Subject octyl phase

In reverse-phase chromatography, which is the more commonly encountered form of HPLC, the stationary phase is nonpolar and the mobile phase is polar. The most common nonpolar stationary phases use an organochlorosilane for which the R group is an -octyl (Cg) or -octyldecyl (Cig) hydrocarbon chain. Most reverse-phase separations are carried out using a buffered aqueous solution as a polar mobile phase. Because the silica substrate is subject to hydrolysis in basic solutions, the pH of the mobile phase must be less than 7.5. 

Distillation with reaction, where the normal process is coupled with a liquid phase reaction, is also interesting and esterifications of certain alcohols with acids are typical industrial applications. These include, among others the homogeneously catalyzed butyl acetate process and the production of the plasticizer di-octyl-phthalate from phthalic anhydride and 2-ethyl-hexanol. However, the subject which involves both product formation and separation aspects has not usually been treated in the literature relating specifically to "mass transfer with reaction". 

---