Amine volatile

A)Ai-dicyclohexyl-2-benzotliiazolesulfenamide (42) [4979-32-2], The cyclohexylamine derivative is preferred over /n/ butylamine [75-64-9] and morpholine sulfenamide analogues because of lower amine volatility and less nitrosamine risk respectively. 

Neutralizing capacity is not the only measure of a required amine feed rate. Once all acidic characteristics have been neutralized, amine basicity becomes the important issue because this raises the pH above the neutralization point, to a more stable and sustainable level. Consequently, in practice we are concerned with the level of amine necessary to raise the condensate pH to a noncorrosive level. This practical amine requirement is difficult to obtain from theoretical calculations because it must take account of the amine volatility, DR, and the boiler system amine recycling factor (as well as temperature). As noted earlier, the basicity of an amine has little or no relationship to its volatility or DR, so that reliable field results are probably a more important guide in assessing the suitability of an amine product than suppliers tables. 

Cavano, Robert. Amine Volatility and Flammability. The Analyst, Association of Water Technologies, Winter 1998. 

Mosier, A.R., Andre, C.E., and Viets, F.G., Jr., Identification of aliphatic amines volatilized from cattle feedyard, Environ. Sci. Technol., 7, 642, 1973. 

Pyridine has also been used as the basic catalyst and chloride acceptor for benzoylation reactions. In one procedure, amines, volatile alcohols or thiols isolated by benzene extraction, are benzoylated with pyridine (1 ml) and benzoyl chloride (0.5 ml) by shaking intermittently at room temperature for several hours. The pyridine phase is extracted with 2 M HCl and the excess benzoyl chloride is hydrolysed with water for 12 hours. After shaking with 2 M sodium carbonate to remove benzoic acid, the benzene solution is dried and concentrated for analysis [144]. Aminoglycoside antibiotics are derivatized to the benzoyl derivatives in a similar reaction using 90 fi of pyridine and 10 /il of benzoyl chloride at 80 °C for 30 minutes. The pyridine is evaporated in a stream of nitrogen and excess benzoyl chloride is converted to methyl benzoate with methanol, again at 80°C, for 10 minutes. The product is cleaned up for analysis by a rather involved solvent extraction procedure [145]. 

Along the same line, an aluminum capillary lined with quartz coated with carbon black has been evaluated for the analysis of amines. Volatile Organic Compounds (VOCs), and oil products (25). In an alternative stainless steel column format (non-glass-lined stainless steel) intfoduced by Agilent Technologies, the metal column is deactivated and thus provides inertness similar to that of fused silica. Columns of this nature, termed DB-ProSteel series, have the same o.d. as that of a standard megabore column (0.53 mm i.d.) and require no special ferrules. 

Elimination of (or minimizing) oxygen The more (OH ) is produced, the more acid and carbon dioxide contamination by is neutralized. These amines volatilize with... 

Amine volatility losses are usually not significant. DEA, DIPA, DGA, and MDEA all have very low vapor pressures at typical amine contactor and regenerator operating conditions. However, MEA has a substantially higher vapor pressure than other amines, and volatility losses in low pressure MEA contactors can be significant. In some cases, a water wash is provided for low pressure MEA contactors (See Chapter 2). Figure 3-20 can be used to estimate amine volatility losses. 

Most aromatic acid chlorides impart a strongly acid reaction when shaken with water (compare Section 111,88). All are completely hydrolysed by boiling with solutions of caustic alkalis and yield no product volatile from the alkaline solution (compare Eaters, Sections 111,106 and IV, 183). They may be distinguished from acids by their facile reactions with alcohols (compare Section 111,27), phenols (compare Section IV,114), and amines (compare Sections 111,123 and IV.lOO). 

The quinaldine is separated from any unreacted aniline and from the alkyl-anilines by treatment with acetic anhydride, basified with sodium carbonate and steam distilled. Only the primary and secondary amines are acetylated the acetylated amines are now much less volatile so that separation from the steam-volatile quinaldine (a tertiary amine) is facile. 

