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Где найти методики? >>>
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| Автор | Тема: Где найти методики? |
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Elya Пользователь Ранг: 1 |
 16.08.2006 // 13:12:18
Нужны методики анализов на магния карбонат, марганца глюконат 2-водный и железа фумарат. Подскажите, пожалуйста, где можно найти эти методики? |
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ANCHEM.RU Администрация Ранг: 246 |
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Alex75 Пользователь Ранг: 459 |
17.08.2006 // 7:34:20
В любом практикуме по аналитической химии для ВУЗОв - если, конечно, речь идет о титриметрии. |
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Garry VIP Member Ранг: 1076 |
18.08.2006 // 10:53:41
В фармакопеях. Например в Британской : General Notices (Ph Eur monograph 0043) 546-93-0 Ph Eur Definition Hydrated basic magnesium carbonate. Content 40.0 per cent to 45.0 per cent, calculated as MgO (Mr 40.30). Characters Appearance White powder. Solubility Practically insoluble in water. It dissolves in dilute acids with strong effervescence. Identification A. 15 g has an apparent volume (2.9.15) before setting about 30 ml. B. It gives the reaction of carbonates (2.3.1). C. Dissolve about 15 mg in 2 ml of dilute nitric acid R and neutralise with dilute sodium hydroxide solution R. The solution gives the reaction of magnesium (2.3.1). Tests Solution S Dissolve 5.0 g in 100 ml of dilute acetic acid R. When the effervescence has ceased, boil for 2 min, cool and dilute to 100 ml with the same acid. Filter, if necessary, through a previously ignited and tared porcelain or silica filter crucible of suitable porosity to give a clear filtrate. Appearance of solution Solution S is not more intensely coloured than reference solution B4 (2.2.2, Method II). Soluble substances Maximum 1.0 per cent. Mix 2.00 g with 100 ml of water R and boil for 5 min. Filter whilst hot through a sintered-glass filter (40), allow to cool and dilute to 100 ml with water R. Evaporate 50 ml of the filtrate to dryness and dry at 100-105°C. The residue weighs not more than 10 mg. Substances insoluble in acetic acid Maximum 0.05 per cent. Any residue obtained during the preparation of solution S, washed, dried, and ignited at 600°C, weighs not more than 2.5 mg. Chlorides (2.4.4) Maximum 0.07 per cent. 1.5 ml of solution S diluted to 15 ml with water R complies with the limit test for chlorides. Sulphates (2.4.13) Maximum 0.6 per cent. 0.5 ml of solution S diluted to 15 ml with distilled water R complies with the limit test for sulphates. Arsenic (2.4.2) Maximum 2 ppm. 10 ml of solution S complies with limit test A. Calcium (2.4.3) Maximum 0.75 per cent. Dilute 2.6 ml of solution S to 150 ml with distilled water R. 15 ml of the solution complies with the limit test for calcium. Iron (2.4.9) Maximum 400 ppm. Dissolve 0.1 g in 3 ml of dilute hydrochloric acid R and dilute to 10 ml with water R. 2.5 ml of the solution diluted to 10 ml with water R complies with the limit test for iron. Heavy metals (2.4.8) Maximum 20 ppm. To 20 ml of solution S add 15 ml of hydrochloric acid R1 and shake with 25 ml of methyl isobutyl ketone R for 2 min. Allow to stand, separate the aqueous layer and evaporate to dryness. Dissolve the residue in 1 ml of acetic acid R and dilute to 20 ml with water R. 12 ml of the solution complies with limit test A. Prepare the standard using lead standard solution (1 ppm Pb) R. Assay Dissolve 0.150 g in a mixture of 20 ml of water R and 2 ml of dilute hydrochloric acid R. Carry out the complexometric titration of magnesium (2.5.11). Magnesium In a 500 ml conical flask dilute the prescribed solution to 300 ml with water or dissolve the prescribed quantity of the substance being examined in 5 to 10 ml of water or in the minimum volume of 2M hydrochloric acid and dilute to 50 ml with water . To the resulting solution add 10 ml of ammonia buffer pH 10.0 and about 50 mg of mordant black 11 triturate. Heat to 40° and titrate at this temperature with 0.1M disodium edetate VS until the colour changes from violet to full blue. Each ml of 0.1M disodium edetate VS is equivalent to 2.431 mg of mg. 1 ml of 0.1M sodium edetate is equivalent to 4.030 mg of MgO. |
