J. Chinese Herb Med. (Zhongcaoyao) 23, 66-67 (1992). TLC of extract of Chinese Gan Fu Shu oral liquid on silica with chloroform – methanol – ethyl acetate 8:2:1. Detection by spraying with 10 % sulfuric acid and heating at 100°C for 5 min. Identification by co-chromatography with the standard.

J. Planar Chromatogr. 6, 21-28 (1993). Description of on-line coupling of HPLC, solid phase extraction (OSP), and TLC. The technique opens up new possibilities in the field of multidimensional chromatography of complex samples. Using the OSP-2 apparatus the HPLC eluent is exchanged by the inclusion of an on-line solid phase extraction step between the two chromatographic processes. This on-line coupling has been used for the quantitative determination of 4(5)-methylimidazole in caramel.

Talanta 41, 367-369 (1994). Dichlorvos in the presence of moisture breaks down to dichloroacetaldehyde which in turn reacts with phenylhydrazine hydrochloride to give a yellowish red color. In acidic media the color is intensified and the detection sensitivity increases. The reagent is selective for dichlorvos. Investigation of the interference with other insecticides, etc.

Indian J. Pharm. Sci. 66 (3), 306-308 (2004). HPTLC on silica gel with n-butanol - methanol - 6 M ammonia 5:1:2. Gatifloxacin showed Rf values of 0.47 ± 0.03. Quantitative determination by absorbance measurement at 292 nm. The method was validated in terms of linearity (400-1200 ng/spot), precision (intra-day variation 1.3 to 3.2 %, inter-day variation 3.9 to 5.0 %), accuracy (93.3 to 99.4 %), and specificity. The limit of detection and limit of quantification for gatifloxacin were found to be 10 ng/spot and 50 ng/spot respectively. The method is simple, sensitive, precise, and can be used for the routine quality control testing of marketed tablet formulations (400 mg).

IPC 56th 2004, Abstract No. GP-5. Simultaneous HPTLC determination of amlodipine and atenolol on silica gel with ethyl acetate - methanol - ammonia 60:40:3. Quantitative determination by scanning at 254 nm. The method was found linear in the range of 0.5 – 5.0 mg/mL amlodipine and 5.0 mg – 50 mg/mL atenolol. Recovery was 98.11 – 101.5 % for both of the compounds. The method was validated for accuracy, precision, linearity, specificity, LOD, and LOQ.

J. Chromatogr. A 1077 (2), 188-194 (2005). HPTLC of (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), procyanidin B1, and procyanidin B2 on cellulose prewashed with water (not necessary, when water was used as developing solvent) and dried with a hair dryer, with 1) water; 2) 1-propanol - water 1:4; 3) 1-propanol - water - acetic acid 4:2:1; 4) 1-propanol - water - acetic acid 2:8:1 in horizontal developing chamber (sandwich configuration). Detection with vanillin - H3PO4 reagent. Water enabled the separation of epimers C from EC and GC from EGC, as well as the dimers procyanidin B1 and B2. Additionally C, EGC, B1 and B2 were separated from all the other compounds. The best separation of the five main catechins (EC, GC, EGC, ECg, EGCg) present in green tea extract was achieved using 1-propanol - water - acetic acid 2:8:1. The chromatograms of oak bark extract developed in solvents with higher water content (1-propanol - water 1:4 and 1-propanol - water - acetic acid 2:8:1) showed less bands than chromatograms developed in solvents with higher organic modifier content (e.g. 1-propanol - water - acetic acid 4:2:1). It was proved that such behavior was due to the presence of procyanidins beside the main component catechin.

Ind. J. Pharm. Sci. 68 (6), 838-840 (2006). HPTLC of ofloxacin and ornidazole in tablet dosage form on silica gel with n-butanol - ethanol - ammonia 5:5:4. Quantitative determination by absorbance measurement at 295 nm. The method was found to be linear in the concentrate range of 1-5 ng/spot with recovery of 99.5-102.5 % for both compounds. The method was validated for linearity, accuracy, precision, repeatability, and specificity.

J. Chromatogr. A 1046 (2), 251-257 (2007). Fluorescence scanning densitometry of various analytes on HPTLC silica gel plates impregnated with a solution of coralyne cation, based on the increase or decrease, that the corresponding analyte induces on native coralyne emission at a given excitation wavelength. Compared to a procedure previously described for berberine cation, and Reichardt's dye probes, the sensitivity of coralyne in HPTLC detection of non-fluorescent, structurally different analytes (e.g. long-chain alkanes, alcohols, alkylbromides, neutral lipids) is superior.