leaf by high-performance thin-layer chromatography. J. Planar Chromatogr. 22, 225-228 (2009). HPTLC of negundoside on silica gel (prewashed with methanol) with ethyl acetate - methanol - water - glacial acetic acid 78:12:7:3 in a twin trough chamber saturated for 20 min. Quantitative determination by absorbance measurement at 267 nm.

Indian Drugs 46(2), 109-112 (2009). HPTLC of chloroform extracts of stem bark of Terminalia alata and Terminalia arjuna on silica gel with chloroform - methanol 9:1. Arjunolic acid and maslinic acid were used as marker compounds. Detection by treatment with vanillin-sulphuric acid reagent. Quantitative determination by absorbance measurement at 254 nm. The fingerprint profile along with other physico-chemical data helped in the correct authentification and standardization of both plant species.

by HPTLC. Abstract No. 9191, IHCB (2009). HPTLC of (-)hydroxy citric acid (the main constituent of Garcinia gummigutta fruits) on silica gel with n-propanol - water - glacial acetic acid 50:50:1. Quantitative determination by absorbance measurement at 210 nm. The hRf value was 46. The method was linear in the range of 100-1000 ng/spot, recovery was 99.8-100.9 %.

60th Indian Pharmaceutical Congress PA-226, (2008). HPTLC of Neem (active ingredient of Nimbidin capsules) on silica gel with chloroform - ethyl acetate 4:1 containing 1 % of acetic acid. Quantitative determination by absorbance measurement at 254 nm. The chromatogram showed two active constituents in Neem with hRf values of 33 and 55. Linearity was in the range of 2-20 µg. The method was suitable for estimation of different constituents of Neem in herbal formulations.

J. Pharm. Biomed. Anal. 46, 391-394 (2008). TLC of conessine on silica gel with toluene - ethyl acetate - diethyl amine 13:5:2 in a twin trough chamber saturated at 25 °C. Detection by treatment with modified Dragendorff’s reagent. Quantitative determination by absorbance measurement at 520 nm. The hRf value of conessine was 82. Linearity was in the range of 1-10 µg/zone with a correlation coefficient of 0.9998 via peak area.

J. Planar Chromatogr. 22, 301-304 (2009). Analytical and preparative TLC of luteolin-7-rutinoside and luteolin-7-neohesperidoside on silica gel with ethyl acetate - formic acid - acetic acid - water 100:11:11:23, on cellulose with 30 % acetic acid, and on polyamide with chloroform - methanol - 2-butanone - acetyl acetone (= pentane-2,4-dione) 9:4:3:1. Detection by spraying with natural products reagent followed by treatment with PEG 4000, or by aniline phthalate.

60th Indian Pharmaceutical Congress PA-223 (2008). HPTLC of curcumin, demethoxycurcumin and bis-demethoxycurcumin on silica gel with chloroform - methanol 19:1. The hRf values were 25, 38, and 61 for bis-demethoxycurcumin, demethoxycurcumin, and curcumin respectively. Quantitative determination by absorbance measurement at 420 nm. The method was linear in the range of 50-400 ng/spot (curcumin), 10-150 ng/spot (demethoxycurcumin), and 5-40 ng/spot (bis-demethoxycurcumin). Recovery was in the range of 99.2-100.5 % for all three compounds.

f.) Etting. J. Planar Chromatogr. 23, 104-107 (2010). TLC of (+)-catechin, ellagic acid, quercetin, and ferulic acid on silica gel with toluene - ethyl acetate - fomic acid 6:4:1 in a twin-trough chamber previously saturated for 30 min at 25 °C. Other mobile phase compositions were ethyl acetate - methanol - water 10:1:1, n-butanol - acetic acid - water 4:1:5 (upper layer), n-butanol - ethanol - water 20:5:11, n-butanol - acetic acid - water 6:2:1, toluene - ethyl acetate - formic acid 5:5:1 and 7:3:1, and toluene - ethyl acetate - methanol - formic acid 140:60:1:1. Quantitative determination by absorbance measurement at 320 nm. Detection by dipping in anisaldehyde reagent, followed by drying and heating at 110 °C for 5 min. Characteristic bands of (+)-catechin, ellagic acid, quercetin, and ferulic acid were observed at hRf 35, 41, 63 and 66, respectively. Precision (CV, n = 7) was 0.39, 0.44, 0.55 and 0.16 % and repeatability (CV, n = 7) 0.65, 0.95, 0.37 and 0.18 %, respectively. LOD was 54, 340, 48 and 78 ng/band, and LOQ 4.1, 6.5, 1.6 and 1.5 µg/band, respectively. Linear regression was 0.9993 (100-500 ng/band), 0.9883 (1000-5000 ng/band), 0.9989 (100-500 ng/band) and 0.9987 (100-500 ng/band), respectively.