Volatile acid number

Volatile Acid Number. The volatile acid number or the Reichert-Meissl number denotes the number of c.c. of N/10-alkali required to neutralise the volatile acids, soluble in water, obtained from 5 grams of butter fat, previously melted and filtered. It is determined exactly as described in flit- chapter headed Tatty Substances (Vol. I, p. 377). 

Owing to its high content in glycerides of volatile acids, butter fat gives a very high volatile acid number, while Other animal fats and also most vegetable tills give very low values —rarely more than 1—with the exception of coconut oil, for which the value about 7-0. 

Cacao Butter.—Use is made of Polenske s method, according to which the number of c.c. of N/io-alkali required to neutralise the insoluble volatile acids is determined (Polenske number, Insoluble volatile acid number, New butter number). This number may be determined directly or indirectly. 

Volatile Acid Number. Insoluble Volatile Acid Number. ... 

Addition of cacao butter to butter raises the insoluble volatile acid number in proportion to the extent of the addition ... 

Volatile acid number (Reichert) — 25-30, exceptionally 33. That for cacao butter = 7-9, and that for vegetable oils and animal fats about 1 or rather more. 

Insoluble volatile acid number (Polenske) = 2-20-3-00 (see Table under 15, p. 42). 

The regulation passed (in Italy) in 1894 defines the conclusions to be drawn from certain of the estimations mentioned above. Thus, as regards the volatile acid number butters the fat of which requires not less than 26 c.c. of N/10-alkali are to be regarded as genuine, when there are no contrary indications less than 20 c.c. indicates adulteration values between 20 and 26 are suspicious, when the other data (age of the butter, season of the year, etc.) do not permit of a decision. In such a case it is advisable, where possible, to examine a genuine sample of butter from the same source, provided that this can be obtained shortly after the suspected butter. 

The acidic character of siUca is shown by its reaction with a large number of basic oxides to form siUcates. The phase relations of numerous oxide systems involving siUca have been summarized (23). Reactions of siUca at elevated temperatures with alkaU and alkaline-earth carbonates result in the displacement of the more volatile acid, CO2, and the formation of the corresponding siUcates. Similar reactions occur with a number of nitrates and sulfates. Sihca at high temperature in the presence of sulfides gives thiosiUcates or siUcon disulfide, SiS2. 

Male axillary odor, thought to arise from volatile acids and volatile steroids, was collected on pads worn in the armpit for 6-9 hours. Alcohol extract of these samples was applied to the upper lip of each subject and left there for at least 6 hours. The cycles of women receiving the axillary extract three times per week for an average of 13.5 weeks became less variable and the number of aberrantly long cycles was reduced. 

Water-Based Inks. Approximately 50% of all flexographic inks use water as their primary solvent and diluent. They contain vehicles based on either acrylic emulsions, or hydrosols or an alkali-soluble rosin ester having a high acid number such as partially esterified fiimurated rosin and shellac. Carboxylated acrylic polymers, usually containing some styrene, have largely replaced natural resins because they provide better abrasion and water resistance. Ammonia or other volatile amines are used to solubilize these carboxylated resins and form resin salts. The volatile alkali evaporates from the ink film, rendering the printed matter water resistant. 

The washing of the condenser and filter is then repeated three times with 15 c.c. each time of 90% alcohol and the alcoholic solution of the insoluble fatty acids, collected in the flask, titrated with N/io-alkali in presence of phenolphthalein the number of c.c. of alkali required represents the insoluble volatile add number. 

The volatile acidity is expressed as grams of acetic acid per litre, the number of c.c. of N/10-alkali being multiplied by 0-120 (or 0-240) if 50 (or 25) c.c. of the wine were taken. 

Fixed Acidity.—This is determined by difference. The volatile acidity is multiplied by 1-25 to refer it to tartaric add, the number thus obtained being subtracted from the total acidity calculated as in (1) the remainder represents the fixed acidity in grams of tartaric acid per litre. 

Polyphenylsiloxane varnishes are light-brown to brown liquids without visible mechanical impurities. The volatile content is 45-85% (depending on the brand) the acidity number is 3-15 mg KOH/g. 

Mustafaev et al. (1989) found certain parameters useful in the determination of the quality of fatty oil in coriander fruits. Drying to -16% moisture, grinding in a pirouette mill for 60 s, ageing in a thin layer for 2h for evaporation of volatile oils, comminution in chloroform in a Foss—Lett apparatus, filtration and measurement of acid number and peroxide number are better techniques to be adopted. 

Chromatographic trace reconstructed by summing the intensities of all of the detected masses in every spectrum, and used as arbitrary units along the y axis. The x axis is the spectrum number. This is an analysis of volatile acids as trimethylsilylated derivatives from the urine of a patient suffering a metabolic disorder. If asked, the computer can indicate the retention time of every peak. The peak that is pointed out is enlarged in Figure 5.15. 

Polenske number. A measure of the insoluble volatile fatty acids in a sample of fat or oil. The number of cubic centimeters of 0.1 iV alkali required to neutralize the water-insoluble volatile acids in a five-gram sample of fat or oil. 

The purpose of heat treating a solid precursor is to remove volatiles (typically water) and to convert the solid to a desirable amorphous or crystallite phase. It is during heat treatment that the precursor converts to a physically robust and chemically active catalyst. It affects such properties of the catalyst as surface acidity, number of active sites, surface area, pore structure, and crush strength. Several operations that involve heat treatment include drying, calcination, reduction, and stabilization and they are frequently employed in multiple steps before and after forming catalyst pellets. 

Both methods involve heating the lubricant to temperatures in excess of 200°C with a high volume of air being passed through the sample for extended periods of time. Despite the different approaches both methods assess the effect on the lubricant in much the same way by measuring increases in viscosity, total acid number, TAN, and insolubles content. Method 9 additionally assesses volatility loss and formation of a solidus , essentially the point at which the sample no longer flows. FTM 5308 adds the dimension of assessing the effect of the oxidised lubricant on metal test pieces, namely ... 

Trimellitic Based Alkyd and Formulation. The trimellitic based alkyd was supplied as 100% non-volatile material. The acid number as received was 43.2. Calculation showed (see below) that the degree of base neutralization recommended was 85% of theory. The typical charge for resin preparation was described as (5) ... 

---