Phytochem. Anal. 20, 154-158 (2009). TLC of the purgative constituents of rhubarb (sennoside A and sennoside B) on silica gel with 1-propanol - ethyl acetate - water - acetic acid 40:40:30:1. After drying detection by spraying with 10 % sulfuric acid and heating. For the eastern blotting assay the developed TLC plate was dried and sprayed with isopropanol - methanol - water 1:4:16. Transfer by using a PVDF membrane sheet for further treatment.

J. Chromatogr. A 1577, 101-108 (2018). In order to overcome the difficulty of the interpretation of the MS signals present at a low intensity for unknown degradation products or impurities, a new strategy and open-source software called eicCluster was developed. It offered unsupervised machine learning algorithms and powerful interactive visualization tools that made data processing fast and intuitive. The low-intensity HPTLC-HRMS signals were highlighted in a stressed formulation by using eicCluster. Thus, even compound ions present at low intensities were separated in subclusters from background signals (in silico highlighting). The respective preprocessing led to intensity-agnostic signals and the t-SNE algorithm clustered mass signals based on their similarity. The resulting 2D maps allowed a new view on the data set to such low-intensity target molecules in complex mixtures. Moreover, the targeted on-surface synthesis of degradation products (in situ highlighting) was shown to support a fast structure elucidation, when standards are not commercially available. It allowed a better understanding of the proposed degradation reactions in the formulation. Comparison with the results of stressed samples as well as the proposed degradation products of on-surface synthesis proved that in silico and in situ signal highlighting substantially eased structure elucidation and data processing.

Chinese J. Chem. 4, 35-36 (1987) (Huaxue Tongbao). Use of N,N-dimethyl-a-naphthylamine-5-sulfonyl chloride as a pre-chromatography derivatizing agent for some pesticides and herbicides. Spraying with tris(2-hydroxyethyl)-amine or paraffin oil after development. Detection by fluorodensitometry at 320 nm excitation and 500 nm emission.

An overview. Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 71-79 (1991). Overview of a new postchromatographic derivatization method; special devices for contact reagent transfer were described.

J. Chromatogr. 669, 275-276 (1994). Discussion of the extension of the title compound to five-membered heteroaromatic rings containing 1-4 nitrogen atoms, as a selective chromogenic reagent. 22 compounds were examined. Discussion also of the reaction mechanisms.

Helv. Chim. Acta 80, 1144-1152 (1997). TLC of monoterpene glycosides on silica with butanol - propanol - water 2:1:3. Detection under UV 254 and 365 nm or with Godin reagent. TLC autographic assay for the detection of free radical scavenging properties by spraying with a 0.2% solution of DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) in methanol. After 30 min, active compounds appear as yellow spots against a purple background.

1. The gram-positive test bacterium Bacillus subtilis. J. Planar Chromatogr. 15, 132-137 (2002). Study to determine optimum conditions for culture of a test microbe Bacillus subtilis enabling the authors to establish its use for direct bioautography. It was found that a '5-9-h' broth culture of B. subtilis was suitable. A much shorter incubation time (4-8 h) was sufficient for TLC plates instead of the original 18 h in a previous study. One additional advantage is the possibility to use TLC plates coated with sorbents other than silica gel. TLC of cefazolin on silica gel, aluminium oxide, cellulose, and polyamide.

Optimization of several image-denoising techniques. Acta Chromatographica 21(3), 355-367 (2009). Different techiques for videoscan denoising are presented. Due to the charged-coupled devices (CCD) noise can be a serious problem during videoscanning, especially when scanning dark plates with weakly fluorescent spots. Optimization of several kind of filters (averaging, circular, Gaussian, Savitzky-Golay, median, Wiener, FIR) and wavelet shrinkage (twelve mother wavelets from the Daubechies, Symmlet, and Coiflet family, five decomposition levels, and soft/hard thresholding) against noise autocorrelation or mean-squared error to the reference image obtained by grabbing and averaging 256 CCD frames. The median filter provided the best results. The other filters except Gaussian and wavelet shrinkage at high decomposition level were also sufficient. The Gaussian filter and wavelet shrinkage at low decomposition level could not be recommended.