New strategy for the identification of amino acids by TLE and TLC using basic or buffered mobile phases

Summary Direct, simple and reliable means for characterization of the common amino acids, using mixtures of structural analogues of amino acids and combinations of low-voltage electrophoresis (1.04 mol dm^–3 formic acid) and chromatography (tert-butanol/methanol/pyridine/formic acid/water, 33:43:9.6:0.4:20, v/v, methanol/pyridine/formic acid/water, 70:9.6:0.4:20, v/v, or tertpentanol/methylethylketone/pyridine/water, 37.5:37.5:5:20, v/v) on amorphous cellulose thin-layer are given. The efficiency of the procedures is evaluated in various examples.Abbreviations used: TLC = thin-layer chromatography, TLE = thin-layer electrophoresis, TLP = thin-layer plate; other abbreviations: see Table I and end of text.for structural analogues of amino acids and glucosamine, see Table I.     

Two-dimensional separations and behaviour of Rauwolfia,Corynanthe and Pseudocinchona alkaloids on unmodified silica gel

Summary Very efficient procedures for separation by TLC in mild conditions of fifteen alkaloids of the Rauwolfia, Corynanthe, Pseudocinchona group are described. Questions relating to the appaent selectivity of separation systems and separation factors in polar or very polar neutral or acidic mobile phases are discussed. Proportions in solvents mixtures are v/v except where otherwise indicated. Abbreviations: TLC=thin-layer chromatography, RCP=Rauwolfia, Corynanthe and Pseudocinchona; other abbreviations: see formulaes and Fig. 1.     

Geometric scaling as traveling waves

We show the relevance of the nonlinear Fisher and Kolmogorov-Petrovsky-Piscounov (KPP) equation to the problem of high energy evolution of the QCD amplitudes. We explain how the traveling wave solutions of this equation are related to geometric scaling, a phenomenon observed in deep-inelastic scattering experiments. Geometric scaling is for the first time shown to result from an exact solution of nonlinear QCD evolution equations. Using general results on the KPP equation, we compute the velocity of the wave front, which gives the full high energy dependence of the saturation scale.