Proc. Intern. Symp. on Planar Separations, Planar Chromatography 2001, pp. 173-179. Bioautography of cefazolin on silica gel TLC and HPTLC plates (without development) by dipping the plates into bacteria suspension or on the plate. Visualization of the antimicrobial activity by use of MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide). The method was considered as suitable for determination of the viability (capable of living) of given test bacteria on the TLC plate.

J. Planar Chromatogr. 18, 415-418 (2005). TLC of macrolide antibiotics (roxithromycin, midecamycin, erythromycin, azithromycin, and erythromycin ethylsuccinate) on cellulose with aqueous ammonium sulfate solutions concentrated from 0.5 to 4.0 M. Detection by exposure to iodine vapor.

J. Liq. Chromatogr. Relat. Technol. 31, 1903-1912 (2008). TLC of cefacetril on silica gel with methanol - acetonitrile in a sandwich chamber. The developed TLC plates were dried, then immersed briefly in the microorganism solution, and incubated for 20 h at 37 °C. After incubation the plates were sprayed with 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide solution and left at room temperature for 30 min. White inhibition zones were observed against a purple background (Chrom Biodip Antibiotic Test kit). The described procedure is suitable for screening and semiquantitative determination of antibiotic residues in milk.

J. Planar Chromatogr. 24, 524-528 (2011). TLC of cefixime on silica gel with toluene - ethyl acetate - formic acid - water 5:29:11:5 with chamber saturation for 30 min at 25 +/- 2 °C. The hRf value was 54. Quantitative determination by densitometry in absorbance mode at 293 nm. Linearity was between 500 and 1500 ng. The repeatability (%RSD) was below 2 %. The limit of detection and the limit of quantification was 9 and 42 ng/zone, respectively. The recovery was between 98.9-100.3 %.

J. Liq. Chromatogr. Relat. Technol. 37, 2420-2432 (2014). HPTLC of lamivudine (1) and zidovudine (2) on silica gel with ethyl acetate – hexane – methanol – acetic acid 40:40:20:1. Quantitative determination by absorbance measurement at 278 nm. The hRF values for (1) and (2) were 25 and 73, respectively. Linearity was in the range of 100-600 ng/zone for (1) and 200-1200 ng/zone for (2). The intermediate/interday/intra-day precisions were below 2 % (n=3). The LODs and LOQs were 5 and 15 ng/zone for (1) and 10 and 32 ng/zone for (2), respectively. Recovery was between 95 and 105 %.

J. AOAC Int. 98, 871-875 (2015). TLC direct bioautography of 18 thyme (Thymus) specimens and species on silica gel with methanol - water 27:73. Bioautography by dipping into a suspension of Bacillus subtilis for 8 s, followed by incubation for 17 h at 37 °C. The plates were sprayed with 0.2 % aqueous solution of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and incubated for 30 min at 37 °C. Thymus citriodorus and Thymus marschallianus were selected as promising targets for further investigations.

tincture using thin-layer chromatography–direct bioautography and liquid chromatography–tandem mass spectrometry techniques. J. Planar Chromatogr. 30, 131-135 (2017). HPTLC direct bioautography of eriodictyol (1) and 4,4՛-dihydroxy-_x000D_
5,5՛-diisopropyl-2,2՛-dimethyl-3,6-bifenylodion (2) in Thymus vulgaris on silica gel with chloroform – diethyl ether – methanol 30:10:1. Detection by spraying with anisaldehyde sulfuric acid reagent, followed by heating at 100 °C for 5 min. Direct bioautography by dipping into cell suspensions of the following bacterial strains: Microccocus luteus, Bacillus subtilis, Staphylococcus aureus, methicillin-resistant Staphyloccocus aureus, Staphyloccocus epidermidis (Se), luminescence gene-tagged Pseudomonas syringae and naturally luminescent marine bacterium Aliivibrio fischeri. Bioactive components (1) and (2) were further identified by liquid chromatography‒tandem mass spectrometry.

VII. Comparison of analytical methods for determination of impurities in tetracycline pharmaceutical preparations. J. Chromatogr. 314, 303-311 (1984). HPTLC of various tetracyclines on silica with acetone - 5 % aq. sol. of Na2 EDTA 10:1 and RP-TLC on C18-plates with methanol - acetonitrile - 0.5 M oxalic acid (aq. pH 2.0) 1:1:4 or 1:1:2. Detection by UV 366 nm or with 0.5 % Fast Violet B aq. solution and pyridine. Quantification by scanning at the dual-wavelength mode at 366/600 nm for 4-epitetracycline and chlortetracycline and at 425/650 nm for anhydrotetracycline and 4-epianhydrotetracycline. RP-TLC-densitometry appears to be a precise method for the determination of tetracyclines.