Streak Reagents for Chromatography

Abstract

A number of streak reagents, used in detecting zones of colorless substances on the chromatographic column, have been studied in regard to their usefulness in the detection of certain compounds. These reagents are all sensitive at concentrations of 0.01 molar.Several new streak reagents have been developed.

Characterization of Some Chromatographic Adsorbents

“…lALfb -[L'/2b]l°= ( )(|) -50/2Fe" (2) In this step constant pressure was assumed; although this is not strictly true, the results indicate that it is a reasonable approximation. The Fe* differs from Vc" which is the value reported experimentally.…”

“…10. Azide-Starch-Iodide Reagent (2). This is prepared by mixing equal volumes of saturated solution of iodine in 1% potassium iodide and a solution of 10% sodium azide in 1% starch.…”

“…16. 2,4-Dinitrophenylhydrazine in Hydrochloric Acid (2). A saturated solution of 2,4-dinitrophenylhydrazine in 2 M hydrochloric acid gives a strong yellow zone on a pale yellow background with ketones and aldehydes.…”

Applications of Chemisorption in Chromatographic Separations of Organic Isomers and Homologs

“…On copper sulfate, how'ever, it was red in the absence of amines and yellow in their presence. Alkaline potassium permanganate, recommended b\' LeRosen et al (22) for oxidizable materials, turned green in the presence of some amines, but did not work on copper-containing sorbents. Three new color reactions, not previously suggested as streak reagents, were employed when metal cations, used in some of the sorbents, interfered: p-Dimethylaminobenzaldehyde, in glacial acetic acid (10) of primary aromatic amines; sodium nitroprusside, in 10% acetaldehyde formed a deep blue to violet color in the presence of some amines (11); and copper(II) chloride, in butanol gave a deep blue color in the presence of some amines.…”

Immobile Phase in Chromatography on Silicic Acid-Celite

“…Streak reagents used successfully for location of various colorless compounds are described in Table I. Several streak reagents suggested by LeRosen et al (31) were tried without success; these included their numbers 1, 8, and 15 for alcohols, and 1, 9, and 16 for acetone. Presumably the concentrations on the adsorbent in the present work were below the limits of sensitivity of these tests.…”