Chromatography of amino acids on silica gel. I. Two-dimensional chromatography on Silufol® thin layers

Two new methods have been developed to analyze for organic pollutants in water. The first, two-dimensional gas chromatography, using post detector peak recycling (PDPR), involves the use of a computer-controlled gas Chromatograph to selectively trap compounds of interest and rechromatograph them on a second column, recycling them through the same detector again. The second employs a new detector system, a thermally modulated electron capture detector (TMECD). Both methods were used to demonstrate their utility by applying them to the analysis of a new class of potentially ubiquitous anthropoaqueous pollutants in drinking waters- -haloacetonitriles. These newly identified compounds are produced from certain amino acids and other nitrogen-containing compounds reacting with chlorine during the disinfection stage of treatment.

Download Full-text

PAPER CHROMATOGRAPHY OF COMPLEX BIOLOGICAL MATERIALS BY SOLVENT REDEVELOPMENT WITHOUT PRIOR REMOVAL OF SALTS OR PROTEINS

Canadian Journal of Biochemistry and Physiology ◽

10.1139/o60-141 ◽

1960 ◽

Vol 38 (10) ◽

pp. 1137-1147 ◽

Cited By ~ 12

Author(s):

Arthur E. Pasieka

Keyword(s):

Amino Acids ◽

Paper Chromatography ◽

Filter Paper ◽

Complex Mixtures ◽

Two Dimensional ◽

One Dimensional ◽

Equivalent Time ◽

Biological Compounds ◽

High Concentrations ◽

Subsequent Staining

A solvent redeveloping technique has been devised by which amino acids, peptides, and sugars can be separated from complex mixtures in the presence of high concentrations of salts and proteins. The separations are effected by two to four successive 18-hour solvent developments with drying between each 18-hour period before subsequent staining of the chromatograms. Better separations and resolutions are obtained by such successive 18-hour solvent developments than by one continuous solvent development for an equivalent time. The effect of these redevelopments on the separations and resolutions of biological compounds is illustrated at various stages by photographs of one- and two-dimensional chromatograms. The redevelopment technique requires filter paper sheets up to 4 ft in length for one-dimensional analytical and preparative types of chromatograms.

Download Full-text

Role of N- and C-Terminal Amino Acids in Two-Dimensional Streptavidin Crystal Formation

Langmuir ◽

10.1021/la991426y ◽

2000 ◽

Vol 16 (11) ◽

pp. 5199-5204 ◽

Cited By ~ 7

Author(s):

Szu-Wen Wang ◽

Channing Robertson ◽

Alice Gast ◽

Sandy Koppenol ◽

Todd Edwards ◽

...

Keyword(s):

Amino Acids ◽

Crystal Formation ◽

Two Dimensional ◽

Terminal Amino

Download Full-text

Two-dimensional photonic crystals increasing vertical light emission from Si nanocrystal-rich thin layers

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.213 ◽

2018 ◽

Vol 9 ◽

pp. 2287-2296

Author(s):

Lukáš Ondič ◽

Marian Varga ◽

Ivan Pelant ◽

Alexander Kromka ◽

Karel Hruška ◽

...

Keyword(s):

Photonic Crystals ◽

Light Emission ◽

Periodic Structures ◽

Normal Direction ◽

Thin Layers ◽

Two Dimensional ◽

Lattice Constants ◽

Leaky Modes ◽

Si Nanocrystals ◽

Si Nanocrystal

We have fabricated two-dimensional photonic crystals (PhCs) on the surface of Si nanocrystal-rich SiO2 layers with the goal to maximize the photoluminescence extraction efficiency in the normal direction. The fabricated periodic structures consist of columns ordered into square and hexagonal pattern with lattice constants computed such that the red photoluminescence of Si nanocrystals (SiNCs) could couple to leaky modes of the PhCs and could be efficiently extracted to surrounding air. Samples having different lattice constants and heights of columns were investigated in order to find the configuration with the best performance. Spectral overlap of the leaky modes with the luminescence spectrum of SiNCs was verified experimentally by measuring photonic band diagrams of the leaky modes employing angle-resolved spectroscopy and also theoretically by computing the reflectance spectra. The extraction enhancement within different spatial angles was evaluated by means of micro-photoluminescence spectroscopy. More than 18-fold extraction enhancement was achieved for light propagating in the normal direction and up to 22% increase in overall intensity was obtained at the spatial collection angle of 14°.

Download Full-text