Soda-lime test

The Soda- lime Test. Certain classes of nitrogenous organic compounds (e.g., amides, etc.) evolve ammonia when heated with soda-lime. In view of the limited application of this test, however, it may well be reserved for Section 3, where it is included with other compounds reacting with soda-lime. 

Salicylate, (i) Violet colouration with FeCl3 solution, discharged by mineral acids (IV.40, 5), and soda lime test (IV.40, 7). (ii) Oil of winter-green test (IV.40, 2). 

A number of nitrogen compounds, for example, proteins, do not yield cyanide ions easily with sodium fusion. It is advisable to perform the soda lime test for nitrogen if the sodium fusion shows absence of cyanide ion. 

Polymerization of cis- or trans-pentadienes as inclusion compounds with deoxycholic acid, by y-irradiation, gave optically active polymers.The electrochemical determination of vitamin D in the presence of vitamin A has been explored. Substantial losses of corticosterone and its 11-deoxy-derivative occurred when methanolic solutions were evaporated in soda-lime test tubes, although borosilicate tubes were satisfactory. The fire and explosion hazards have been assessed for a variety of commercial steroids in aerosol form. A review of... 

The Soda Lime Test. In a 10 x 75-mm test tube, mix about 50 mg of soda lime and 50 mg of Mn02- Add 1 drop of a liquid unknown or about 10 mg of a solid unknown. Place over the mouth of the tube a moist strip of Brilliant Yellow paper (moist, red litmus paper is an alternative). Using a test tube holder, hold the tube at an indine pointing away from you and others) and heat the contents gently at first and then quite strongly. Nitrogen-containing compounds will usually evolve ammonia. 

Chemical Tests. Chemical classification tests (Chapter 9), such as the ignition test and the soda lime test (or sodium fusion test), may also be conducted to further establish the identity of the product. The hydroxamate test may be used to establish the presence of the amide functional group. 

Only the a-amino-acids, which are the commonest, will be considered. Many are soluble in water, but not in ether, and are almost neutral. They dissolve in alkalis and acids, (amphoteric). They decarboxylate in the soda-lime test, evolving amines. 

In the soda-lime test, 0- and p-nitro-amines evolve ammonia. The nitro-group(s) may be detected by the usual classification tests, though it must be remembered that when reduced with tin and hydrochloric add, nitro-amines give diamines (or polyamines), and these may not react normally with nitrous acid (see page 69). 

Nitriles liberate ammonia much more slowly than amides, and in the soda-lime test distil partly unchanged. 

The soda-lime test (preliminary tests) decomposes acylated bases into the base and the parent acid, though the latter may then be decarboxylated to a hydrocarbon. Hydrolysis of these compounds by alkali is often slow, and the following method is preferable. 

In the soda-lime test (preliminary examination) nitro-com-pounds may be reduced to a small extent to the corresponding amine. 

Sulphonamides are crystalline solids. Those derived from ammonia or a primary amine are soluble in alkalis (see below). In the soda-lime test (preliminary examination) sulphonamides evolve ammonia or an amine depending on whether they are simple (RSO2NH2) or substituted (RSO2NHR, RS02NR R") respectively. Sulphanilamides give ammonia and an amine. 

Heating uith soda-lime. See Section 3, p. 3 7. test is particularly useful for providing evidence of ... 

An additional useful test is to distil the acid or its sodium salt with soda lime. Heat 0.5 g. of the acid or its sodium salt with 0 2 g. of soda lime in an ignition tube to make certain that there is no explosion. Then grind together 0-5 g. of the acid with 3 g. of soda hme, place the mixture in a Pyrex test-tube and cover it with an equal bulk of soda hme. Fit a wide dehvery tube dipping into an empty test-tube. Clamp the tube near the mouth. Heat the soda lime first and then the mixture gradually to a dull-red heat. Examine the product this may consist of aromatic hydrocarbons or derivatives, e.g., phenol from sahcyUc acid, anisole from anisic acid, toluene from toluic acid, etc. 

Mercury. Upon heating a mixture of the compound with soda lime in a long test-tube, a bright metallic mirror and, finally, drops of mercury will form in the upper part of the tube if mercury is present. 

Contains Nitrogen.—First test the original solid ni liquid by heating in a hard-glass tube with soda-lime (p. 2), and notice if the smell is that of ammonia (ammonia salt, amide or cyanide), an amine (amine or amino-acid) or a pyridine base (alkaloid). 

The USP stipulates a test and limits for alkali extraction from container soda-lime glass (5). Specially prepared double-distilled water is used to extract the glass for one hour at 121 °C in a steam autoclave on a strict cycle program. An aliquot of the extract is then back titrated with... 

Depyrogenated soda-lime (flint) 10 x 75 test tubes Depyrogenated borosilicate 13 x 100 mm test tubes Test tube rack... 

Carry out a preliminary soda lime fusion test to determine whether the base is liberated under these conditions if it is, repeat the experiment with 1 g. of the substance. Identify the base (amine) by its m.p. (if a solid) and the preparation of a solid derivative (Section IV,100). 

---