Modified Bentone 34, a New Addition to Stationary Phases in Gas Chromatography to Assist in Separation of Difficult Aromatic Mixtures

The Use of Organo-Clays as Gas Chromatographic Stationary Phases.

“…Anhydro retinol was prepared by the method of Shantz, Cawley, and Norris (8). As a final step in purification, the neutralized extract of anhydro retinol was chromatographed on activated alumina and eluted with 0.5% acetone in hexane.…”

“…The elution curves were as symmetrical as the curves obtained in conventional gas liquid partition chromatography; the sample volumes used were 3 µ ., which enabled commercial thermal conductivity apparatus to be used; the elution order of the xylenes ivas para, meta, ortho, [similar to that since reported by other workers (6, 8)], in contrast to para, ortho, meta, on an unmodified Bentone-34 column; and n-nonane eluted just before ethylbenzene. They also described separations using columns modified with squalane and polyethylene glycol (4, 5), and, more recently, columns modified with diisodecylphthalate and Apiezon L have been reported by Spencer (6) and Van Der Stricht and Van Rysselberge (8).…”

“…Seven 12-foot columns were prepared with 0.05, 0.1, 0.2, 0.3, 0.5, 0.6, and 2.0 parts of Silicone Oil MS 550/1 part Bentone-34/10 parts Celite. At this stage, 2,4,4-trimethylpentene-l was added to the original blend and each column was examined in turn, at vari- (3) p-xylene; (4) ethylbenzene; (5) toluene; (6) n-propylcyclohexane; (7) n-nonane; (8) 2,4,4-trlmethylpentene-l ous operating temperatures, in the manner described above. From the graphs produced, RRV's (relative to «-nonane on this occasion) of each hydrocarbon at 80°C.…”

“…Variation of relative retention volumes at 80°C. with change of proportion of modifying solvent Key to hydrocarbons: (1) m-xylene; (2) o-xylene; (3) p-xylene;(4) ethylbenzene;(5) toluene;(6) n-propylcyclohexane;(7) n-nonane;(8) 2,4,4-trlmethylpentene-l…”