Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (4), Appendix 2-5 (2004). TLC of Lidan capsule extracts on silica gel with 1) ethyl acetate - butanone - formic acid - water 5:3:1:1; 2) chloroform - methanol - water 30:10:1; 3) petroleum ether (60-90 ºC) - ethyl acetate - benzene 14:3:3; 4) n-hexane - chloroform - methanol 15:8:2. Detection 1) by spraying with 1 % FeCI3 in ethanol; 2) by spraying with a solution of P-dimethylaminobenzaldehyde - ethanol - H2SO4 1:100:10; 3) by spraying with 5 % vanillin - H2SO4 solution followed by heating; 4) by exposing to iodine vapor. Identification by fingerprint technique. Quantification of emodin and chrysophanol by HPLC.

Chinese J. Trad. Patent Med. (Zhongchengyao) 26 (1), 16-19 (2004). TLC of neutral sugars, rhamnose, xylose, and glucose, extracted from Ulva pertusa alga, on silica gel with n-butanol - ethyl acetate - isopropanol - acetic acid - water - pyridine 7:20:12:7:6:6. Detection by spraying with a solution of aniline hydrogen phthalate (0.93 g) – phthalic acid (1.66 g) – water saturated n-butanol (100 mL), followed by heating at 110 ºC for 10 min. Identification and quantification by comparison with the standards. Application of an orthogonal test to investigate the effects of four factors (volume of water, temperature, extraction time, and pH) on the yield of the compounds, and determination of the optimum extraction conditions.

J. Planar Chromatogr. 17, 286-289 (2004). HPTLC of isoquercitrin, avicularin, rutin, apigenin 7-glucoside, naringin, and hesperidin on silica gel with ethyl acetate - methanol - formic acid 90:10:1. Detection under UV light at 254 nm and by spraying with 1 % methanolic diphenylboric acid beta-ethylamine ester, followed by spraying with 5 % ethanolic polyethylene glycol 4000. Quantitative determination by densitometry at 254 nm. Report of the possibilities and advantages of HPTLC for investigation of hydrolysis.

J. Planar Chromatogr. 17, 169-172 (2004). HPTLC of omeprazole and pantoprazole and their impurities omeprazole sulfone and N-methylpantoprazole on silica gel with chloroform - 2-propanol - 25 % ammonia - acetonitrile (108:12:3:40). Detection under UV light at 254 nm. Quantitation of omeprazole and omeprazole sulfone at 300 nm and of pantoprazole and N-methylpantoprazole at 295 nm in reflectance-absorbance mode. Regression coefficients (r > 0.998), recovery (90.7 - 120.0 %), and detection limits (0.025 - 0.05 %) were validated and found to be satisfactory.

IPC 56th 2004, Abstract No. DP-33. An HPTLC method is reported for the standardization of Trikatukuc Curanam, an Ayurvedic preparation with Piper nigrum and Piper longum, both containing piperine as major alkaloid. HPTLC of piperine on silica gel with toluene - ethyl acetate 7:3 .Extraction with methylene chloride, the evaporated residue of the organic layer was taken in ethyl acetate and subjected to the analysis.The band corresponding to piperine was scanned at 338 nm. Linearity was 8-40 ng with recovery of 99.03 %.

56th IPC 2004, Abstract No. GP-47. Stability indicating HPTLC determination of oxcarbazepine in tablet dosage form on silica gel with toluene - methanol 4:1. The Rf value of oxcarbazepine was 0.17. Quantitative determination by scanning at 255 nm. The compound was subjected to acid and alkali hydrolysis, oxidation, dry heat, and photo degradation. All degraded products were well resolved from the pure drug. The method was validated for accuracy, precision, linearity, robustness, and recovery.

Part 2. Systematic errors caused by separation systems. J. Planar Chromatogr. 18, 118-126 (2005). Discussion of systematic errors in analytical PLC data. Second part of a series covering fundamentals of systematic quantitative errors caused by separation systems, evaluation and calibration errors, nonlinear separation and quantitation techniques, the sf4 procedure for finding total systematic errors, systematic errors caused by regulations, and conclusions and proposals for quantitative planar liquid chromatography. 1) Great number of different separation systems. 2) Separation system and mobile phase. 3) Multiple and forward-backward runs - circular and linear systems. 4) Fast and small is better and reduces systematic errors. 5) Type of separation system and quantitation mode. 6) Clean calibration substances available through a special mode of separation. 7) The gas phase in PLC. 8) Fundamentals of different separations systems (1. Important factors 2. Summary). 9) Possibilities and trends and the state of the art today; proneness to errors number (PEN).

CBS 95, 2-4 (2005). TLC of seven biogenic amines (extracted with trichloroacetic acid from fish, followed by dansylation with dansyl chloride) on silica gel (prewashed with developing solvent) with benzene - chloroform - triethylamine 10:6:7 or 10:6:2 in horizontal developing chamber over 90 mm. Quantitative determination by fluorescence measurement at 365 nm/> 400 nm. Calibration using peak area, LOD 7.5 mg/kg, LOQ 56 mg/kg.