Residual volatiles

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. 

The filtrate from the crude trimyristin contains the odorous oils of the nutmeg. A further quantity of trimyristin may be obtained from it by distilling with steam and recrystallizing the non-volatile residue twice from alcohol but the amount is not commensurate with the trouble, and this operation is not advised unless the residues from at least 5000 g. of nutmegs are on hand. 

Resin is frequently found in cassia oil. It interferes with the accurate determination of the aldehyde by making it difficult to read off the uncombined oil. It may be detected by adding a solution of lead acetate in 70 per cent, alcohol to a solution of the oil in alcohol of the same strength. The presence of resin increases the amount of non-volatile residue, and also increases the acid value of the oil. 

After the hydrogen absorption ceases, the autoclave is cooled, vented, and the reaction mixture is filtered to separate the catalyst. The filtrate is then heated on a steam bath at 60-80 mm pressure to remove the dioxane. The less volatile residue consists of 1,933 parts of crude dithioglycerol, a viscous oil. 

Empirical evidence supporting the role of soil micro-layer losses in zero-time issues is given by the often-seen rise in post zero-time residue recoveries. The improved recoveries likely result from the micro-layer residue redistribution that reduces losses of the highly concentrated surface residues. There has been some speculation that zerotime core recoveries may be due to volatilization losses not measured by standard laboratory studies. If this were the case, however, increases in residue concentrations would not occur over time since volatilized residues would be lost to the atmosphere. ... 

MPE provides several advantages when compared with the use of SVE or pump-and-treat alone. MPE provides for an increase in groundwater recovery rates, an increase in ROI in individual ground-water recovery wells, and recovery of shallow free product. By depressing the groundwater table in the vicinity of the extraction wells, MPE provides for remediation of the capillary fringe and smear zone, and remediation of volatile, residual contaminants located above and below the water table.46... 

Zn(R-dtp)2 complexes have been characterized and their thermal stabilities investigated 173,184,190,297-299,301-305) Zn(R-dtp)2 compounds are thermally degraded to volatile olefins and non-volatile residues and this serves as the basis for gas chromatographic determination of the compounds 304,30s) Several papers describing pyrolyses of Zn(R-dtp>2 complexes have discussed mechanisms for formation of olefins, sulfides, and other products 173,184,190,298,299, 304) Dakternieks and Graddon i8s,283)35 mentioned earlier, have reported thermodynamic measurements for depolymerization and adduct formation reactions of zinc, cadmium and mercury R-dtp compounds. 

The performance of ISC units is affected by soil type and soil moisture content. Waste streams derived from ISC processing may consist of volatile off-gases formed during oxidation reactions and products of incomplete oxidation. Bench-scale studies have shown that volatile residuals can be created by ISC, but they have, as yet, not been fuUy characterized. 

In the schematic diagram of the vacuum line (Fig. 2.1) a U-bend is shown between the main tap T, and the manifold, which has two functions (a) It lends an extra element of mechanical flexibility to the system by absorbing small movements at the traps or along the main manifold (WL or WL ) which might otherwise lead to fracture and (b) it acts as a sink for non-volatile residues in the line and for grease which may be washed away from the taps 7, 7 and 7. ... 

Nonvolatile Matter. Evaporate 100ml of the sample on a steam bath in a tared dish (preferably platinum) and dry the residue to constant weight in an oven, maintained at 105 to 110°C. The increase in weight of dish shall be calcd as percentage non-volatile residue. Calculate as follows ... 

Non-volatile residue. Measure approx 100ml of the cold sample into a chilled 100-ml graduate and place it In n tared boro-silicate glass evaporating dish. Allow the EtnO to evaporate to dryness at RT. Place the dish in an oven at 105° to 110°C for 30 mins. Cool the dish in a desiccator and reweigh it to the nearest mg. Calculate the non-volatile residue by subtracting the care wt from the wc of the dish containing the residue... 

Salt was one of Paracelsus tria prima. Like the other principles and the four elements of the alchemists, salt as principle took its qualities as well as its name from the material bodies with the same properties. In a fire analysis, salt was to be found in the non-volatile residue and extracted from the non-soluble earth by water. This real salt demonstrated the more or less universal presence of the salt principle in all such bodies. The presence of SALT as principle accounted for the body s solidity and resistance to fire. In its material manifestation, it was recognized by its solubility and its saline taste. 

Cyanogen Trisulphide, (CN)2S3 or (CN)6S .—The non-volatile residue which is formed when silver cyanide acts on sulphur chloride constitutes cyanogen trisulphide. It is a dark yellow crystalline powder, insoluble in water, alcohol, ether, carbon disulphide and chloroform. It is unattacked by hydrochloric acid and is soluble in concentrated sulphuric acid. It is transformed into carbon dioxide and sulphuric acid by nitric acid or aqua regia. When distilled, the products are carbon disulphide, sulphur and tricyanuramide, N8(C3N3)3.1... 

Non-volatile residue (particulates) Non-volatile organic residue (oil and grease) Phosphene3... 

Batten (Refs 30, 31, 32, 47 58) studied the decompn of solid RDX over the range of 170—97°C- In agreement with Ref 26a, the major gaseous products found were N20, H20, N2, HCHO, C02, CO and NO and minor amts of N02 HCN (Ref 32). A non-volatile residue (NVR) was identified as N-hydroxymethyl-formamide, HCON(OH)CH3. Added NVR or... 

Another type of experiment has been used to assess the chemical reactivity of pesticides in the air. This principally employs downwind sampling from a treatment site during application (for measuring conversion in the spray drift) and for several days following application (for conversions involving volatilized residues) (24). The principal data are in the form of product(s)/parent ratios with increasing downwind distance, from which estimates of the rate of conversion can be made knowing the air residence time calculated from windspeed measurements. 

The test principle is such that the extraction of migratable substances from a sample of the plastics is determined as the mass of non-volatile residue after evaporation of the solvent following immersion. Test specimens of at least 1 dm2 (single side considered) are immersed in the extraction solvent at the specified test conditions and then... 

For tins reason, according to Kratz, the most rational way of removing TNT and salts of nitrosulphonic acids from the water is by simply distilling off the water and then destroying the non-volatile residue. 

Nitration grade phenol should be completely soluble in water, giving a clear solution. Not more than 0.1% of non-volatile residue left after the evaporation of phenol, when heated on a steam bath, is permissible. 

Assay and test results are determined on the basis of comparison of the test sample with the reference standard that has been freed from or corrected for volatile residues or water content as instructed on the reference standard label. If a reference standard is required to be dried before use, transfer a sufficient amount to a clean, dry vessel. Do not use the original container as the drying vessel, and do not dry a reference standard repeatedly at temperatures above 25°. Where the titrimetric determination of water is required at the time a reference standard is to be used, proceed as directed in the Karl Fischer Titrimetric Method under Water Determination, Appendix IIB. 

Citrus essential oils are widely used as a raw material of flavour in food and perfumery industries. They are also called "cold-pressed oils" and contain more than 200 compounds which can be grouped in three fractions the hydrocarbon terpenes (unsaturated compounds) that constitute the major amount (from 60 to 98% by weight) but have undesirable off-flavours characteristics the oxygenated compounds (flavour fraction) that are directly responsible for the characteristic citrus flavour and the non-volatile residues. 

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