Non-volatile compounds

Karas, M. Bachmann, D. Bahr, U. Hillenkamp, F. Matrix-assisted ultraviolet laser desorption of non-volatile compounds. Int. J. Mass Spectrom. Ion Process. 1987,78, 53. 

Chemical considered Organic compounds and non-volatile compounds... 

Other chemical species in the solution or flame. These may form stable non-volatile compounds with the analyte. 

M. Karas, D. Bachmann, U. Bahr, and F. Hillenkamp. Matrix-Assisted Ultraviolet Laser Desorption of Non-Volatile Compounds. Int. J. Mass Spectrom. Ion Proc., 78(1987) 53-68. 

Flavor is one of the major characteristics that restricts the use of legume flours and proteins in foods. Processing of soybeans, peas and other legumes often results in a wide variety of volatile compounds that contribute flavor notes, such as grassy, beany and rancid flavors. Many of the objectionable flavors come from oxidative deterioration of the unsaturated lipids. The lipoxygenase-catalyzed conversion of unsaturated fatty acids to hydroperoxides, followed by their degradation to volatile and non-volatile compounds, has been identified as one of the important sources of flavor and aroma components of fruits and vegetables. An enzyme-active system, such as raw pea flour, may have most of the necessary enzymes to produce short chain carbonyl compounds. 

Non volatile organic compounds are not amenable for gas chromatography. However, some types of non volatile compounds, upon pyrolysis, yield volatile products which are characteristic of the original substance and can be used as a basis of a method for estimating these substances. 

The ELSD is not plagued with the problem of baseline shift and is significantly more sensitive however it presents other disadvantages, such as the strong non-linearity of the detector response and the possibility of interference from non-volatile compounds in the sample matrix [87]. The HPLC method using traditionally reversed-phase solvents and a hybrid column/pre-column has demonstrated the separation of ethoxylated homologues of broadly distributed linear AEOs... 

Flame ionization 1 ng ml -, 10 pA All purpose suitable for saccharides and non-volatile compounds... 

Nylon microwave and roasting bags were reported to release, at cooking temperatures, volatile compounds, such as Nylon 6,6 cyclic monomer and cyclic oligomers up to the tetramer, and Nylon 6 monomer and cyclic oligomers up to the octamer. The same non-volatile compounds (except Nylon 6 heptamer and octamer) were extracted from the same packages (Soto-Valdez et al., 1997). 

Most of the direct and indirect (transport) interfaces described here use chemical ionization (c.i.) ion-sources, which are not well suited to such polar, non-volatile compounds as tri- and higher oligosaccharides. The thermospray interface, which can operate on an ion-evaporative mode, is capable of producing intact molecular ions from such nonvolatile, polar molecules and should be useful in oligosaccharide analysis. Molecules of this type, however, can also be easily analyzed by fast-atom-bombardment ionization, and use of this technique, coupled to direct liquid introduction and moving-belt interfaces, has been reported. The latter system has been applied to complex oligosaccharide analysis. ... 

The apparatus for electrolytic reductions (Fig. 5) may be an open vessel for work with non-volatile compounds, or a closed container fitted with a reflux condenser for work with compounds of high vapor pressure. Since the elec-... 

The beginning formation of small volatile hydrocarbons is associated with the formation of about the same amount of non volatile compounds retained on the catalyst. These adsorbed hydrogen deficient hydrocarbons increase the rate of methanol consumption. They are part of the reacting system. 

Autocatalysis and retardation are moderated by the pore structure of the zeolite (Figs. 1 and 2) (1) The increase of reaction rate with time is slower with HZSM5 than with HUSY, because formation of non volatile compounds is... 

A number of sesquiterpenes have been demonstrated to have pronounced biological activity ( ) among the non-volatile compounds the sesquiterpene lactones are best known (M) but other oxygenated sesquiterpenes are also known to be active. For example, the role of gossypol, a dimeric sesquiterpene and structurally related compounds has been investigated (21,22). The oxygenated sesquiterpenes, shiromodiol monoacetate and diacetate, from Parabenzoin trilobum (=Lindera triloba Blume) possess potent anti feeding activity toward Spodoptera litura larvae (85). 

Semivolatile and non-volatile compounds of wood change the colour of the distillate and contribute to an up-rounded flavour. The wooden barrels which are permeable allow air to pass in and cause ethanol to evaporate thus, the ethanol content decreases and the aroma gets more intense, complex, and concentrated. Also harsher aroma constituents are removed and the spirit changes to mellow. The period of maturation depends on the size of the casks used, the alcoholic strength, as well as the temperature and humidity in the warehouse which leads to a smoother flavour. For production of neutral highly rectified distilled spirits like vodka, grain spirit, or white rum, the quality of water is of utmost importance to the flavour. In vodka production different treatments of water like de-... 

Fig. 19.2 The operation principle of the most common membrane separation processes, with membranes separating the feed (left) from the permeate phase (right). Circles and stars indicate volatile and non-volatile compounds, respectively. Driving forces acting upon solutes are indicated by arrows as gradients of pressure (P), activity (a) and electrostatic potential (V )- It shoidd be noted that all these driving forces are eventiudly based on a gradient of the chemical potential in its most general form...

Another important group is the essential oils which are manufactured mainly from herbs and spices mostly by steam distillation. The advantage of steam distillation is the fact that a clean and powerful oil can be isolated after the distillation step without waxes and other non-volatile compounds but with an odour... 

A mixture placed in an Erlenmeyer flask comprises 6 ml of silica gel and 40 ml of a solvent containing, in solution, lOOmg of a non-volatile compound. After stirring, the mixture was left to stand before a 10ml aliquot of the solution was extracted and evaporated to dryness. The residue weighed 12 mg. 

Especially thanks to these efforts, SC CO2 can be handled safely in high-pressure equipment from the laboratory- to the industrial scale. Nevertheless, its limited power to dissolve polar or non-volatile compounds represents a major drawback in most of these applications, particularly in the garment-cleaning process, where the design of CCVphilic... 

HPLC methods follow the same principles and advantages as GC-analysis. The major difference is that more polar and also non-volatile compounds can be analyzed. 

If the species of interest happens to be volatile, it can be collected in the head space or atmosphere of a closed system, and subsequently determined by gas chromatography (GC), MS, or a combination of these (GC-MS). In some circumstances it is possible to convert non-volatile compounds into a volatile form by appropriate derivativisation (e.g. by alkylation, or formation of a metal chelate). Separation and analysis can then be based on GC. Species containing elements such as Sn, Pb, Hg, As, Sb, Bi, Se or Te can be separated from the matrix by conversion into a chemically stable and volatile hydride (e.g. by treatment in acid solution, with sodium borohydride, NaBH4). Mixtures of hydrides can be separated by GC and detected by an electron capture unit, or if only one element is of interest, the volatile hydride(s) can be fed to an element-specific detector such as an AAS unit (fitted with a heated quartz tube cell). 

---