Step gradient elution in gel permeation chromatography. A new approach to natural products separations 

 -  Journal of Natural Products, 46(2), p.196-199, 1983 .
<br/><br/> ABSTRACT.-A stepgradient elution sequence in gel permeation chromatography has been shown to be a mild, rapid and efficient technique for initial fractionation of crude extracts of plants and invertebrates. The procedure is described, and two examples of its application are presented.