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Garry VIP Member Ранг: 1076 |
18.08.2006 // 10:57:32
Вот на фумарат железа : Definition Ferrous Fumarate Oral Suspension is a suspension of ferrous fumarate in a suitable flavoured vehicle. The oral suspension complies with the requirements stated under Oral Liquids and with the following requirements. Content of ferrous iron, Fe(II) 90.0 to 110.0% of the stated amount. Identification A. Mix a volume of the oral suspension containing about 0.6 g of ferrous fumarate with 20 ml of water , centrifuge and discard the supernatant liquid. Repeat with a further 20 ml of water . Add 15 ml of 3M hydrochloric acid to the residue, dissolve with minimum warming, cool and extract with two 50 ml quantities of ether . Wash the combined ether extracts with two 20 ml quantities of water , shake with anhydrous sodium sulphate, filter and evaporate to dryness. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of fumaric acid (RS 163). B. Mix a volume of the oral suspension containing about 0.3 g of ferrous fumarate in 10 ml of water , centrifuge and discard the supernatant liquid. To 0.2 g of the residue add 10 ml of a mixture of equal volumes of hydrochloric acid and water , dissolve with minimum warming, cool and filter. The filtrate yields reaction A characteristic of iron salts, Appendix VI. Ferric iron Disperse a quantity of the oral suspension containing 0.28 g of ferrous fumarate in 20 ml of water , centrifuge and decant the supernatant liquid into a 500 ml graduated flask. Dissolve the residue in 20 ml of 1M sulphuric acid with minimum warming, cool and transfer the resulting solution to the same graduated flask, dilute to 500 ml with water and filter. To 5 ml of the filtrate in a Nessler cylinder add 40 ml of water and 5 ml of a 10% w/v solution of ammonium thiocyanate and mix. Any red colour produced is not more intense than that obtained by treating in the same manner a mixture of 42 ml of water , 0.2 ml of 1M sulphuric acid and 3 ml of a 0.0173% w/v solution of ammonium iron(III) sulphate in 0.01M hydrochloric acid [6.0%, with respect to the content of Fe(II)]. Assay Mix a quantity of the oral suspension containing 0.28 g of ferrous fumarate with 10 ml of water and 25 ml of nitric acid, carefully warm until the vigorous reaction subsides, add a further 25 ml of nitric acid, evaporate to about 10 ml and allow to cool. Carefully add 10 ml of sulphuric acid to the cooled solution, evaporate until white fumes are evolved, cool, add 10 ml of nitric acid and again evaporate until white fumes are evolved. Repeat the evaporation with 10 ml quantities of nitric acid until all of the organic matter has been destroyed. To the resulting solution add 10 ml of water and 0.5 g of ammonium oxalate, evaporate until white fumes are evolved, add 50 ml of water , boil until a clear solution is obtained, cool, dilute to 100 ml with water and add dilute potassium permanganate solution, drop wise, until a faint pink colour persists for 10 seconds. Add 10 ml of hydrochloric acid and 3 g of potassium iodide, allow to stand for 15 minutes protected from light, add 10 ml of chloroform and titrate the liberated iodine with 0.1M sodium thiosulphate VS, with vigorous shaking, until the chloroform layer becomes colourless. Repeat the procedure without the preparation being examined. The difference between the titrations represents the amount of sodium thiosulphate required. Each ml of 0.1M sodium thiosulphate VS is equivalent to 5.585 mg of Fe(II). Storage Ferrous Fumarate Oral Suspension should be protected from light. Labelling The quantity of the active ingredient is stated both as the amount of ferrous fumarate and in terms of the equivalent amount of ferrous iron. |
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