Influence of sample preparation methods and conditions. J. Liq. Chrom. & Rel. Technol. 27, 2463-2470 (2004). TLC of 1-(3,4-methylenedioxyphenyl)-2-nitropropene, an intermediate product of MDMA (3,4-(methylenedioxy)methamphetamine, also known as ,ecstasy’, and impurities on silica gel in a horizontal chamber with chloroform - ethyl acetate 49:1. Detection of separated impurities under UV light at 254 and 366 nm.

J. Planar Chromatogr. 20, 287-292 (2007). TLC of mancozeb, NaDDC, propineb, ziram, and zineb on cellulose or cellulose impregnated with heavy metal salts with mobile phases prepared from water, n-butyl acetate, isopropanol, and lauryl sulfate. Visualization with iodine vapor. Plates were also coated with cereal flour, and with mixtures of cellulose and cereal flour.

Anal. Chem. 80, 6821-6823 (2008). HPTLC of Cr3+ and Cr 6+ on silica gel in a saturated chamber with distilled deionized water and Triton-X-100 in concentrations between 0.001 and 0.1%, which is around the critical micelle concentration. Separation was achieved in seconds over 1 cm. Laser ablation was used to volatilize the chromium species directly from the chromatographic material prior to ICP-MS detection. The reliability of calibration was satisfying with precisions between 3 - 30 % and detection limits in the low ng-range. Silicium, which is present in the silica gel plate, was discussed as suitable internal standard.

Phytochem. Anal. 21, 463-469 (2010). HPTLC of pyrocatechol in the barks of different species and clones from the genus Salix on diol phase by mutiple gradient development with chloroform - hexane 7:3 - ethyl acetate - formic acid in the following gradients: (I) 18:2:0.01, (II) 17:3, and (III) 16:4. Detection by spraying with thymol reagent. Quantitative determination by absorbance measurement at 254 nm.The hRF of pyrocatechol was 25. Detection and quantification limits were 30 and 100 µg/mL, respectively. The intra-day and inter-day precisions had a %RSD lower than 2.5 %. Recovery (by standard addition) was 96.3 %. The correlation coefficient of pyrocatechol concentrations determined by HPTLC and HPLC was 0.9932.

Volumes 1-3, CBS Publishers & Distributors, New Delhi, India (2013). The first volume provides a comprehensive introduction to the HPTLC technique, including details for each HPTLC step as well as various factors which influence the performance of a HPTLC analysis. Then presented over 3 volumes, 528 protocols for the HPTLC analysis of pharmaceutical formulations follow. Each protocol provides details on the preparation of samples and standards, chromatographic equipment, parameters for densitometric evaluation, chromatographic conditions, including stationary phase, mobile phase, standard and sample application, chamber saturation, relative humidity, quantity of mobile phase, temperature, migration distance and other critical parameters. References to the original publication are given as well as comments on the validation or any comparative study. Each protocol is illustrated with a typical densitogram, structures of the compounds analysed and overlaid UV spectra of compounds analysed (for selection of suitable wavelength for densitrometric scanning). All in all a comprehensive collection of protocols for pharmaceutical formulations.

Braz. J. Microbiol. 44, 401-406 (2013). HPTLC of trichothecene in multiplex PCR isolates of Fusarium culmorum on silica gel with chloroform - methanol - water 45:5:1. Detection by dipping into 10 % aluminium chloride in methanol-water mixture, followed by heating at 110 ºC for 20 min. Qualitative determination at UV 366 nm._x000D_

J. Liq. Chromatogr. Relat. Technol. 40, 320-326 (2017). HPTLC of 31 substances of toxicological interest on RP-18 with 60 % acetonitrile in buffer pH 6.0, on silica gel with chloroform – methanol 9:1 and using pressurized planar electrochromatography (PPEC) on RP-18 with 60 % acetonitrile in buffer pH 2.2. The authors showed the application of the migration distance of the solutes, obtained by the PPEC technique, with a proposed equation allowed for increase of likely identification of substances in toxicological analysis.

Lipids 18, 896-899 (1983). Two-dimensional separation of phospholipids on silica with 1) chloroform - methanol - NH3 65:25:5., 2) chloroform - acetone - methanol - acetic acid - water 10:4:2:3:1; visualizing under UV after spraying with 2',7'-dlchlorofluoresceine; removing the fractions by scraping and identification by co-chromatography with authentic standards (one-dimensionally); plasmalogenes can be identified by exposing the plate to HCl (after the first development).