Non-volatile

The urine of male mice contains high levels of MUPs, which play an important role in scent commimication. Male mice excrete higher levels (up to 20mg/ml urine) in their urine than females, and secretion increases with sexual 

The scent mark of the saddle-back tamarin, Saguinusfuscicollis, contains water-soluble proteins. The major protein (66kDa) of the scent mark occurs in the urine, while another major protein (ISkDa) derives from gland secretions. If the proteins are removed by enzymatic degradation, tamarins still discriminate scent marks from different donor types. However, they are able to discriminate scents with intact proteins from those with the proteins digested. Consequently, the proteins are most likely an integral part of the scent image (Belcher et ah, 1990). 

Proteins also occur in many excretions and glandular secretions, from turtles to mice and humans. Intensive studies are clarifying their role in signaling. In axillary secretion from hrunan males, the main odoriferous acid, (E)-3-methyl-2-hexanoic acid, (E)-3M2H for short, is bound to two apocrine secretion-binding proteins (ASOBl and 2) of molecular masses 45 and 26kDa, respectively. The 

ASOB2 is apolipoprotein D (apoD) of the lipocalin or Q 2n-microglobulin superfamily of carrier proteins (Preti etal, 1992 Zeng etal, 1996a,b). 

The female elephant pheromone (Z)-7-dodecenyl acetate occurs bound to urinary proteins. When it is taken up by a male elephant, the acetate is bound to proteins of the trunk mucus. This might facilitate transport of the pheromone to the vicinity of the sensory epithelium of the vomeronasal organ (Rasmussen and Schulte, 1998). 

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In analogy to the gas, the reference state is for the ideally dilute solution at c, although at the real solution may be far from ideal. (Teclmically, since this has now been extended to non-volatile solutes, it is defined at... 

In addition to the volatile silanes, silicon also forms non-volatile hydrides with formulae (SiHj) , but little is known about their structure. Silicon, however, does not form unsaturated hydrides corresponding to the simple alkenes. 

Tellurium dioxide, Te02, is a white non-volatile solid obtained when tellurium is burnt in air. It is only slightly soluble in water but dissolves in alkalis to form salts. 

These are halides formed by highly electropositive elements (for example those of Groups I and II, except for beryllium and lithium). They have ionic lattices, are non-volatile solids, and conduct when molten they are usually soluble in polar solvents in which they produce conducting solutions, indicating the presence of ions. 

When an element has more than one oxidation state the lower halides tend to be ionic whilst the higher ones are covalent—the anhydrous chlorides of lead are a good example, for whilst leadfll) chloride, PbCl2, is a white non-volatile solid, soluble in water without hydrolysis, leadflV) chloride, PbC, is a liquid at room temperature (p. 200) and is immediately hydrolysed. This change of bonding with oxidation state follows from the rules given on p.49... 

Distillation. If the impurities in a liquid are non-volatile, the liquid may be purified by direct distillation, the impurities remaining in the distilling-flask. This process is therefore essentially the same as a simple distillation for boiling-point determination, and has been already described on pp. 7-9. 

Heat a small portion of the following substances on an inverted porcelain or stainless steel crucible lid. At first, heat one side of the lid gently so that the heat travels along the lid to the organic substance later heat the lid more strongly. Note carefully in particular [a) the change in appearance, (b) whether readily inflammable, (r) any odour produced, (d) wliether a non-volatile residue is left. 

Note, (i) Care should be taken to distinguish between a residue of carbon which may be very difficult to bum off completely, and a really non-volatile residue due to the presence of a metallic derivative. Thus for instance starch leaves a hard black residue of carbon which can best be burned away by moistening with a saturated solution of ammonium nitrate and then reheating. 

Lassaigne s test is obviously a test also for carbon in the presence of nitrogen. It can be used therefore to detect nitrogen in carbon-free inorganic compounds, e.g., complex nitrites, amino-sulphonic acid derivatives, etc., but such compounds must before fusion with sodium be mixed with some non-volatile nitrogen-free organic compound such as starch... 

Glycol gives the non-volatile oxalic acid. After heating the mixture under reflux for 10 minutes, transfer 2 ml. of the cold product to a test-tube and add 4 ml. of cone. H2SO4. Note the production of carbon monoxide and carbon dioxide on heating (p. 350). 

