Chinese J. Pharm. Anal. (Yaowu Fenxi Zazhi) 16, 267-268 (1996). TLC on silica with chloroform - methanol - NH3 40:10:1. Detection under UV 254 nm. Quantification by densitometry at 238 nm.

J. Planar Chromatogr. 11, 148-150 (1998). Simple and fast procedure for the quantitative determination of 3-b-OH, dimethyl triterpene derivatives in complex mixtures. TLC of a complex mixture of triterpenes (the mono-ols a-amyrin, b-amyrin, g-amyrin, taraxasterol, j-taraxasterol, lupeol, cycloartenol, and 24-methylenecycloartenol, and their acetate and palmitate derivatives on silica gel with cyclohexane - toluene - ethyl acetate 15:6:4). Detection by spraying with 3% sulfuric acid in ethanol and heating at 110°C for 10 min. Quantitation by densitometry in absorbance-reflectance mode.

GIT Fachz. Lab. 2, 96-98 (1998). HPTLC of hydrocortisone and cinchocaine (2-butoxy-4-quinolinecarboxylic acid(2-diethylamino)-ethylamide) after 15 min chamber saturation on silica gel with toluene - acetone - acetic acid - ethanol 40:30:5:2. Densitometry at 240 nm (absorbance). The intermediate precision (n = 3) was found to be at 0.53% (peak height) and 1.7% (peak area), respectively for hydrocortisone, and at 1.6% (peak height) and 3.3% (peak area), respectively for cinchocaine. Rapid and economic TLC procedure.

J. Chinese Herb. Med. (Zhongcaoyao) 28, 725-726 (1997). TLC on silica gel with benzene - methanol - acetic acid 34:2:1. Quantitation by densitometry at 318 nm. Precision within plate 1.95 % (n=5), plate-to-plate 2.77 % (n=5).

CBS 89, 12-15 (2002). HPTLC on silica gel with chloroform - methanol - water - ammonia 24% 65:30:4:2 over 90 mm with chamber saturation for 30 min. Detection by dipping in CuSO4/H3PO4 reagent for 8 s followed by heating at 170 °C for 10 min. Quantitative determination by absorbance measurement at 500 nm. Comparising operating costs the HPTLC analysis appears preferable for quality control of samples with known content. HPLC is more cost effective for the analysis of samples with unknown content.

CBS 90, 12-13 (2003). TLC of oxazoline Ia on aluminum sheets RP-18 with methanol over 10 mm, followed by water - acetonitrile 1:1 over 55 mm. Ion pair chromatography of oxazoline Ia with phosphate buffer - acetonitrile 1:1 over 60 mm after dipping in 2 mM cetyltrimethylammonium bromide. TLC of oxazoline Ib and Ic with phosphate buffer - acetonitrile - dioxane 4:3:3 over 65 mm. Determination by absorbance measurement at 200 nm (oxazoline Ia and Ib) and 262 nm (oxazoline Ic) respectively.

J. Chinese Trad. Patent Med. (Zhongchengyao) 26 (1), 19-23 (2004). TLC on silica gel in a basic developing system containing diethylamine. Detection by iodine vapour. Identification by standard comparison. Quantitative determination by densitometry at 340 nm. Validation of the method by investigation of the procedures, including sample preparation, mobile phase, visualization, scanning wavelength, linearity range (0.28-1.65 µg, r=0.9991), precision (RSD <1.4 % within plate and <2.4 % plate-to-plate), resolution, repeatability, reproducibility, and recovery (87.2 %-99.7 % for different medicine). Comparison of the results with those obtained by HPLC.

J. Chinese Trad. Patent Med. (Zhongchengyao) 11, 882-884 (2004). TLC on silica gel with 1) chloroform - methanol - conc. ammonia 80:4:1, 2) benzene - ethyl acetate 20:1, 3) chloroform - methanol - water 13:6:2, 4) ethyl acetate - formic acid - water 10:1:1. Detection 1) by spraying with 5 % solution of potassium iodobismuthate, 2) by spraying with 10 % H2SO4 in ethanol and heating at 105 ºC, 3) by spraying with 10 % H2SO4 in ethanol, heating at 105 ºC and under UV 365 nm, or under 254 nm. Identification by fingerprint techniques. Quantitative determination of matrine by densitometry at 520 nm. Validation of the quantitative method by investigation of its linearity range, reproducibility, repeatability, recovery.