Anal. Chem. 60, 2692-2694 (1988). Application of fluorescence line-narrowing spectrometry (FLNS) to a polycyclic aromatic hydrocarbon-nucleoside adduct sorbed on a TLC plate. Discussion of the effects of non-photo chemical hole burning and interfacing FLNS with the 32p-postlabeling procedure to provide for high sensitivity and selectivity analysis of TLC spots associated with fluorescing nucleoside adducts. Presentation of a calibration curve over >5 decades of concentration. Detection limit, 10 f mol.

Chinese Anal. Chem. (Fenxi Huaxue) 18, 801-805 (1990). Description of a device using laser-induced photothermal deflection spectroscopy as detection technique for TLC. The detection limits for magenta and crystal violet were 0.3 ng and 0.4 ng, respectively.

10: Effect on reproducibility of the relative positions of the spots and scanning slit. J. Planar Chromatogr. 5, 164-168 (1992). Demonstration that the most significant contribution to statistical errors in TLC arises from errors in positioning as a result of unequal and inhomogeneous distribution of samples on the stationary phase, and irregular relative positioning of slit and spot during a scan.

Part XIII - Identification of residues on the surface of diffusely reflecting layers. J. Planar Chromatogr. 9, 178-180 (1996). Description of a method for quantitative evaluation, by densitometry, of unidentified contaminating residues present as small spots on the surfaces of tablets, surfaces which act as diffusely reflecting layers. - Semiquantitative results are obtained by comparison of peak areas from the tablets with calibration curves from samples applied to a dry TLC plate. The limit of detection is from 1 to 5 ng per spot, depending on the substance measured.

1. Basic algorithms of image processing. J. Planar Chromatogr. 13, 248-253 (2000). Description of the basic principles of image processing in HPTLC and TLC including the definitions of scanning densitometry and two-dimensional digitized chromatograms in terms of vector or matrix algebra. The basics of imaging processes concern pixels, color systems, and imaging operations and image processing using image-manipulation procedures such as changing the mode from color to gray-values, presenting gray-values as histograms, including equalization or contrast stretching, and two-dimensional deconvolution procedures. Further operations are also needed; the necessary algorithms and/or the principles are given in the paper.

J. Planar Chromatogr. 16, 331-337 (2003). Literature recommends dipping TLC plates in viscous liquids to enhance fluorescence. Measurement of the fluorescence and absorbance spectra of pyrene spots reveals the mechanism of enhancement of plate dipping in viscous liquids - blocked contact of the fluorescent molecules with the stationary phase or other sample molecules is responsible for the enhanced fluorescence at lower concentrations. TLC and HPTLC of pyrene on silica gel and on RP-18 with methanol - acetone 8:3. The dipping solution was prepared by dissolving 3.8 g pentane sulfonic acid in 20 mL water. Densitometry in the range of 198 to 610 nm.

Anal. Chem. 56, 595-597 (1984). Description of an indexing device for scraping bands of 5 or 10 mm width from TLC plates.

J. Chem. Educ. 72, 1137-1138 (1995). Description of an experiment designed for a freshman second-semester course for nomajors in qualitative organic analysis using TLC, involving student analysis of an unknown mixture by TLC and then a sniff-and-guess analysis by comparison with numbered vials of various compounds.