Sulfonates Coates’cation

Electrodes doped with mediators are also successful in analyses using NAD (P)-dependent dehydrogenases (86-88). In these cases, the mediator is firmly adsorbed to the electrode. The cofactor is oxidized by the mediator, which becomes reduced. The mediator is reoxidized by an electrochemical process on the electrode. This technology makes it possible to reduce the amount of cofactor needed, for example, in flow injection analysis and also eliminates the need for enzymatic regeneration systems. A further successful development uses a carbon paste chemically modified with a dehydrogenase, the coenzyme, and a phenoxazine mediator. This complex structure is then coated with a polyester sulfonic acid cation exchanger (86). The mediators used are of aromatic polycyclic structure and are firmly bound to graphite or other carbon electrodes (Fig. 2) (89). 

A separation of alkali metal ions was first attempted in water alone using a lightly sulfonated macroporous cation exchanger with aqueous 3 mM methane-sulfonic acid as the eluent Under these conditions the sample cations exhibited very similar retention times. When the macroporous resin column was used with the same acidic eluent in 100% methanol, the chromatographic separation was improved considerably, as the alkaU metal ions were solvated with methanol and the resin matrix was probably coated with a thin layer of methanol, which made the ions and the resin surface more compatible with one another. 

Happily, the sulfonate ionizes to give a stable ion at low temperature in superacid and the case is settled, because the spectrum consists of exactly the three signals required for a delocalized structure no more and no fewer. Coates cation is a three-carbon, two-electron system, there is no doubt about it. 

Antistatic coatings Copolymers with styrene sulfonate units, cationic polyelectrolytes ... 

Serizawa and Akashi [95] analyzed the monolayer adsorption of polystyrene latex particles with cationic polyvinylamine grafted on their surface, while Serizawa et al. [96,97] used commercial anionic latex particles. Both types of particles were adsorbed on polyelectrolyte-coated substrates previously prepared by alternating adsorption of cationic and anionic polyelectrolytes such as polyallylamine hydrochloride (PAH) and polystyrene sulfonate sodium salt (PSS) according to the method described by Decher [164]. Using... 

The surface of a carbon electrode was at first coated with a thin film of an anionic polymer such as sodium poly(styrene-sulfonate) 95) or nafion 96) (thickness thousand A) then the cationic Ru(bpy)2+ was adsorbed in the anionic layer electrostatically. The modification was also made by coating water insoluble polymer pendant Ru(bpy)2 + ( ) from its DMF solution 97). These Ru(bpy) +/polymer modified electrode gave a photoresponse in the MV2+ solution with the Pt counter electrode 95-97) The time-current behaviours induced by irradiation and cutoff of the light under argon are shown in Fig. 28. It is interesting to see that the direction of the photocurrent reversed at the electrode potential of ca. 0.4 V (vs. Ag—AgCl) under... 

Perfluoroalkyl compounds have been manufactured since the 1950s.The total production of fluorinated surfactants (anionic, cationic and neutral) was 2001 in 1979, whereas in 2000 the total production of PFOS (perfluorooctane sulfonate) alone was nearly 3000t (Shoeib et al., 2004). Together with PFOA (perfluoroocta-noic acid), PFOS is used in refrigerants, surfactants, fire retardants, stain-resistant coatings for fabrics, carpets and paper and insecticides. Surface treatments, such as protection of clothing and carpets constitute the largest volume of PFOS production (Moriwaki, Takata and Arakawa, 2003). PFOA as well is present in several... 

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