iodide ions in an acidic solution, the oxidized manganese reverts to die divalent state, with die liberation of a quantity of iodine equivalent to die original dissolved 02 content. The iodine is then titrated with a standard solution of thiosulfate. The titration end point can be detected visually with a starch indicator, or by potentiometric techniques. The liberated iodine can be determined colorimetrically. 

Salem et al. [48] reported simple and accurate methods for the quantitative determination of flufenamic, mefenamic and tranexamic acids utilizing precipitation reactions with cobalt, cadmium and manganese. The acidic drugs were precipitated from their neutral alcoholic solutions with cobalt sulfate, cadmium nitrate or manganese chloride standard solutions followed by direct determination of the ions in the precipitate or indirect determination of the ions in the filtrate by atomic absorption spectroscopy (AAS). The optimum conditions for precipitation were carefully studied. The molar ratio of the reactants was ascertained. Statistical analysis of the results compared to the results of the official methods revealed equal precision and accuracy. The suggested procedures were applied for determining flufenamic, mefenamic and... 

Two samples of air are taken and collected m large stoppered bottles of some 7-litres capacity. One sample is admitted through two tubes containing respectively chromic anhydride and powdered manganese dioxide, the second sample through a tube containing chromic anhydride only. They are then shaken with a dilute standard solution of sodium nitrite rendered slightly alkaline, and the nitrite content subsequently determined colorimetrically.3... 

The method is suitable for the determination of Mn, present as methyl-cyclopentadienyl manganese tricarbonyl, in gasoline in the range 0.5— 40/igml 1. The sample is reacted with bromine then diluted with MIBK and the standards prepared in a similar manner. This ensures an equal response from the Mn species in both sample and standard solutions. 

Manganese stock standard solution 1000 mg l-1 Mn (specified as high purity reagent for AA spectroscopy). 

Manganese intermediate standard solution, 20 mg l-1 Mn pipette 5 cm3 of stock 1000 mg l-1 Mn solution into a 250 cm3 volumetric flask. Make up to volume with water, stopper and mix well. 

Set-up and optimise the AAS instrument for determinations of zinc. Calibrate the instrument with the zinc working standard solutions and measure the concentration of zinc in all the blank, check and sample solutions, as for manganese. 

Standard manganese(II) solution 1 mg/ml. Preparation as in Section 29.2.1. Hydroxylamine hydrochloride, 10% solution, freshly prepared. The solution (neutralized to pH 8 with NaOH) must be purified by scrubbing with dithizone. 

Manganese warm-up solution (lOmg/L Mn) lOmL of Mn standard solution (1.000g/L) and 5 g of HNO3 are diluted to 1L with high-purity distilled water. This solution may be used to monitor the performance of the instrument. 

The polymer is ashed in platinum. A nitric acid extract of the ash is examined by atomic absorption spectroscopy for concentrations of nickel, copper, zinc, iron, manganese, lead, cadmium and chromium at specific wavelengths. The method is calibrated against standard Solutions of the heavy metals in nitric acid. 

Manganese from a standard solution was oxidized to Mn04 and diluted sueh that the final solution contained 1.00 mg/L of Mn. This solution had an absorbance of 0.316. A 10.00 mL wastewater sample was treated to develop the Mn04 color and diluted to 250.0 mL. The diluted sample had an absorbance of 0.296. What was the concentration of Mn in the original wastewater sample ... 

Hydrazine and its salts can be titrated in solution using manganese(lll) solutions. Saits of hydrazine generally act as reductants and they can be titrated by suitable redox titrations. Under Andrews titration conditions, iodate is reduced to ICI (I2 is initially liberated). Hydrazine salts can be titrated against standard KIO3 solution. 

Hence manganese (III) sulphate solution can be standardised widi a standard solution of a reductant eg iron (II) in acid solution. The end-point can be found potentiometrically or by using a suitable redox indicator eg ferroin (iron (II) complex with 1,10-phenanthroline) which is red but turns blue when oxidised. 

Thymolphthalein complexone (thymolphthalexone). This is thymolphthalein di(methyliminediacetic acid) it contains a stable lactone ring and reacts only in an alkaline medium. The indicator may be used for the titration of calcium the colour change is from blue to colourless (or a slight pink). Manganese and also nickel may be determined by adding an excess of standard EDTA solution,... 

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