Quaternary ammonium compounds sensitivity

The threat of accidental misuse of quaternary ammonium compounds coupled with potential harmful effects to sensitive species of fish and invertebrates has prompted some concern. Industry has responded with an effort to replace the questionable compounds with those of a more environmentally friendly nature. Newer classes of quaternaries, eg, esters (206) and betaine esters (207), have been developed. These materials are more readily biodegraded. The mechanisms of antimicrobial activity and hydrolysis of these compounds have been studied (207). AppHcations as surface disinfectants, antimicrobials, and in vitro microbiocidals have also been reported. Examples of ester-type quaternaries are shown in Figure 1. 

Note Tertiary amines and quaternary ammonium compounds yield stronger colors than primary amines [25]. The dipping solution can also be used as spray solution [44]. Other reagent compositions have also been reported in the literature (1, 3, 6, 12, 13, 15, 18, 21, 23, 41] In some cases the reagents have been made up in acetone [38, 39], methanol [14] or ethanol [37] and/or acidified with hydrochloric acid [3, 33, 37-40]. The concentrations of hexachloroplatinic(IV) acid have been in the range of 0.05 -0.4 those of potassium iodide between 0.5 and 24spray solution containing 2% potassium iodide and 0.23170 hexachloroplatinic(IV) acid hexahydrate in N-hydro-chloric acid is reported to yield the best coloration results with respect to detection sensitivity and color differentiation in the detection of morphine, codeine, quinine, methadone and cocaine [46]. Acidic reagent solutions have been recommended for benzodiazepines [10, 11]. Sulfones do not react [39]. 

Life-threatening anaphylactic reactions that rarely occur during general anesthesia are mostly due to neuromuscular blockers. They may be due to cross-allergy mediated by drug-specific IgE antibodies to the quaternary ammonium moiety of the neuromuscular blocker molecule, perhaps with a contribution from IgE-independent mechanisms. Quaternary ammonium compounds, such as benzalkonium, in cosmetics and toiletries may play a role in sensitization (7). 

Russell AD, Furr JR. Comparitive sensitivity of smooth, rough and deep rough strains of Escherichia coli to chlorhexidine, quaternary ammonium compounds and dibromopropamidine isethionate. Int J Pharm 1987 36 191-197. 

Both spheroplasts and protoplasts are equally sensitive to lysis by membrane-active agents such as quaternary ammonium compounds (QACs), phenols and chlorhexidine. This demonstrates that the difference in sensitivities of whole cells to these agents is not due to a difference in sensitivity of the target cytoplasmic membrane but in the different permeability properties of the overlying wall or envelope structures. 

Pig farmers have a higher incidence of asthma than the general population. Quaternary ammonium compounds (QACs) are commonly used disinfectants with no known sensitization effects. In a study of Dutch pig farmers, however, it was found that the incidence of asthmatic sensitization was much higher for those who used QACs than for those who did not use these disinfectants. I56l... 

Quaternary ammonium compounds are widely used antiseptics and disinfectants with a low sensitizing potential. Benzalkonium chloride is used as a skin disinfectant, for disinfection of instruments, and in treatment of burns, ulcers, etc. Cosmetics, deodorants, mouthwashes, and ophthalmic preparations, including contact lens solutions, may contain benzalkonium chloride. 

Although the applications described here have concerned diverse macromolecular samples, pyrolysis is also of utility in the analysis of smaller molecules, particularly quaternary ammonium compounds, which undergo quantitative thermal fragmentation to volatile products. For example, the specificity and sensitivity afforded by Py-GC/MS with mass fragmentography renders the technique suitable for the analysis of endogenous neurotransmitters such as acetylcholine at the l-2pmol level. However, in all cases, analytical throughput is limited by the retention times of the pyrolysis products, a condition that is particularly severe in taxonomic applications. Automation allows extended use, but direct Py-MS... 

Didecyidimethylammonium chloride is a quaternary ammonium compound used as detergent/disinfectant in hospitals, as algicide in swimming pools, and as a fungicide and against termites in wood. This compound caused contact dermatitis in a hospital employee, also sensitive to glyoxal and fefs-(aminop-ropyl) -laurylamine. 

In the past, these types of cationic surfactants have played only a secondary industrial role, but are increasingly employed in recent years. In the past, not many liquid chromatographic methods for separating such compounds were foimd in the literature. Because these quaternary ammonium compounds are comparably hydrophobic, hydrochloric acid is used as the ion-pair reagent in their separation. Perfluorinated carboxylic acids are also used from time to time. Because of the lack of suitable chromophores, quaternary ammonium compounds can be sensitively detected only by measuring the electrical conductivity. Figure 6.44 shows a separation of a number of aliphatic quaternary ammonium compoimds it was... 

Addition of one monomer at a later point of the reaction results in the formation of latex particles of the core-shell type [479]. For special lattices, acrylonitrile and methacrylic acid are added [480,481]. Heat-sensitive lattices contain such additives as quaternary ammonium compounds, sulfonamides, polyether urethanes, and organopolysiloxanes, which affect the coagulation of the latex above a certain temperature [482]. 

Figure 7.45(a) Interactions between detergents and quaternary ammonium compounds showing variation of bactericidal conentrations (1 part in x x 10 ) with alteration in the ratio between non-ionic and quaternary showing initial increased activity, followed by a decrease in activity. Staph, aureus shows no variation, as it is so sensitive to the quaternary compound. From [220]. (b) Bactericidal activity in non-ionic ampholyte quaternary systems. (From [220]). A = 75% non-ionic, 25% sodium dodecyl amino propionate B = 50% non-ionic, 50% ampholyte C = 25% non-ionic, 75 % ampholyte. 

Numerous nitrate ion-selective membranes (Table 2.3) have been described for various environmental applications, such as food, plants, fertilizer, soil, and waste-water. Overall, best results were obtained with PVC ion-selective membranes prepared with quaternary ammonium compounds, such as TDDA or MTDA as the sensing element. These membranes were able to determine nitrate across the concentration range important for N fertilizer applicatirm management, i.e., 10 30 mg kg NO3. The best membranes also maintained acceptable selectivity levels in mixed solutions, being at least 40 times more sensitive to nitrate than to chloride and bicarbonate. 

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