This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ...The resulting ash is then dissolved in a few drops of nitric acid, and the solution diluted with water. In some cases it will be found convenient to dissolve the fat under examination in ether, and to shake the ethereal solution with aeidulated water. A portion of the acid solution obtained by any of the preceding ...
Read More
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1913 Excerpt: ...The resulting ash is then dissolved in a few drops of nitric acid, and the solution diluted with water. In some cases it will be found convenient to dissolve the fat under examination in ether, and to shake the ethereal solution with aeidulated water. A portion of the acid solution obtained by any of the preceding methods is tested with sulphuretted hydrogen; the presence of lead and (or) copper, or nickel is indicated by the appearance of a black or brown precipitate or colouration. Other portions of the solution are tested (1) with potassium ferrocyanide (brown precipitate) or with ammonia (blue colouration) for copper; 2 (2) with sulphuric acid (white precipitate) or with potassium chromate (yellow precipitate, soluble in potash) for lead. For the detection and estimation of iron see below. Zinc (taken up by oils and fats from galvanised packages) and alumina are detected by the well-known methods of quantitative analysis. Copper oxide is sometimes intentionally added to oils in order to impart to them a green colour. Edible fats (such as lard), when kept in copper or lead-glazed vessels, easily take up copper or lead on turning rancid. The quantitative determination of these two metals in edible oils and fats deserves, therefore, special attention. Quantitative Determination of Copper Weigh off accurately 10 to 20 grms. of the fat under examination in a platinum dish and incinerate. Dissolve the ash in a few drops of nitric acid, dilute with water, and filter into a beaker. Heat the solution nearly to the boiling point, add pure caustic soda or potash, and heat again for a few minutes. Filter off the black precipitate of copper oxide, dry, ignite, and weigh. Another method is to stir the warmed fat thoroughly with hydrochloric acid, and pour the acid li...
Read Less
Add this copy of Chemical Technology and Analysis of Oils, Fats and to cart. $28.30, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
Add this copy of Chemical Technology and Analysis of Oils, Fats and to cart. $38.60, new condition, Sold by Ingram Customer Returns Center rated 5.0 out of 5 stars, ships from NV, USA, published 2022 by Legare Street Press.
Add this copy of Chemical Technology and Analysis of Oils, Fats and to cart. $43.06, new condition, Sold by Ria Christie Books rated 4.0 out of 5 stars, ships from Uxbridge, MIDDLESEX, UNITED KINGDOM, published 2022 by Legare Street Press.
