Validation of a thin-layer chromatography/densitometry method for the characterization of invertase activity

Planar chromatography - Current practice and future prospects

Planar chromatography, in the form of thin-layer or high-performance thin-layer chromatography (TLC, HPTLC), continues to provide a robust and widely used separation technique. It is unrivaled as a simple and rapid qualitative method for mixture analysis, or for finding bioactive components in mixtures. The format of TLC/HPTLC also provides a unique method for preserving the separation, enabling further investigation of components of interest (including quantification/structure determination) separated in both time and space from the original analysis. The current practice of planar chromatography and areas of development of the technology are reviewed and promising future directions in the use of TLC/HPTLC are outlined.

μ-Thin-layer chromatography coupled with laser ablation-inductively coupled plasma-mass spectrometry using tin(II)-imprinted polymer nanoparticles as a stationary phase for speciation of tin

A unique and novel μ-thin-layer chromatography method based on Sn(II) ion-imprinted polymer (Sn-IIP) for speciation of tin ion species in water and plasma samples is introduced for the first time. For this purpose, N-allylthiourea (NATU) and ethylene glycol dimethacrylate (EGDMA) were copolymerized in the presence of Sn(II). The obtained polymer particles were identified using multiple techniques like BET, FT-IR, XRD, and FESEM. The effects of different variables such as pH of the solution, mobile phase composition, and IIP per CaSO₄ mass ratio on the separation efficiency were also evaluated. After completion of the separation process on the plate, its surface was scanned by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Under the established optimal condition, the detection limit, relative standard deviation (RSD) of responses, and linear dynamic range (LDR) of the method were obtained as 0.3 μg L^-1, 3.5%, and 0.8-900 μg L^-1 for Sn(II) and 0.4 μg L^-1, 4%, and 1-740 μg L^-1 for Sn(IV) assay, respectively. The developed method was finally applied to the speciation of tin in various water and plasma samples. Graphical abstract Schematic representation of μ-thin-layer chromatography method based on tin(II) ion-imprinted polymer (Sn-IIP) for speciation of tin ion species in water and plasma samples and scanned separated casts by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

Changes in molecular structure of chickpea starch during processing treatments: A thin layer chromatography study

To detect the changes in molecular structure of chickpea starch during processing treatments, a thin layer chromatographic method for characterizing the molecular structure of chickpea starch was developed. With this method, the components in chickpea starch could be divided into amylopectin, small linear molecules and large linear molecules, and their contents could be determined. It was found that the degrees of polymerization of the large linear molecules and small linear molecules in chickpea enzyme-resistant starch were about 40 and below 15, respectively. Furthermore, the small linear molecules were more susceptible to α-amylase hydrolysis than the large linear molecules. The results suggested that the large linear molecules and small linear molecules in chickpea enzyme-resistant starch might mainly originate from the amylose and amylopectin of native chickpea starch, respectively, based on the retrogradation properties of amylose and amylopectin and the enzymatic degradation behavior of the large linear molecules and small linear molecules.