J. Agric. Food Chem. 31, 420-423 (1983). TLC of gonyautoxin 2, gonyautoxin 3 on silica with tert. butanol - acetic acid - water 2:1:1. Detection by UV 365 nm after spraying with 1 % H2SO4 and heating at 110 °C for 5 minutes.

(Determination of alternaria toxins in fruit and vegetable products.) Z. Lebensm. Unters. Forschung 177, 447-453 (1983).TLC of alternariol, alternariolmonomethylether, altenuene, altertoxin I on silica with a) chloroform - methanol - acetic acid 91:8:1, b) ethyl acetate - acetic acid 85:15 (two-times development). Detection by UV 366 and 254 nm. Detection limit 30 ng.

J. Planar Chromatogr. 4, 194-198 (1991). Study of the retention behavior of different penicillin and cephalosporin derivatives on silica impregnated with tricaprylmethylammonium chloride (TCMA) by OPLC with eluents containing water and methanol. The basis of retention is hydrophobic interaction, controlled by the surface concentration of TCMA; main advantage: retention is independent of the pH of the eluent.

CBS 98, 5-7 (2007). HPTLC of gatifloxacin on silica gel in a saturated twin-trough chamber with n-propanol - methanol - ammonia 25% 50:10:9 over 80 mm. Quantitative determination by absorbance measurement at 292 nm. The hRf value of gatifloxacin was 60 and selectivity regardnig matrix was given. Linearity was between 400 and 1200 ng/band. The intraday and interday precision both were below 0.03 %. The limit of detection and quantification was 2.7 and 8.3 ng/zone, respectively. Recovery was between 99.2 and 101.9 %. The HPTLC method was suited to study gatifloxacin stability under different stress conditions according to ICH guidelines (acid, base, heat, oxidation, photostability).

Chinese J. Pharm. Anal. 26 (2), 221-224 (2006). HPTLC of gentamycin and related compounds on silica gel with chloroform – methanol – 25 % ammonia 5:7:6. The main compound is well separated from the impurities. Quantification by densitometry at 485 nm. Linearity was between 4.0 – 40 ng/spot (r2 = 0.99) and the limit of detection was at the low ng level.

Kinetic evaluation of the degradation process and identification of photoproducts by mass spectrometry. J. Liq. Chromatogr. Relat. Technol. 36, 2431-2445 (2013). HPTLC of difloxacin and its degradation products on silica gel with methylene chloride - methanol - 2-propanol - ammonia 25 % 4:4:5:2. Quantitative determination by absorbance measurement at 294 nm. The hRf values of difloxacin and its degradation products were 43, 25, 32, 39, respectively. Linearity was 1.2-2.4 µg/zone. LOD and LOQ were 0.01 and 0.03 µg/zone, respectively. Intermediate precision was below 2.0 %. Recovery (by standard addition) was in the range of 101.1-110.9 %.

J. Planar Chromatogr. 27, 124-131 (2014). HPTLC of sparfloxacin (1) and flurbiprofen (2) on silica gel with chloroform - methanol - formic acid 7:1:1. Quantitative determination by absorbance measurement at 258 nm. The hRF values for (1) and (2) were 45 and 75. Linearity was in the range of 100-600 ng/zone for (1) and 40-800 ng/zone for (2). The intermediate/interday/intra-day precisions were below 2 % (n=6). The LOD and LOQ were 30 and 90 ng/zone for (1) and 13 and 40 ng/zone for (2), respectively. Recovery (by standard addition) was in the range of 99.3-99.9 % for (1) and 101.1-101.3 % for (2).

J. Planar Chromatogr. 29, 273-280 (2016). HPTLC of piroxicam, tenoxicam, meloxicam and isoxicam on silica gel with ethyl acetate – toluene – butylamine 2:2:1. Detection under UV 290 nm. The method was applied to study the effect of oxidizing or reducing agents on the stability of these drugs.