Chemistry of Plant Protection 12, 181-195 (1995). AMD as a TLC technique, which combines the wide range of polarity gradient elution on silica with a separation power similar to HPLC. Application to parallel analysis of 12 samples for some dozens of pesticides. Limit of quantification is 0.05 µg active ingredient per liter. First step allows screening for active ingredients, second step confirms positive results by gradient separation and comparison of UV spectra of sample and standard. Offline-coupling with MS. Standardization as DIN method 38407-part 11 for determination of pesticides in ground and drinking water.

J. Liq. Chrom. Rel. Technol. 27, 2057-2070 (2004). HPTLC of pioglitazone hydrochloride ((±)-5-[p-[2-(ethyl-2-pridinyl)ethoxy]-benzyl]-2,4-thiazolidinedione hydrochloride), rosiglitazone maleate ((±)-5-[4-[2-[N-methyl-N-(2--pyridinyl)amino]-ethoxy]benzyl]-2,4-thiazolidinedione maleate), and repaglinide S(+)-2-ethoxy-4-[N-[1-(2-piperidinophenyl)-3-methyl-1-butyl]-aminocarbonylmethyl]benzoic acid on cyano-phase with 1,4-dioxane - buffer pH 2.8/4.4/6.4/7.9 1:4; 2:3; 1:1; 3:2; 2:1 in horizontal chambers without saturation. Quantitative determination of pioglitazone by reflectance/transmittance measurement at 266 nm.

CBS 94, 2-4 (2005). HPTLC-AMD of four pharmaceuticals and extracts of surface water on silica gel prewashed with 2-propanol (immersion for 24 h) with a 25-step gradient based on acetonitrile - formic acid - dichloromethane. Luminographic detection at ng-level by immersion of the developed HPTLC plates into Vibrio fischeri bacteria suspension. Visual evaluation with CCD-camera, exposure time 40 s, inversion and scaling of exposure in pseudocolors. To remove matrix (humic acids) from surface water samples size exclusion chromatography is recommended.

J. Planar Chromatogr. 17, 375-378 (2004). HPTLC of parthenolide and extracts of feverfew capsules on silica gel with ethyl acetate - n-hexane 3:2 in glass chambers presaturated for 30 min. Detection by dipping in p-anisaldehyde reagent and heating at 105 °C for 5 min, followed by immediate densitometric scanning at 543 nm. The method is precise with CV < 5%; calibration recovery of 101.12 +/- 4.11 % and overall accuracy of 101.14 +/- 4.47 %. The levels of parthenolide in the products analyzed ranged from 0.03 to 0.24 %.

Chinese J. Trad. Pat. Med. (Zhongchengyao) 27(2), 158-161 (2005). HPTLC on silica gel with 1) cyclo-hexane - ethyl acetate - methanol 4:5:1; 2) n-hexane - ethyl acetate 3:1; 3) n-hexane - ethyl acetate 9:1; 4) cyclohexane - ethyl acetate - diethylamine 45:20:3. Detection 1) under UV 365 nm; 2) by spraying with 10 % H2SO4 in ethanol and heating; 3) by spraying with diluted potassium iodobismuthate solution followed by spraying with sodium nitrite solution in ethanol. Identification by fingerprint technique. Semi-quantitative determination of aconitine by comparison with the standard. Quantification of strychnine by HPLC. The results for some real life samples are given.

J. Chromatogr. A 1000 (1-2), 963-984 (2003). Identification of core technologies with the potential to influence the development of TLC over the next decade. Core technologies are identified as: (i) methods to provide a constant and optimum mobile phase velocity (forced flow and electroosmotically-driven flow), (ii) video densitometry for recording multidimensional chromatograms, (iii) in situ scanning mass spectrometry, and (iv) bioactivity monitoring for selective detection. In combination with two-dimensional, multiple development and coupled column-layer separation techniques these core technologies could dramatically increase the use of TLC for the characterization of complex mixtures. It is also demonstrated that TLC has strong potential as a surrogate chromatographic model for estimating biopartitioning properties. To convert these opportunities into practice the current state-of-the-art of the core technologies is described and the principle obstacles to progress identified.

Part IV. Separation on RP 18 plates with ternary mobile phases. J. Planar Chromatogr. 18, 228-233 (2005). HPTLC of heptanoic to eicosanoic acids on RP-18 (with and without concentrating zone). The best chromatographic conditions for separation of the fatty acids were RP-18 plates without concentrating zone and methanol - ethanol - water 9:9:2, and RP 18 plates with concentrating zone and methanol - ethanol - water or methanol -n-propanol - water 9:9:2. Detection by exposure to iodine vapour. Separation of acids from methanoic to butanoic and from tetracosanoic to triacontanoic acid was not possible.

J. Planar Chromatogr. 18, 151-154 (2005). HPTLC of imidacloprid, fenitrothion, and parathion on silica gel (prewashed with methanol and activated at 110 °C for 30 min) with hexane - acetone 7:3 in an unsaturated twin-trough chamber. Quantitative determination by absorbance measurement at 287 nm.