J. Chromatogr. A 1534, 179-187 (2018). Investigation of the influence of pH of the mobile phase buffer on retention of peptides in both normal phase (NP) and reversed phase (RP) HPTLC systems with C18 silica-based adsorbent as the solid phase. Comparison of the influence of pH on retention and/or migration distance of peptides in separation systems of HPTLC and pressurized planar electrochromatography (PPEC) techniques. It was found that the change of pH of the mobile phase buffer can be used for two-dimensional HPTLC separation of peptides, but much stronger change of separation selectivity can be achieved by overall inversion of separation system type (NP/RP). Influence of the mobile phase pH on selectivity of peptide separation in PPEC is different than that in HPTLC, due to the significant share of electrophoretic effect in mechanism of separation and better selectivity of separation by PPEC, however the change of pH affects the efficiency of the separation system in both techniques, so it can be used for optimization of separation conditions. Discussion of some modifications of PPEC equipment and materials useful for application of this technique in the field of peptide analysis.

An improved synthesis of pentagastrin (Acignost). Pharmazie 43, 10-12 (1988). TLC of the pentapeptide boc-ß-ala-trp-met-asp- phe on silica with chloroform - methanol - acetic acid 18:2:1, sec. butanol - 3% NH3 25:11 and 75:25, ethyl acetate - acetic acid - water 20:6:11, ether - acetic acid - water 77:15.4:7.6 and n-butanol - acetic acid - water 40:10:50 (upper phase). Detection of the peptide derivatives with ninhydrin-, chlor/TDM-, Ehrlich’s- and fluorescamine reagent.

J. of Medicinal Chemistry 32, 638-643 (1989). TLC of peptides on silica with butanol - acetone - water - pyridine 15:3:10:12 or 30:6:30:24 or 60:20:6:11 and butanol - acetone- water 5:2:3. Visualization by UV 245 nm, ninhydrin, Pauly’s reagent and iodine.

Antitumor evaluation of cyclic peptides and macrolides from Lissoclinum patella. J. of Natural Products 52, 732-739 (1989). TLC of cystine, threonine and thiazole amino acids on cellulose with butanol - water - acetone 4:1:1. Identification by 1H NMR and eims.

J. Planar Chromatogr. 8, 69-72 (1995). TLC and HPTLC of hepatotoxins in aqueous and algal samples on silica and RP-18 with 13 different mobile phase systems. Scanning densitometry at 196 nm, confirmation by multiwavelength scanning. The method described is a rapid and facile test, which can be performed in small laboratories, for screening water sources or blooms for cyanobacterial toxins in a hygienic setting.

J. Planar Chromatogr. 25, 571-574 (2012). HPTLC of theanine in tea extracts on silica gel with n-butanol - acetone - acetic acid - water 7:7:2:4. Detection by dipping into a ninhydrin reagent for 3 s, followed by heating at 105 °C for 5-15 min. Quantitative determination by analysis of green channels of photographs using the CP Atlas 2.0 software. The hRf of theanine was 35. Linearity was in the range of 1.4-14 ng/zone. The intermediate/inter-day/intra-day precision was below 0.7 % (n=3). Recovery (by standard addition) was between 95.7 and 102.5 %.

Helv. Chim. Acta 66, 1101-1109 (1983). TLC of peptidic conjugates carrying a single 2-carboxy-4, 6-dinitro-phenyl haptenic group and a carbohydrate moiety on silica with a) 1, 4-dioxane -water 5:1, b) propanol -water - ethyl acetate 7:2:1 and c) butanol - water - ethyl acetate 9:4:5. Detection with fluram and ninhydrin for peptides and amino acids and with sodium periodate/benzidine for the carbohydrate derivatives. Also electrophoresis.

J. Liquid Chromatogr. 6, 127-137 (1983). TLC of gamma -aminobutyric acid and glutamic acid on ionex SP-Ac (equilibrated with 0.05 % acetic acid) with ethyl acetate - water 8:92. Detection with 0.2 % ninhydrin in butanol- acetic acid 95:5 and heating at 70 °C.