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A porous polystyrene-divinylbenzene resin is investigated as a support for liquid-solid column chromatography. Distribution coefficients for a series of different functional groups as a function of ethanol concentration are reported. The effect of electrolyte concentration is considered. Adsorption of phenol, nitrophenols, and mono-, di-, and trichlorophenols as a function of pH is described. An equation for predicting the distribution coefficients for organic acids as a function of pH is given. Separations of nitro and chlorophenol mixtures are possible by using a stepwise pH elution, pH gradient, or ethanol-water gradient at pH 12. Column parameters including fast flow rates, up to 11 ml/min, are examined. Separations by high-pressure chromatography are possible.Amberlite XAD-2 is a recently synthesized styrene-divinylbenzene copolymer which has a large surface area (about 300 m2/gram) and a rigid, porous structure (90 A average pore diameter). These properties, plus others which have been previously investigated (1-4) and appear in this report, suggest that the XAD-2 polymer is a very useful adsorbent for column chromatography.Several specific applications employing XAD-2 in liquid chromatography have already been reported. Since XAD-2 will take up nonpolar solvents, it should be useful as a support in column partition chromatography (1). This technique has been used for the separation of metal ion mixtures (5, 6).Applications of XAD-2 in column adsorption chromatography include the removal of colored impurities in sugar and sugar juices (7-9), of ferrichromes in sake and rice koji (10), of low-molecular weight fractions which cause meat aroma, (11, 12) and of color and odor producing contaminants in water (13-15). Specific separation 1Author to whom reprint requests should be sent.

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The results of chromium analyses on a sample of Apollo 12 fines (12070,8) and a crystalline rock (12002,145) are shown in Table VII. Excellent agreement with other reported values which show a mean value of 0.267 % chromium is obtained for the fine materials (26); the natural variation in the content of the fines appears to be about 5 % based on the standard deviations of the results. As expected, inhomogeneities in the crystalline rock are more pronounced; a value of 0.599 ± 0.024% chromium was obtained, as compared with the results of Sievers et al. (0.621 ± 0.031 %), Goles (0.56%), and Brunfelt (0.54-0.65%) (25, 27,28).