J. Planar Chromatogr. 22, 65-71 (2009). Presentation of two simple and rapid HPTLC methods for early detection of the effects of herbicides using two different groups of plant biomarkers, which were developed as field tests (Herbicide Weed Response test - HWR-Test). Phytochemical changes can be detected before any morphological changes are visible on the plants. These changes are defined as biomarkers and can be detected by HPTLC-screening. After overall identification of the phytochemical biomarker pattern, two different biomarker groups, carbohydrates and amino acids, were detected using modified reagents for color reactions. Evaluation under daylight and videodensitometric analysis of digital images by VideoScan software. The screening method was previously described [H. W. Ravn, M. Hjorth, L. Lauridsen, P. Kudsk, S. K. Mathiassen, L. Mondolot, Bull. Environ. Contam. Toxicol. 75, 236-245 (2005)].

Phytochem. Anal. 20, 177-190 (2009). TLC and HPTLC of polyphenols (tellimagrandins I and II, rugosins A, B, D and E and other) in commercially available products of meadowsweet (Filipendula ulmaria) and dog rose (Rosa canina) on silica gel, LiChrospher Si 60, RP-18 and amino phase with tetrahydrofuran - acetonitrile - water 3:1:1, of tannins on amino phase with acetone - formic acid 3:1, of flavonols with acetone - formic acid 17:3, of tannins with diisopropyl ether - acetone - formic acid - water 4:4:1:1, and of flavonols with diisopropyl ether - acetone - formic acid - water 5:3:1:1. Detection of polyphenolic compounds under UV light at 254 and 366 nm before and after spraying with natural products reagent followed by polyethylene glycol reagent. Detection in white light after spraying with 1 % iron(III) chloride (for tannins and phenolic acids), vanillin-hydrochloric acid (flavonols) or bis-diazotised sulfanilamide (for all polyphenols). Quantitative determination of polyphenol contents by HPLC with UV detection. Meadowsweet flowers and rose hips with seeds yielded 55.5-124.8 and 0.4-1.3 mg/g of ellagitannins, respectively. The sum of detected polyphenols was 83.9-165.7 mg/g for Filipendulae ulmariae flos and 1.2-2.7 mg/g for Rosae pseudo-fructus cum fructibus.

Anal. Chim. Acta, 576 (2), 253-260 (2006). Description of a simple, sensitive, selective, precise and stability indicating method for determination of gatifloxacin both as a bulk drug and from polymeric nanoparticles by TLC on silica gel with n-propanol - methanol - 25 % ammonia 50:10:9. The hRf value of gatifloxacin was 60. Separation from degradation products (produced under acidic and basic conditions and upon wet and dry heat treatment) was good. Quantitative determination by absorbance measurement at 292 nm. Linearity was 400 - 1200 ng/spot, with a correlation coefficient of 0.9953. The limit of detection and quantitation was 3 and 8 ng/spot, respectively.

J. Chinese Trad. Patent Med. 30 (11), 1635-1638 (2008). TLC of Sanjin Ganmao pill extracts on silica gel with 1) chloroform - methanol 17:3; 2) chloroform - methanol - formic acid 35:5:2; 3) chloroform - methanol - formic acid 90:10:1. Detection 1) by spraying with 10 % sulfuric acid in ethanol and heating; 2) by exposure to ammonia vapor. Identification by comparison with the standard hyperin and other standards of the component drugs.

Anal. Biochem. 360 (1), 130-137 (2007). Determination of cholesteryl ester hydroperoxides, especially cholesteryl linoleate hydroperoxide isomers, by combination of TLC blotting with diphenyl-1-pyrenylphosphine fluorescent detection (DPPP-TLC blotting) and GC-electron ionization-MS (GC-EI-MS). After DPPP-TLC blotting of cholesteryl ester hydroperoxides fluorescent zones were obtianed which were extracted and derivatized by hydrogenation, transmethylation, and trimethylsilylation. The resulting methyl ester/trimethylsilylether derivatives of hydroxyoctadecenoic acid were then analyzed by GC-EI-MS using selected ion monitoring of isomer-specific fragment ions originating from the alpha-cleavage of the trimethylsilyloxyl group.

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.

J. Chromatogr. Sci. 48 (1), 45-48 (2010). HPTLC of ambroxol hydrochloride on silica gel with methanol - triethylamine 2:3. The hRf value of ambroxol was 53. Quantification by absorbance measurement at 254 nm. Linearity was given in the range of 100-1000 ng/spot with r2 = 0.9966 (via peak area). The limits of detection and quantitation were 10 and 30 ng/spot, respectively. Ambroxol hydrochloride was susceptible to degradation under oxidation and thermal stress conditions. The method is suitable for purity testing of the drug as it detects the related impurities.

Chinese J. Hospit. Pharm. 29 (4), 336-338 (2009). TLC of astragaloside in Tianjian capsules on silica gel with chloroform - methanol - water 13:6:2. Detection by spraying with 5 % sulfuric acid in ethanol followed by heating at 105 ºC until coloration. Quantification by densitometry at 515 nm. The linearity was between 0.98 and 4.90 µg/spot (r2 = 0.998), the %RSD was 2.4 % (n = 6) within plate and 2.3 % (n = 6) inter-plate, standard addition recovery was 99.2 % with RSD = 1.7 % (n = 6).