Anionic surfactants overview

As an example of an anionic surfactant mixture frequently contained in detergent formulations, an AES blend with the general formula C H2 i i—O—(CH2—CH2—O) —SO3 was examined in the negative FLAMS mode. Because of the considerable differences observed between both API ionisation mode overview spectra, the ESI—FIA—MS(—) and the APCI—FIA—MS(—) spectra are reproduced in Fig. 2.5.3(a) and (b), respectively. Ionisation of this blend in the positive APCI—FIA—MS mode, not presented here, leads to the destruction of the AES molecules by scission of the O—SO3 bond. Instead of the ions of the anionic surfactant mixture of AES, ions of AE can then be observed imaging the presence of non-ionic surfactants of AE type. 

The qualitative determination of anionic surfactants in environmental samples such as water extracts by flow injection analysis coupled with MS (FIA-MS) applying a screening approach in the negative ionisation mode sometimes may be very effective. Using atmospheric pressure chemical ionisation (APCI) and electrospray ionisation (ESI), coupled with FIA or LC in combination with MS, anionic surfactants are either predominantly or sometimes exclusively ionised in the negative mode. Therefore, overview spectra obtained by FIA—MS(—) often are very clear and free from disturbing matrix components that are ionisable only in the positive mode. However, the advantage of clear... 

In subsequent sections, an overview of the limited available data for non-ionic and anionic surfactants in drinking water will be given. A discussion of the efficiency of different production processes adopted in the preparation of drinking water to remove anionic surfactants will also be provided. 

Sulph(on)ation processes. Since many of the anionic surfactants to be discussed are made by the addition of S03 to an organic substrate, it is appropriate to consider, in overview, the main processes used and the contribution of the sulphonation process to the quality and performance of the surfactant. (The term sulphonation is used here generically to describe reaction of an organic with SO3, regardless of the nature of the substrate.)... 

Chronic and sub-lethal toxicities of anionic surfactants to aquatic animals (invertebrates and vertebrates) generally occur at concentrations equal to greater than 0.1 mg/l. Table 22.13 gives an overview of the reported chronic toxicities to invertebrates, including freshwater and marine organisms. 

The anionic charge of sulfonates within the entire practical pH range of electromigration separations and the UV-absorbing capability of the aromatic moiety make CZE-based methodologies of aromatic sulfonates feasible. However, improved selectivity and resolution of positional isomers have been sought by means of interactions with CDs, " nonionic, and cationic surfactants as well as mixed micelles. An overview of the electrophoretic methods for the determination of benzene- and naphthalenesulfonates in water samples has been presented in the literature. ... 

This chapter reviews results for the adsorption of ionic surfactants onto hydro-phobic surfaces. Even with this limitation there are many possible combinations. Both anionic and cationic surfactants are considered. The hydrophobic surfaces may be either uncharged or positively or negatively charged. Thus, the electrostatic interactions between the adsorbing surface and the surfactant may be either nonexistent, attractive, or repulsive. Finally, the adsorbing materials may be either a single species or a combination of surfactants. This review is not a comprehensive overview of all of the published material on this topic. Rather it presents representative results concerning the adsorption of ionic surfactants onto hydrophobic surfaces. 

The next sections deal with four types of surfactants anionic-active, cationic-active, amphoteric and non-ionic. More information on surfactants is to be found in Sect. 18.3, in Martindale and other literature [3,4,32]. Table 23.13 gives an overview of the main surfactants that are used in small-scale preparation. 

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