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The chromatographic behaviour of alkali and alkaline earth metals on paper treated with di(2-ethylhexyl) phosphoric acid (HDEHP) has been investigated, using acetic acid as the eluent in the range of concentrations from 2 M to 0.01 M . The quantity (1/ RinF — 1) has been related to the hydrogen ion concentration and to the effective HDEHP concentration on the paper. A behaviour similar to that show in liquid—liquid extraction with HDEHP solutions was found, provided that the acetic acid concentration was kept low. The peculiar behaviour shown with concentrated acetic acid has been discussed. No direct proportionality has been obtained between the HDEHP molarity in the solution used to treat the paper and the effective concentration of HDEHP on the paper which acts during elution. The instability of HDEHP on paper with very concentrated acetic acid has been also investigated. Some chromatographic separations of alkali and alkaline earth metals have been carried out, and others have been suggested.

Reversed-phase chromatography of alkaline earth metals on paper treated with di-(2-ethylhexyl) orthophosphoric acid (HDEHP) has been investigated, using hydrochloric acid as eluent in a range of concentrations from 10 M to 1 · 10 −4 M . The quantity (I R F —1) has been related to the hydrogen ion concentration in the mobile phase, and to the effective HDEHP concentration on the paper. The chromatographic behavious has been correlated with that of liquid—liquid extraction systems. Chromatographic separations of alkaline earths from each other, and from other cations, were performed. Two of them were obtained with acetic acid elutions.

1. 1. The reverse phase partition chromatography of several groups of steroids has been described using a cellulose acetate foil as the supporting medium. 2. 2. The sulfuric acid-induced fluorescence of steroids may be used for quantitation after chromatography on this foil. 3. 3. The recovery of cortisol from this foil averages 58%. 4. 4. Evidence is presented that the recovery of corticosterone and aldosterone remains constant for submicrogram quantities.

Reversed-phase chromatography of aluminium, gallium, indium, thallium and the transition metals of the iron group on paper treated with di-(2-ethylhexyl) orthophosphoric acid (HDEHP) has been investigated, using hydrochloric acid as eluent in a range of concentrations from 10 M to 1 · 10−4M. The quantity (i/RF — 1) has been related to the hydrogen ion activity in the mobile phase and to the effective HDEHP concentration on the paper. The chromatographic behaviour has been correlated with that in liquid-liquid extraction systems. Chromatographic separations of the above elements from each other and from additional cations such as barium, calcium, titanium, strontium, manganese, yttrium, zirconium and uranium were performed.

Reversed-phase partition chromatography of some neutral C 27 -hydroxy and keto-steroids using aqueous isopropanol as moving phase and chloroform in heptane as stationary phase is described. The method has proved useful for separating cholesterol from its autoxidation products.

Two “reversed phase” paper-chromatographic systems for the separation of urinary aldosterone are described.

The reversed-phase partition chromatographic method of Howard and Martin for higher fatty acid analysis has been extended to include the odd-numbered, n-fatty acids C9–C19. The method was applied to the analysis of the saturated, non-volatile fatty acids from four samples of bovine milk fat and the results compared with the analyses obtained by the ester-fractionation procedure; good agreement between the two methods was found. No odd-numbered n-fatty acids were detected chromatographically in the whole groups of mixed saturated fatty acids, though traces of tridecanoic acid were detected when the fatty acids from individual ester fractions were analysed chromatographically.

A system of paper chromatography has been presented in which the stationary phase is a high-boiling hydrocarbon mixture (odorless kerosene) and the mobile phase is 60% aq. propanol. This system is not only useful for separation and identification of the cholesterol class of compounds but may be conveniently used to free tissue extracts of so-called fat. The use of the system in preparative chromatography has been discussed. Special application of two color reagents, phosphomolybdic acid and phosphotungstic acid, has been described. Proper use of the former can make it fairly specific for some steroids with secondary alcohol functions. Phosphotungstic acid was shown to give a characteristic pink color with many steroids having Δ5, 3β-ol functions if warmed gently lavender a vivid lavender if heated more strongly. Certain steroids with allylic alcohol functions were also very chromogenic but with varying results. Precautions and limitations in the use of the reagents were discussed.