Thin-layer chromatography

About: Thin-layer chromatography is a research topic. Over the lifetime, 7494 publications have been published within this topic receiving 124179 citations. The topic is also known as: TLC.

Silica subsurface amine effect on the chemical stability and chromatographic properties of end-capped immobilized artificial membrane surfaces.

Abstract: The silica surface of immobilized artificial membranes containing phosphatidylcholine (IAM.PC) has approximately two aminopropyl groups per immobilized phosphatidylcholine molecule. Primary amines near the silica subsurface adsorb biomolecules and also decrease the chemical stability of IAM.PC surfaces. Consequently, subsurface amines were end-capped by several methods including silylating reagents, acetyl analogues, glycidol, methyl glycolate, short-chain anhydrides (3-6 carbons/anhydride chain), and long-chain anhydrides (10-12 carbons/anhydride chain). All end-capping reactions resulted in loss of the initially immobilized phosphatidylcholine molecule. However, the amount of PC loss during end capping was very low (for alkyl anhydride end-capping reactions) to very high (for silylation end-capping reactions). After end capping, IAM.PC showed increased chemical stability compared to non end-capped IAM.PC surfaces. The chemical stability of IAM packing material was monitored by phospholipid leaching from IAM surfaces exposed to organic and aqueous solvents using thin-layer chromatography, 1H NMR spectroscopy, infrared spectroscopy, and mass spectrometry. IAM.PC packing material end capped with long-chain anhydrides exhibited the greatest chemical stability, i.e., little or no detectable phospholipid leaching when challenged with aqueous and/or organic solvents. The chromatography of acidic and basic compounds on end-capped and non-end-capped IAM.PC surfaces was studied. Compared to non-end-capped IAM.PC HPLC columns, the chromatographic retention times of acidic compounds (deoxynucleotides) decreased after end capping. In contrast, the retention times of basic compounds (amphetamine analogues) increased on end-capped IAM.PC HPLC columns relative to non-end-capped IAM.PC HPLC columns. This indicates that these solutes have access to the silica subsurface amines during chromatography.

Determination of the mycotoxin fumonisin B1 in maize by reversed-phase thin-layer chromatography: a collaborative study.

Abstract: A simple and cost-effective method using thin-layer chromatography for the determination of the mycotoxin fumonisin B1 in maize is described. The analytical method consisted of the extraction of ground maize by shaking with methanol/water (75:25) for 60 min and clean-up of the resultant extract by means of strong anion exchange solid-phase extraction. The purified residue, formed by evaporation of the elution solvent, was reacted with fluorescamine and the fumonisin B1-derivative was separated by reversed-phase thin-layer chromatography using a developing solution of methanol/aqueous 4% potassium chloride (70:30). The derivatized FB1 was readily visualized as a greenish-yellow spot under long wavelength ultraviolet light and quantified by visual comparison with a set of similarly derivatized standards in the range 20-300 ng FB1 spotted on plate. Based on visual comparison, levels down to 0.5 mg kg(-1) were successfully estimated. The method was collaboratively studied in 14 laboratories using four duplicate maize meal samples (including a blank) and a spiked sample for determination of recovery. No significant difference was observed between mean FB1 levels by high-performance liquid chromatography or thin-layer chromatography. Based on within-laboratory relative standard deviations of 27.1-41.7% and between-laboratory relative standard deviations of 35.0-63.3%, the method can be considered semiquantitative. The mean recovery achieved by participants at a spiking level of 2.00 mg kg(-1) was 74.5%.