Anal. Chem., 59, 2045-2050 (1987). Investigation of the performance of several mathematical approaches for quantification of components in case of severe chromatographic and spectroscopic overlap. Demonstration by the separation of two amino acids, glycine and glutamine on silica with 1-butanol - acetone - acetic acid - water 7:7:2:4 followed by derivatization with O-phthaldialdehyde. Studies of 5 approaches based on factor analysis and Kalman filtering methods with errors of 5.9% for glycine and - 6.4% for glutamine.

J. Planar Chromatogr. 2, 49-52 (1989). Luminiscence polarization of chromatographic spots of 23 DNS amino acids using a two channel scanning laser fluorometric detector. TLC of DNS amino acids on polyamide with 1.5% formic acid in water.

J. Liquid Chromatogr. 13, 2829-2839 (1990). Description of a field portable TLC scanner based on digital image processing hardware, consisting of a CCD imaging hardware to capture and process video images. Use of a laptop computer with a software for subtraction of noise, correction of variations, automated lane finding, calibration, peak finding and integration.

Anal. Sci. 9, 309-310 (1993). Investigation of the two-photon ionization detection for photo-absorbing molecules on TLC plates using a third harmonic laser, providing high spatial resolution. Discussion of the use of the mesh electrode for the photoionization detection of photo-absorbing molecules on other nonelectroconductive materials such as paper and glass.

Anal. Chem. 68, 3885-3891 (1996). Investigation of the use of a scientifically operated charge-coupled device (CCD) for the detection and quantification of aflatoxins on a HPTLC plate. Use of a nebulizer-based sample application system to transfer the sample quantitatively onto the plate. Accomplishment of fluorescence excitation of the aflatoxins with a transilluminator, which caused the analytes to emit in the blue-green portion of the visible spectrum. Evaluation of the dynamic range, sensitivity, accuracy and precision of the system. Detection limits in the low picogram range.

J. Planar Chromatogr. 14, 109-112 (2001). A computer-driven office scanner has been modified to enable measurement of the fluorescence of aflatoxins on TLC plates. The main modifications were substitution of the light tube with a black light tube and inclusion of a filter. The modified scanner can be used to determine aflatoxins at low nanogram levels which, when used in combination with the appropriate TLC method, enables monitoring of the compounds in food and feed at the levels stipulated in European legislation.

CBS 96, 11-13 (2006). HPTLC of isopropylthioxanthone (ITX) in food, on silica gel in horizontal developing chamber with toluene - n-hexane 4:1 over 50 mm. Quantitative determination by fluorescence measurement at UV 254/>400 nm. Polynomial calibration via peak height, working range was 20 - 200 µg/kg. LOD is 64 pg (n=3) and in spiked fatty matrix 1 µg/kg. Positive findings were confirmed by ESI-MS in selective ion monitoring mode at m/z 255 and 277 using a plunger-based extraction device. Further confirmation by DART directly coupled to TOF-MS.

J. Planar Chromatogr. 27, 29-32 (2014). HPTLC of rhein in the pulp of Cassia fistula on silica gel with ethyl acetate - methanol - water 100:17:10. Quantitative determination (1) by TLC image analysis using a flatbet scanner and (2) by absorbance measurement at 435 nm. The hRF value for rhein was 49. Linearity was in the range of 400-1200 ng/zone for (1) and 29-230 ng/zone for (2). The intermediate/interday/intra-day precisions were below 3 % (n=3). The LOD and LOQ for rhein were 85 and 257 ng/zone for (1) and 3 and 11 ng/zone for (2). Mean recovery was 102.3 % for (1) and 101.2 % for (2).