A simple technique for the preparation of micro slides for thin-layer chromatography

Summary A simple, inexpensive apparatus and procedure are described for the rapid preparation of coated micro slides for thin-layer chromatography. Although micro slides of varying sizes may be coated in this apparatus, the commercially-available Breed Brew slide is especially advantageous since it permits more analyses to be run on each chromatoplate and offers a longer developmental pathlength. A convenient, readily-constructed marking template which can accommodate micro slides of varying sizes is also presented.

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Zusammenfassung Ein einfacher, nicht aufwendiger Apparat und ein Verfahren für die rasche Beschichtung von Objektträgern für die Dünnschichtchromatographie wurden beschrieben. Zwar können Objektträger verschiedener Größe beschichtet werden, die handelsüblichen Breed-Brew-Platten, wie sie zur Bakterienzählung verwendet werden (51×115 mm), sind jedoch besonders vorteilhaft, da mehrere Analysen mit längerer Laufstrecke auf jeder Platte gleichzeitig ausführbar sind. Eine Schablone zur Markierung von Objektträgern verschiedener Größe wurde ebenfalls beschrieben.

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Résumé On décrit un appareillage simple et peu coûteux, avec un mode opératoire pour préparer rapidement des revêtements micro pour chromatographie en couche mince. Bien que l'on puisse recouvrir des lamelles micro de diverses tailles à l'aide de cet appareil, la lame «Breed Brew» disponible dans le commerce se montre particulièrement avantageuse puisqu'elle permet d'effectuer davantage d'analyses sur chaque chromatoplaque et qu'elle offre un trajet plus long pour le développement. On présente également un modèle pratique et rapidement construit pour la graduation; il peut s'adapter aux microplaques de diverses tailles.

     

A fast radiochemical procedure for separating iodine from fission products

The iodine isotopes produced by thermal neutron fission of²³⁵U were separated by a fast chemical procedure, with a separation yield of 95%. The gamma-ray energies and relative intensities in the decay of¹³¹I,¹³²I,¹³³I,¹³⁴I and¹³⁵I were determined using a Ge(Li) detector.     

Preparation and thin-layer chromatography of bromo-derivatives of unsaturated fatty acid esters. A simple and rapid procedure for fatty acid analysis.

Bromo-addition products of unsaturated long-chain fatty acid esters have been prepared and chromatographed on thin layers of unmodified silica gel. The polarity of these derivatives was found to be directly related to the number of double bonds of the parent fatty acid from which they were derived. This has been made the basis of a simple method for assessing the relative proportions of the main fatty acid classes in a mixture.     

A simple oxidative procedure for the removal of ruthenium residues from metathesis reaction products

Ruthenium residues can be easily and rapidly removed from Grubbs metathesis products by washing with 15% aqueous hydrogen peroxide, which converts any ruthenium complexes into highly insoluble ruthenium dioxide, which then catalyzes the conversion of excess peroxide into water and oxygen. Ruthenium levels lower than 2 ppm can be routinely obtained; an additional advantage is that any phosphines are also rapidly oxidized to the corresponding, more polar phosphine oxides thereby facilitating their removal as well in many cases.     

High-performance liquid chromatography and thin-layer chromatography for the simultaneous quantitation of rabeprazole and mosapride in pharmaceutical products

Simple, sensitive high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) methods are developed for the quantitative estimation of rabeprazole and mosapride in their combined pharmaceutical dosage forms. In HPLC, rabeprazole and mosapride are chromatographed using 0.01M 6.5 pH ammonium acetate buffer-methanol-acetonitrile (40:20:40, v/v, pH 5.70+/-0.02) as the mobile phase at a flow rate of 1.0 mL/min. In TLC, the mobile phase is ethyl acetate-methanol-benzene (2:0.5:2.5, v/v). Both the drugs are scanned at 276 nm. The retention times of rabeprazole and mosapride are found to be 4.93+/-0.01 and 9.79+/-0.02, respectively. The Rf values of rabeprazole and mosapride are found to be 0.42+/-0.02 and 0.61+/-0.02, respectively. The linearities of rabeprazole and mosapride are in the range of 400-2000 ng/mL and 300-1500 ng/mL, respectively, for HPLC; in TLC, the linearities of rabeprazole and mosapride are in the range of 400-1200 ng/spot and 300-900 ng/spot, respectively. The limit of detection is found to be 97.7 ng/mL for rabeprazole and 97.6 ng/mL for mosapride in HPLC; in TLC the limit of detection is found to be 132.29 ng/spot for rabeprazole and 98.25 ng/spot for mosapride. The proposed methods can be applied to the determination of rabeprazole and mosapride in combined pharmaceutical products.