Determination of resin acid composition in rosin samples using cyclodextrin-modified capillary electrophoresis

Abstract

Rosins are used in a wide variety of industries in varnishes, adhesives, drug coatings, etc. In this project a novel capillary electrophoresis method was developed to investigate the resin acid composition of rosins. The acids were separated and the concentrations of individual acids present in gum rosin samples determined in order to investigate any links between the presence and concentration of these acids and the tendency of rosins to crystallize. The capillary electrophoresis method successfully separated nine resin acids in various rosin samples where previously they could not all be separated. Calibration curves were created to determine acid concentration. Abietic, dehydroabietic, neoabietic, pimaric, isopimaric, levopimaric, sandaracopimaric, palustric, and 7-oxo-dehydroabietic acids were separated using a 20 mM tris buffer at pH 9 containing 15% methanol 5 mM (2-hydroxypropyl)-γ-cyclodextrin 10 mM sulfobutylether-β-cyclodextrin. Their concentrations in a crystallizing and a noncrystallizing rosin sample were determined.

Capillary Electrophoresis

“…However, the structure of crystallizing rosins is still unknown. Since resin acid comprises 90% of rosin, McKeon et al developed a novel CE method to analyze resin acid components in various rosin samples . Nine resin acids were able to be separated and their concentrations determined in two different samples.…”

Preparation of composite zein/natural resin nanoparticles

“…It is widely used in industry as a component of varnishes, adhesives or drug coatings. 19 Both shellac and rosin are insoluble in water, and well soluble in concentrated aqueous ethanol. To the best of our knowledge, pre-PREPARATION OF COMPOSITE ZEIN/RESIN NANOPARTICLES 371 paration of composite zein/shellac and zein/rosin nanoparticles was thus far not investigated.…”

“…The negative charge comes from ionized carboxylic groups of esters and polyesters of polyhydroxy acids in shellac (mainly aleuritic, butolic, shellolic and jalaric acid), and from resin acids in rosin (mainly isomeric abietic acids). 19,21 Shellac and rosin nanoparticles precipitate at pH 3 and 2, respectively, as zeta potential approaches zero. Isoelectric point of zein, shellac and rosin nanoparticles, as obtained by zeta potential measurements and visual observations are given in Fig.…”

Advances in Rosin-Based Chemicals: The Latest Recipes, Applications and Future Trends

“…Compositions of gum rosin from various sources are presented in Table 1, where it can be seen that the content of abietane-type acids may vary between 64 and 87 wt.%. Such detailed composition of a rosin can be determined, e.g., by the capillary electrophoresis method [25].…”