J. Planar Chromatogr. 2, 65-70 (1989). For qualitative analysis monodansyl cadaverine (MDC) was employed without further purification. Column-chromatographic purification is recommended for the quantification of short chain carboxylic acids. For in situ derivatization the carboxylic acid sample solutions were applied to the HPTLC plates as bands with a maximum length of 10 mm. These were then „overlayed“ with MDC solution containing N,N’-dicyclohexylcarbodiimide to activate the acids. Short-chain carboxylic acids were separated on normal silicagel phases with toluene - ethyl acetate - ammonia mixtures as mobile phase. Stepwise and gradient developments allow the baseline separation. Long-chain carboxylic acids are better separated on RP-18 phases with acetonitrile-tetrahydrofuran mixtures and methanol as mobile phase.

J. Planar Chromatogr. 4, 360-364 (1991). Description of a multidimensional approach to the coupling of HPTLC with capillary GC for the separation of the components of Matricaria chamomila. Multiple development on silica gel plates using solvents of different polarity and selectivity enables the separation of the components into various chromatographic zones, differing in the polarity of their constituents.

Chinese J. Pharm. Anal. (Yaowu Fenxi Zazhi) 16, 154-157 (1996). TLC on silica with a) petrol ether - hexane - ethyl acetate - ethanol 2:8:5:2, b) petrol ether (60 - 90 °) - hexane - ethyl acetate - ethanol - NH3 2:4:10:10:1. Detection by spraying with potassium iodobismuthate reagent. Quantification by HPLC after elution.

II. Calibration methods concerning quantitative hydrocarbon-group type analysis. J. Chromatogr. Sci. 36, 487-494 (1998). Use of TLC-FID for the hydrocarbon group type analysis of fossil fuels using internal normalization method. Investigation of repeatability, linear intervals and sample load ranges for quantitation towards different products covering a broad range of boiling points and chemical fractionalities in the field of fossil fuels. Comparison of the results with those obtained using external standard calibration. Validation of the method with TLC-UV scanning.

Chinese J. Pharm. Anal. (Yaowu Fenxi Zazhi) 22 (1), 47-50 (2002). TLC on silica gel with 1) toluene - ethyl acetate - formic acid 5:4:1, 2) petroleum ether (30-60°C) - ethyl acetate 50:1. Detection 1) by spraying with NH3 - AgNO3 reagent, 2) under UV 254 nm. Identification by finger print technique.

J. Chinese Trad. Patent Med. (Zhongchengyao) 10, 858-860 (2004). TLC on silica gel with 1) chloroform - methanol - water 13:7:2, 2) isopropanol - ethyl acetate - water 17:9:9, n-butanol - formic acid - water 15:3:2. Detection 1) by spraying with 10 % H2SO4 in ethanol and heating at 110 ºC, 2) by spraying with 0.3 % ninhydrin in n-butanol, 3) by spraying with 10 % vanillin solution. Identification by fingerprint techniques. Quantitative determination of ginsenoside by HPLC.

Anal. Chem. 75, 118-125 (2003). Online TLC separation and electrospray mass spectrometry (TLC/ESI-MS) by direct linking of a commercial overpressure TLC instrument, OPLC 50, and a Q-TOF mass spectrometer. Separation on silica gel with dichlormethane - methanol - water 60:35:8. A sensitivity of 5 pmol of glycosphingolipid was readily demonstrated for TLC/ESI-MS and 20 pmol for TLC/ESI-MS/MS production scanning to derive the saccharide sequence and long chain base/fatty acid composition of the ceramide. Initial preconditioning of TLC plates is necessary to achieve high sensitivity detection by reducing chemical background noise. Plates can be used repeatedly (at least 10 times) for analysis, although this may result in a minor reduction in TLC resolution. Following solvent development, separated components on the TLC plates can be detected in the conventional way by nondestructive staining or UV absorption or fluorescence and can be stored for on-line TLC/ESI-MS analysis at a later stage without reduction in mass spectrometric detection sensitivity and chromatographic resolution. Aspects for further improvement of OPLC instrumentation include use of narrower TLC plate dimensions and refined design of the eluate exit system.

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.