Rapid Commun. Mass Spectrom. 24, 1721-1729 (2010). Ambient proximal probe thermal desorption (TD) sampling of substances from a HPTLC plate and coupled with secondary ionization by atmospheric pressure chemical ionization (APCI) or electrospray ionization (ESI). The method does not require a specialized ionization source. Different anaytical parameters and performance metrics are reported and the method covers a wide range of analyte types including explosives, dyestuffs, herbicides and pharmaceuticals.

Eurasian J. Anal. Chem 5(1), 95-103 (2010). An HPTLC method is reported for quantification of glycyrrhetinic acid and apigenin in Glycyrrhiza glabra. Methanolic and acidic-methanolic extracts are subjected to chromatographic separation on silica gel with ethyl acetate - ethanol - water - 25 % ammonia 63:20:4:1. The method was linear in the range of 160-960 ng/band for glycyrrhetinic acid and 32-96 ng/band for apigenin. Glycyrrhiza glabra was found to contain 0.65 % of glycyrrhetinic acid and 0.0004 % of apigenin.

Eurasian J. Anal. Chem. 5(1), 25-27 (2010). An HPTLC method is reported for estimation of levodopa in seeds of Mucuna pruriens and its herbal formulation. HPTLC on silica gel with n-butanol - glacial acetic acid - water 5:1:4. Densitometric evaluation at 280 nm. The hRf value of levodopa was 39. The method was linear in the range of 100-1000 ng/band. The method is suitable for estimation of levodopa in herbal formulation.

Rec. Nat. Prod. 3/4, 178-186 (2009). An HPTLC method has been reported for quantitative estimation of alpha-mangostin in fruit pericarp of Garcinia mangostana (Hypericaceae). HPTLC on silica gel with chloroform - methanol 9:1 in a saturated chamber (10 min). The plate was derivatized with anisaldehyde sulfuric acid reagent. Densitometric quantification at 382 nm. Alpha-mangostin was detected as a compact band with hRf value of 46. The method was linear in the range of 1-5 µg/band. The maximum yield of alpha-mangostin was obtained from the plant by hot extraction with methanol.

Pharmacophore 1(2), 103-111 (2010). HPTLC of wedelolactone in powdered dried aerial parts of Eclipta alba Hassk, extracted with methanol, on silica gel with toluene – ethyl acetate – formic acid 50:50:1. Quantitative determination by absorbance measurement at 351 nm.

62nd Indian Pharmaceutical Congress Abstract No. F-265 (2010). TLC of cholesterol on silica gel with carbon tetra chloride – methanol – formic acid 270:30:11. The hRf value was 55. Quantitative determination by absorbance measurement at 366 nm. The method was linear in the range of 100-600 ng/band.

Planta Med. 75, 711-718 (2009). For many decades, planar chromatography has been used for the analysis of plants, in particular today in its most advanced form of HPTLC. The technique is e. g. used for the identification of medicinal plants and dietary supplements, and for the detection of adulteration and quantitative determination of marker substances. Reliable qualitative and quantitative results can be achieved based on suitable instrumentation and adequate methodological concepts. The manageability of the entire planar chromatographic process has improved. Integration of biological detection systems as well as hyphenation to mass spectroscopy has widened the applicability of planar chromatography as an important analytical technique. The introduction is followed by explanation of HPTLC, use of HPTLC in plant analysis, limitations, applications (identification, detection of adulteration and quantitation), and instrumentation (chromatogram development, documentation, detection and evaluation).

J. of Qilu Med. & Pharm., 30 (2), 91-93 (2011). TLC of the extracts of Wuyangbuxin capsules 1) for Polygonium multiflorum, on silica gel with the upper phase of toluene - ethyl acetate - formic acid 10:1:1, detection under UV 365 nm; 2) for Licorice, on silica gel with petroleum ether (60-90 °C) - toluene - ethyl acetate - glacial acetic acid 20:40:14:1, detection by spraying with 10 % sulfuric acid in ethanol and heating until zones were detected; 3) for Milkvetch root, on silica gel with the lower phase of chloroform - methanol - water 13:6:2 at 10 °C, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C until zones were detected; 4) for Epimedium herb on silica gel with ethyl acetate - butanone - formic acid - water 10:1:1:1, detection by spraying with AlCl3 reagent, heating at 105 °C until zones were detected and viewing under UV 365 nm. Identification by fingerprint comparison with the standards of the individual drug components.