Note. When this test is applied to amino-acids, e.g. glycine, anthranilic acid, ulphanilic acid, no odour is detected owing to the non-volatility of the acidic isocyanide in the alkaline solution. 

Physical Properties. Both solids, freely soluble in hot water, sparingly in cold water. o-Nitrophcnol, bright yellow, volatile in steam, odour resembling both that of phenol and of nitrobenzene />-m trophenol, colourless when pure, non-volatile in steam, odourless. 

Ester of an alcohol Alcohol (volatile) Na salt of a carboxylic acid (non-volatile). 

Sand. Buckets of dry sand for fire-extinguishing should be available in the laboratory and should be strictly reserved for this purpose, and not encumbered with sand-baths, waste-paper, etc. Most fires on the bench may be quickly smothered by the ample use of sand. Sand once used for this purpose should always be thrown away afterwards, and not returned to the buckets, as it may contain appreciable quantities of inflammable, non-volatile materials e.g., nitrobenzene), and be dangerous if used a second time. 

Fractional distillation. The aim of distillation is the separation of a volatile liquid from a non-volatile substance or, more usually, the separation of two or more liquids of different boiling point. The latter is usually termed fractional distillation. The theoretical treatment of fractional distillation requires a knowledge of the relation between the boiling points, or vapour pressures, of mixtures of the substances and their composition if these curves are known, it is possible to predict whether the separation is difficult or easy or, indeed, whether it will be possible. 

When dealing with esters of water-soluble, non steam-volatile, poly-hydric alcohols e.g., ethylene glycol or glycerol), the distillate consists of water only (density 1 00). The water soluble, non-volatile alcohol may be isolated by evaporation of the alkahne solution to a thick syrup on a water bath and extraction of the polyhydric alcohol from the salt with cold ethyl alcohol. 

Complete hydrolysis may be efiected by boiling either with 10 per cent, sodium hydroxide solution or with 10 per cent, sulphuric acid for 1-3 hours. It is preferable to employ the non-volatile sulphuric acid for acid hydrolysis this... 

The essential basis of the scheme for the separation of water-soluble compounds is, therefore, distillation of (a) an aqueous solution of the mixture, (b) an alkaline (with sodium hydroxide) solution of the mixture, and (c) an acidic (with sulphuric oj phosphoric acid) solution of the mixture. The residue will contain the non-volatile components, which must be separated from inorganic salts and from each other by any suitable process. 

The following are examples of the above procedure. A mixture of diethylamine and re-butyl alcohol may be separated by adding sufficient dilute sulphuric acid to neutralise the base steam distillation will remove the alcohol. The amine can be recovered by adding sodium hydroxide to the residue and repeating the distillation. A mixture of diethyl ketone and acetic acid may be treated with sufficient dilute sodium hydroxide solution to transform the acid into sodium acetate and distilling the aqueous mixture. The ketone will pass over in the steam and the non-volatile, stable salt will remain in the flask. Acidification with dilute sulphuric acid hberates acetic acid, which can be isolated by steam distillation or by extraction. 

Separations based upon differences in the physical properties of the components. When procedures (1) or (2) are unsatisfactory for the separation of a mixture of organic compounds, purely physical methods may be employed. Thus a mixture of volatile liquids may be fractionally distilled (compare Sections 11,15 and 11,17) the degree of separation may be determined by the range of boiling points and/or the refractive indices and densities of the different fractions that are collected. A mixture of non-volatile sohds may frequently be separated by making use of the differences in solubilities in inert solvents the separation is usually controlled by m.p. determinations. Sometimes one of the components of the mixture is volatile and can be separated by sublimation (see Section 11,45). 

The residue (5) in the distilhng flask may stUl contain a water-soluble, non-volatile acid. Cool the acid solution, neutralise it with dilute sodium hydroxide solution to Congo red, and evaporate to dryness on a water bath under reduced pressure (water pump). Heat a httle of the residual salt (G) upon the tip of a nickel spatula in a Bunsen flame and observe whether any charring takes place. If charring occurs, thus... 

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