Hydrolysis of a substituted amide. A. With 10 per cent, sulphuric acid. Reflux 1 g. of the compound (e.g., acetanilide) with 20 ml. of 10 per cent, sulphuric acid for 1-2 hours. Distil the reaction mixture and collect 10 ml. of distillate this will contain any volatile organic acids which may be present. Cool the residue, render it alkaline with 20 per cent, sodium hydroxide solution, cool, and extract with ether. Distil off the ether and examine the ether-soluble residue for an amine. 

Hydrolysis of a sulphonamide. Mix 2 g. of the sulphonamide with 3-5 ml. of 80 per cent, sulphuric acid in a test-tube and place a thermometer in the mixture. Heat the test-tube, with frequent stirring by means of the thermometer, at 155-165° until the solid passes into solution (2-5 minutes). Allow the acid solution to cool and pour it into 25-30 ml. of water. Render the resulting solution alkaline with 20 per cent, sodium hydroxide solution in order to liberate the free amine. Two methods may be used for isolating the base. If the amine is volatile in steam, distil the alkaline solution and collect about 20 ml. of distillate extract the amine with ether, dry the ethereal solution with anhydrous potassium carbonate and distil off the solvent. If the amine is not appreciably steam-volatile, extract it from the alkaline solution with ether. The sulphonic acid (as sodium salt) in the residual solution may be identified as detailed under 13. 

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. 

Ether solution. Contains water- insoluble amines. Aqueous solution. Will possess ammo, niacal odour of water-soluble amines present. Distil as long as distillate is alkaline to recover volatile water-soluble amines. 

Note. 3. All glassware of the distillation apparatus must be rinsed before use with a dilute solution of triethylamine Or another volatile amine in diethyl ether. Traces of acid on the glass walls may cause isomerization to H2C=CH-C(OCH3)=C(CH3)(OC2H5). 

Fluorocarbons are made commercially also by the electrolysis of hydrocarbons in anhydrous hydrogen fluoride (Simons process) (14). Nickel anodes and nickel or steel cathodes are used. Special porous anodes improve the yields. This method is limited to starting materials that are appreciably soluble in hydrogen fluoride, and is most useflil for manufacturing perfluoroalkyl carboxyflc and sulfonic acids, and tertiary amines. For volatile materials with tittle solubility in hydrofluoric acid, a complementary method that uses porous carbon anodes and HF 2KF electrolyte (Phillips process) is useflil (14). 

The Wenker process (364), carried out by BASF and various other companies since the end of the 1960s, is a distinct improvement. In this process the hemisulfate of monoethanol amine, a nonvolatile, crystalline substance, is used in place of volatile 2-chloroethylamine for the alkaline cyclisation. The reaction can be carried out under pressure (365). 

Many mercury compounds are labile and easily decomposed by light, heat, and reducing agents. In the presence of organic compounds of weak reducing activity, such as amines (qv), aldehydes (qv), and ketones (qv), compounds of lower oxidation state and mercury metal are often formed. Only a few mercury compounds, eg, mercuric bromide/77< 5 7-/7, mercurous chloride, mercuric s A ide[1344-48-5] and mercurous iodide [15385-57-6] are volatile and capable of purification by sublimation. This innate lack of stabiUty in mercury compounds makes the recovery of mercury from various wastes that accumulate with the production of compounds of economic and commercial importance relatively easy (see Recycling). 

Inhalation of aerosols or heated vapors may result in irritation of the nose, throat, and upper respiratory system. Lower molecular weight and branched-chain amines are more volatile and can cause irritation if inhaled. Volatile amines are easily recognized by their unpleasant, fishy odor. 

Air Monitoring. The atmosphere in work areas is monitored for worker safety. Volatile amines and related compounds can be detected at low concentrations in the air by a number of methods. Suitable methods include chemical, chromatographic, and spectroscopic techniques. For example, the NIOSH Manual of Analytical Methods has methods based on gas chromatography which are suitable for common aromatic and aHphatic amines as well as ethanolamines (67). Aromatic amines which diazotize readily can also be detected photometrically using a treated paper which changes color (68). Other methods based on infrared spectroscopy (69) and mass spectroscopy (70) have also been reported. 

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