The group identification of organic compounds by means of thin-layer chromatography

The group identification method was presented based on the constant differences ΔR_f and ΔR_M, calculated from the chromatographic parameters obtained in two different mobile phases. The applicability of this method was proved with higher aliphatic alcohols, acids, and esters.     

Separation of zirconium by thin-layer chromatography

The thin-layer Chromatographie separation of a number of metal ions [Sc, Y, Zr, La, Sm, Th, U(VI), etc.] with solvent mixtures of mesityl oxide, ethanol and 5M nitric acid on silica gel-cellulose (5:1) thin-layer plates is reported. Zirconium remains stationary whilst the other metal ions move with the solvent, thus allowing a selective separation of zirconium from about 20 metal ions in ratios ranging from 100:1 to 1:100. Mixtures of various metal ions can also be separated.     

Separation of carbohydrates by thin-layer chromatography

Summary The separation of 13 sugars by means of 8 solvents and one- and two-dimensional chromatography on cellulose and starch layers is described. Good results were obtained on cellulose layers.

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Zusammenfassung Die Trennung 13 verschiedener Zucker mit 8 Lösungsmitteln im Wege der ein- und zweidimensionalen Chromatographie auf Zelluloseund Stärkedünnschichten wurde beschrieben. Zelluloseschichten ergeben gute Resultate.

     

Separation of some compounds from the 1,4-benzodiazepine group by thin-layer chromatography

Summary The separation of diazepam, N-desmethyl diazepam, oxazepam and temazepam by thin-layer chromatography has been investigated. Satisfactory results have been obtained.     

Separation and identification of some common isomeric plant triterpenoids by thin-layer chromatography and high-performance liquid chromatography

Chromatographic separation of 10 triterpenoids (α-amyrin, β-amyrin, δ-amyrin, lupeol, lupenon, lupeol acetate, cycloartenol, cycloartenol acetate, ursolic acid, oleanolic acid) and 2 sterols (stigmasterol and β-sitosterol) was studied. The chromatographic techniques included silica gel and reversed-phase (C₁₈ RP) thin-layer chromatography (TLC) and C₁₈ RP high-performance liquid chromatography (HPLC) using UV and mass spectrometric (MS) detection with atmospheric pressure chemical ionization (APCI). The TLC separation of the isomeric triterpenols lupeol, α-amyrin, β-amyrin and cycloartenol was achieved for the first time using C₁₈ RP-HPTLC plates. Cycloartenol could be separated from related compounds only on C₁₈ RP-TLC but not on the C₁₈ RP-HPLC. δ-Amyrin isolated from the tomato fruit surface extract could be separated from other amyrins only by HPLC. Tandem mass spectrometry allowed discrimination between the isomers lupeol, α-amyrin, β-amyrin, δ-amyrin, cycloartenol and between lupeol acetate and cycloartenol acetate. The combination of 3 TLC methods and 2 HPLC methods enables qualitative determination of all 12 compounds and proves to be useful for the analysis of plant extracts. It is recommended that TLC screening on silica gel and C₁₈ RP be performed before HPLC analysis.     

Separation and identification of some chlorinated hydrocarbon insecticides and herbicides by two-dimensional thin-layer chromatography

Summary A simple and rapid procedure for the two-dimensional TLC separation and identification of some chlorinated insecticides and herbicides is described. The separation is carried out on silica gel G with the following solvent systems: a) benzene-glacial acetic acid-n-hexane and b) petroleum fraction b.p. 80–100°C. The identification is achieved by spraying the chromatogram with diphenylamine and irradiating with U.V. light. The following pesticides were used in the procedure: aldrin, isodrin, dieldrin, endrin, p,p-DDT, p,p-DDE, lindane, toxaphene, methoxychlor, 2,4-dichlorophenoxyacetic acid (2,4-D), 4-(2,4-dichlorophenoxyacetic acid)-butyl ester (2,4-DB), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), 4-chloro-2-methylphenoxyacetic acid (MCPA), 4-chlor-2-methylphenoxypropionic acid (MCPP) and dalapon. The herbicides 2,4-DB and MCPP could not be separated.

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Zusammenfassung Eine einfache und schnelle Methode zur zweidimensionalen dünnschichtchromatographischen Trennung und Identifizierung chlorierter Insecticide und Herbicide wird beschrieben. Die Trennung wird auf Silicagel G mit Benzol-Eisessig-n-Hexan bzw. der Benzinfraktion Kp 80–100°C durchgeführt. Die Identifizierung erfolgt durch Besprühen mit Diphenylamin und UV-Bestrahlung. Folgende Pesticide wurden untersucht: Aldrin, Isodrin, Dieldrin, Endrin, p,p-DDT, p,p-DDE, Lindan, Toxaphen, Methoxychlor, 2,4-Dichlorphenoxyessigsäure (2,4-D), 4-(2,4-Dichlorphenoxyessigsäure)-butylester (2,4-DB), 2,4,5-Trichlorphenoxyessigsäure (2,4,5-T), 4-Chlor-2-methylphenoxyessigsäure (MCPA), 4-Chlor-2-methylphenoxypropionsäure (MCPP) und Dalapon. Die Herbicide 2,4-DB und MCPP konnten nicht getrennt werden.