Nitrator with Dynamic Separator

All nitrators, extractors and spent acid coolers are equipped with dynamic separators which have been described above Fig. 23. 

Various enol silyl ethers and quinones lead to the vividly colored [D, A] complexes described above and the electron-transfer activation within such a donor/acceptor pair can be achieved either via photoexcitation of charge-transfer absorption band (as described in the nitration of ESE with TNM) or via selective photoirradiation of either the separate donor or acceptor.41 (The difference arising in the ion-pair dynamics from varied modes of photoactivation of donor/acceptor pairs will be discussed in detail in a later section.) Thus, actinic irradiation with /.exc > 380 nm of a solution of chloranil and the prototypical cyclohexanone ESE leads to a mixture of cyclohexenone and/or an adduct depending on the reaction conditions summarized in Scheme 5. 

While SEC aims to separate a polymeric mixture only with respect to size (hydro-dynamic volume), investigations of substituent distribution requires a separation with respect to the chemistry of the constituents. Spurlin, very early on, recognized this problem and fiactionated cellulose nitrate by repeated dissolution and precipita-tion. The fractions obtained showed increasing viscosities and, related to this, increasing flexibihty of solution-cast thin films. Saake et al. also made use of this common principle in polysaccharide isolation, in particular the (stepwise in this instance) precipitation of CMC by ethanol from aqueous solution. ... 

Figure 10 The separation of Cd(ll), Pb(ll), and Cu(ll) from matrix interferences in the certified rice flour GBW08502 on the 100x4.6 mm PRP-1 7 pm PS-DVB column. Eluent Imoll potassium nitrate, 30 mmol 1 nitric acid, and 0.25 mmol I chlorodipicolinic acid. Detection PAR at 520 nm. (Reprinted with permission from Shaw MJ, Jones P, and Nesterenko PN (2002) Dynamic chelation ion chromatography of transition and heavy metals using a mobile phase containing 4-chlorodipicolinic acid. Journal of Chromatography A 953 141-150 Elsevier.)...

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