COMPARISON OF COUNTERCURRENT CHROMATOGRAPHY WITH FLASH CHROMATOGRAPHY

Studies of the separation of benzyl, phenylethyl and phenylpropyl alco hols by flash chromatography (FC) on 1.0 x 30 or 1.9 x 15 cm silica ge l columns are compared with separation by countercurrent chromatograph y (CCC) on a 1.68 mm x 24 m, 56 mL, PTFE multilayer coil. Neither adja cent pair of alcohols could be separated by FC and separation of benzy l from phenylpropyl alcohol was poor. The small coil separation by CCC provided a resolution of 0.91 to 1.01 for benzyl and phenylethyl alco hols and better than baseline resolution of phenylpropyl alcohol from either benzyl or phenylethyl alcohol. Speed, sample capacity and selec tivity of the two separation techniques are similar but resolution by CCC is enhanced by the characteristic symmetry of CCC peaks compared w ith the severe tailing observed in FC.