Food Chem. 110, 538-546 (2008). TLC of wax esters of oilfish (Ruvettus pretiosus) and escolar (Lepidocybium flavobrunneum) on silica gel with xylene. Detection by spraying with 40 % sulfuric acid in ethanol - anisaldehyde 9:1, followed by heating at 100 °C for 2 min or until color is observed. The hRf value of wax esters was 60. The method was compared with DNA sequencing and GC-MS. The TLC method is inexpensive, provides a reliable result within 30 min, and is suitable for screening of numerous samples.

J. Planar Chromatogr. 21, 107-112 (2008). Optimization and comparison of the acidic visualization methods most often used for steroids. OPLC of ethinyl estradiol, ’dienolether’ (3-methoxyestra-2,5(10)-dien-17b-ol), norethisterone, norethisterone acetate, norethisterone enanthate, nandrolone, and nandrolone decanoate on HPTLC silica gel with cyclohexanone - ethyl acetate - chloroform 1:1:1. Detection with sulfuric acid at three different concentrations, phosphomolybdic acid, and phosphoric acid with different heating temperatures for different times. Evaluation under UV 366 nm (sulfuric acid, phosphoric acid) and in white light (phosphomolybdic acid). It was found that derivatization at higher temperatures for shorter periods usually results in greater sensitivity, although heating for longer periods at lower temperatures leads to a more stable and robust result. Evaluation by videodensitometry.

J. Chromatogr. Sci. 46 (4), 304-307 (2008). HPTLC rabeprazole and domperidone in pure powder and in capsule formulations on silica gel aluminium layers with ethyl acetate - methanol - benzene - acetonitrile 3:2:3:2. Quantification by absorbance measurement at 287 nm. Linearity was between 400 and 1200 ng/spot for rabeprazole and 600 and 1800 ng/spot for domperidone. Recovery was 99.8 % for rabeprazole and 99.4 % for domperidone. This method is simple, precise, and sensitive, and it is suitable for the simultaneous determination of rabeprazole and domperidone.

Microbiol. Res. 163, 307-313 (2008). HPTLC of norharmane from cyanobacterial culture medium extracts on silica gel with ethyl acetate - methanol - water 200:33:27 or ethyl acetate - formic acid - water 20:2:1. The hRf values of norharmane were 65 and 20, respectively. Evaluation under UV 254 nm without further derivatization. The screening of microalgal culture medium was performed by HPTLC and HPLC.

J. Chromatogr. A 1207 (1-2), 155-159 (2008). HPTLC of secoisolariciresinol diglucoside in flaxseed on RP18W with methanol - 0.1 % formic acid 2:3, using the alkaline hydrolysis in aqueous medium of undefatted samples. Quantitative determination by absorbance measurement at 282 nm. Validation of the method following the protocol proposed by the Société Francaise des Sciences et Techniques Pharmaceutiques lead to a dependable and high throughput procedure well suited for routine application. Linearity was between 321–1071 ng/zone and the RSD of repeatability and intermediate precision did not exceed 3.6 %.

Microbiol. Res. 163, 624-632 (2008). TLC of FK506 and FK520 from the fermentation broths of Streptomyces species, on silica gel with isopropyl alcohol – benzene 3:17 or methylene chloride – acetone 2:1. Detection by bioautography with the A. IDR 721 test organism, and also by spraying the plate with cesium sulphate 1 % in sulfuric acid 10 % followed by heating at 120 °C. The hRf of the immunosupressant compounds were 50 or 60, depending on the developing solvent.

J. Liq. Chromatogr. Relat. Technol. 30, 2369-2383 (2007). TLC of 2-arylpropionic acids, namely ibuprofen and naproxen, on silica gel and silica gel impregnated with a 0.03 mol/L solution of L-arginine in methanol by dipping for 2 s, with ethanol and ethanol containing several drops of acetic acid. Quantitative determination by absorbance measurement at 254 nm. It was demonstrated that the crystalline chirality of the silica gel adsorbent is most probably responsible for the horizontal enantioseparation, whereas the molecular chirality of L-arginine deposited on the silica gel layer is responsible for the vertical enantioseparation.

J. Planar Chromatogr. 21, 367-371 (2008). HPTLC of harmane (1-methyl-9H-pyrido[3,4-b]indole) and Glu-P-1 (2-amino-6-methyldipyrido[1,2-a:3’,2’-d]imidazole) on silica gel (prewashed with methanol) in a flat-bottom chamber with diethyl ether - methanol 49:1 at a relative humidity of 42 % and a temperature of 26 °C. Before development, the activity and pH of the silica gel were adjusted in a saturated twin trough chamber with 20 % aqueous ammonia (25 %) for 15 min. Quantitative determination by fluorescence measurement at UV 366/>400 nm. HPTLC-MS coupling via an extractor-based interface using a circular and an oval plunger for extraction of the adjacent heterocyclic amines. The circular plunger was easier to position, however the oval plunger was shown to be optimal (more selective) for adjacent bands.