Development of an Iinnovative and cost-effective system for sample deposition in thin layer chromatography: evaluation and application on plant extracts

Thin layer chromatography (TLC) has been used for decades in the analysis of liquid mixtures and separation of their components. It is still widespread thanks to well-known intrinsic advantages like cheapness of apparatus required, simplicity in experimental setup and use, no need of sample preparation, simultaneous analysis of different samples, visual inspection of the resulting separations, and others. TLC sample application is carried out through spots and bands application. Alongside contact deposition as spots with a glass capillary, bands application is usually achieved by means of a spray method without direct contact with the layer. In this respect, causing limited diffusion, bands deposition entails higher separation efficiency compared to spot application method, resulting suitable for complex matrices separation such as plant extracts. Nevertheless, the spray application requires commercial dedicated apparatuses that are often too expensive or unaffordable for ordinary execution of TLC in a lab, and only a few models are available on the market. The aim of this work is the development and optimization of a lab-made spray device for the application of samples as bands, in the sake of simplicity and cheapness.