Quaternary amine functionality

Strong- and weak-base resins exchange anions with their aqueous environment and therefore extract only metals that form anionic complexes in solution. Strong- and weak-base resins display a similar affinity for anionic species, which increases with the charge and the polarizability of the anion. Strong-base resins have quaternary amine functional groups that possess a permanent... 

In the ion exchange process the leach liquor is passed through a bed of anion exchange resin beads which are loaded with chloride or in some cases nitrate. The resin will normally be a polymer carrying quaternary amine functions and having the generalized formula Pol(NR3)x+Cl, where Pol represents a polymer chain such as styrene-divinylbenzene copolymer, R = alkyl and... 

Homopolymers, as well as random and block copolymers with PDMS, were created by a combination of polycondensation and anionic ring-opening polymerization. To convert the chlor-opropyl side groups into quaternary ammoniums, the polymer was first treated with lithium bromide to replace the chlorine with bromine. The polymer was dissolved with (3-hydroxypro-pyl)dimethylamine to create the amphiphilic quaternary amine-functionalized polymer. Bactericidal assays of statistical and block copolymers gave MIC values of 6-25 pgmr against E. coli and S. aureus, with somewhat better activity against S. aureus. 

A hydrophobic anion exchange packing material obtained by derivati-zation of silica with a mixture of chlorosilanes to give both octyl and quaternary amine functionalities, was shown to be superior for... 

Carnitine and its esters (see [1]) cannot be introduced to the mass spectrometer by gas chromatography, as they incorporate quaternary amine functions and will decompose in the attempt. Fast atom bombardment (FAB) and electrospray ionization (ESI) can use the formal charge on the quaternary amine function to advantage, as carnitine and its esters are very easily desorbed from glycerol on the FAB probe and from aerosol sprays in ESI. Eigure 7A illustrates the use of EAB in the quantitation of carnitine and its esters excreted in the urine of a patient presenting with a severe dicarboxylic aciduria associated with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency. 

Amphoteric surfactants can function either as anionic or cationic surfactants, depending on the pH of the system. They contain both anionic and cationic functions in the same moiecuie. More costiy to produce than ionic surfactants, amphoteric surfactants represent oniy about 3% of surfactant voiume in Europe and less than 1% in the United States. They are less irritating than other materials and are largely used in personal care products. A distinction can be made between amphoteric and zwitterionic surfactants. This distinction does not affect their analysis. For the analyst, a more important distinction is between am-photerics with a secondary or tertiary amine group and those containing a quaternary amine function. The former only have cationic properties when protonated at low pH, while the quaternary amines have cationic properties even under alkaline conditions. 

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