Frontiers in Marine Science 7, 266 (2020). Methanol extracts from marine sponge Haliclona cnidata (Chalinidae) submitted to different stresses (antibiotics and/or darkness) were separated on HPTLC silica gel with an automated 15-step gradient based on methanol, dichloromethane and n-hexane. Bioluminescence was recorded after immersing the HPTLC plates into Aliivibrio fischeri suspension. Antibacterial activity and quorum sensing enhancement were analysed on software, and Pearson’s similarity coefficient was applied to generate similarity matrices for cluster analysis (UPGMA, Unweighted Pair Group Method with Arithmetic Mean). Only slight differences were observed, especially in QS enhanced zones in stressed vs. control cultures.

Nature - Sci. Rep. 11, 62 (2021). Samples were isopropylacetate – methanol 3:2 fractions of (1) n-hexane extracts of larvae of Apis mellifica carnica (Apidae) from hives exposed to different concentrations of neonicotinoid pesticide clothianidin in their food, as well as (2) worker jelly adsorbed from brood combs of the same hives on adsorptive filter strips (unused filter strip parts were kept as background control). HPTLC on silica gel with chloroform – methanol – water – ammonia 30:17:2:1 for (1), and with an 8-step gradient based on methanol, chloroform, toluene, and n-hexane for (2, see CBS 105: Optimization of an AMD 2 method for determination of stratum corneum lipids). Visualization at UV 366 nm before and after derivatization by immersion into primuline reagent (primuline 0.5 g/L in acetone – water 4:1). Furthermore, antibacterial activity of (2) was assessed by recording the bioluminescence on the HPTLC plates, neutralized after elution and immersed into Aliivibrio fischeri suspension. Semi-quantitative comparison showed that a higher exposure to clothianidin was correlated with a decrease in lipid composition as well as in antibacterial activity.

CBS 100, 2-5 (2008). HPTLC of photodegraded UV filters and sunscreen on silica gel LiChrospher prewashed with methanol. AMD 2 development of UV filter standards photodegradation products with diisopropylether - n-hexane in 6 steps over 50 mm without preconditioning, and of sunscreen samples photodegradation products with t-butylmethylether - n-hexane in 7 steps over 50 mm with preconditioning, followed by drying at 120 °C for 30 min. Detection at 254 and 366 nm, followed by biodetection via dipping the plate in a Vibrio fischeri solution for 1 s and evaluation with the Bioluminizer (exposure time 55 s). Densitometric evaluation by multi-wavelength scan at 200-400 nm.

CBS 113, 13-15 (2014). HPTLC of glycosylceramide Glc-d18:2 h16:0 from wheat germ and standards squalene, cholesteryl oleate, glyceryl trioleate, linoleic acid, ß-sitosterol, and ß-sitosterol glucoside on silica gel in the AMD 2 with a 18-step gradient modified from Opitz et al. (Chromatographia 73 (2011) 559), methanol replaced ethanol, and the mobile phase composition was changed slightly (pre-conditioning with 4 M acetic acid before each step, drying time 1.5 min, development duration 3 h and solvent consumption 200 mL). Detection by dipping in copper sulfate phosphoric acid reagent for 20 s and heating at 130 °C for 15 min revealed grey-brown bands. Densitometry evaluation by absorbance measurement at 546 nm. For Glc-d18:2 h16:0, regression analysis showed a polynomial relationship with coefficients of determination (R2) from 0.995 to 0.999 (n=3, 50 - 1000 ng/band). LOD (S/N 3) and LOQ (S/N 10) of Glc-d18:2_x000D_ h16:0 were 10 ng/band and 50 ng/band, respectively (n = 6).

J. Planar Chromatogr. 4, 106-110 (1991). Presentation of 3 examples of optimization of AMD gradients: 1 + 2: Universal gradients optimized for the separation of phenolic compounds spanning a wide polarity range on diol layers, 3: Optimization for the separation of organochlorine pesticides on silica spanning a low polarity range. Preliminary isocratic developments of selected standards were performed with binary solvent mixtures in order to set up the gradients. The retention data (as plots of Rm values against solvent composition) can be used for the choice of the gradient components and gradient boundaries.

Chromatographia 37, 365-373 (1993). TLC of title compounds on silica by AMD using two different solvent gradients. Identification by in-situ measurement of the UV spectra. Determination by densitometry at 280 nm. Discussion of the advantages of this TLC method.

Teil 2: Die online Kopplung HPLC - AMD. (AMD (Automated Multiple Development); application and online coupling with reversed phase HPLC. Part 2: Online coupling HPLC-AMD). Dünnschicht-Chromatographie InCom Sonderband 1996, 53-71. Online coupling of HPLC and AMD is a two-dimensional separation system, where the completely different separation mechanisms of reversed-phase chromatography in a column and planar chromatography on silica are coupled. Online coupling of HPLC and AMD/HPTLC is capable of separating several thousand substances. With this system practical any number of pesticides in any kind of water sample can be quantified. Without clean-up, interferences of the matrix are reduced to nearly zero. The method is demonstrated by the analysis of a surface water sample spiked with pesticides.

CBS 84, 9 (2000) HPTLC of aflatoxins on silica gel with chloroform - acetone 9:1. Quantitative determination by fluorescence measurement at 366/>400 nm.