Ein neues Argument für die Überprüfung der Droge. (Aloe as laxative. A new argument for the examination of the drug.) Deutsche Apotheker Zeitung 135, 1049-1052 (1995). TLC of aloin and aloe-emodin on NH2-bonded silica with ethyl acetate - methanol - water 100:17:13 or 70:17:13. Detection under UV 366 nm or by spraying with magnesium acetate solution. Quantification of aloin by densitometry at 370 nm and of aloe-emodin at 430 nm.

Planar Chromatogr. 8, 382 - 387 (1995). HPTLC of a polyoxyethylene glycerol trioleate nonionic surfactant (Tagat TO) on silica with MEK - acetone - water 50:5:X, X = 0, 3, 6, 9 in a twin-trough chamber. After drying detection by dipping into a solution containing copper(II)sulfate and phosphoric acid, followed by heating at 180°C for 20 min. Quantification by densitometry at 500 nm from the back of plate after covering the front with a glass plate. Detection limit 1.25 mg/mL. New sensitive, specific, and reproducible TLC method.

J. AOAC Int. 79, 628-635 (1996). TLC of allantoin in pharmaceuticals on silica with e.g. methanol - acetone - formic acid - water 40:2:1:6 and in urine on cellulose with butanol - acetic acid - water 2:1:1. Detection with pDMAB (Ehrlich's reagent). Quantification by densitometry at 445 nm. TLC as fast and inexpensive semiquantitative method for estimation of allantoin in natural samples.

J. Chinese Trad. Patent Med. (Zhongchengyao) 17 (8), 17-18 (1996). TLC of berberine on silica with ethyl acetate - butanone - formic acid - water 10:7:1:1. Detection under UV. Quantification by densitometry at 345 nm.

By thin-layer chromatography.) (Chinese). J. Chin. Trad. Med. (Zhongguo Zhongyao Zazhi) 20 (1), 9-10 (1995). TLC on silica with chloroform - methanol - formic acid 200:10:1. Quantification by densitometry at 320 nm. Recovery 96.9 %.

J. Chinese Pharm. Univ. (Zhongguo Yaoke Daxue Xuebao) 26, 279-281 (1995). TLC of bufonis on silica with benzene - acetone 7:3. Quantification by densitometry at 280 nm. RSD 3.9 %; recovery 100.6 %.

Merck KGaA (Ed.): Chromatographie - Chronologie einer Analysentechnik - Praxis, Status, Trends, GIT Verlag mbH, Darmstadt, 96-100, ISBN 3-928865-21-8 (1996). Correlation between instrumental thin-layer chromatography and GLP (Good Laboratory Practice). Each step in TLC, e.g. sample application, development, evaluation, pre- or post chromatographic derivatization, is fully automated. The advantages and possibilities of each automated step are discussed. Instrumental TLC shows good reproducibility and high flexibility. Documentation regarding GLP is demonstrated by reports. Automated validation of instruments is shown.

J. Chromatogr. A 754/1-2, 423-430 (1994). Description of HPTLC in the field of water analysis. A short review with 25 references on the analysis of pesticides by classical TLC is given. Explanation of the principle of automated multiple development (AMD) technique, with a separation number about three times higher than in classical TLC. The focusing effect, the gradient development from polar to unpolar, the increasing migration distances and the universal gradient are described. The strategy of the whole procedure which became a German standard is demonstrated from sample preparation (solid-phase extraction), screening, identification to final confirmation of positive results. With only one HPTLC plate up to 720 analytical answers can be given, that means 6 different standard mixtures of 10 pesticides each are applied on one plate together with twelve samples (screening of 12 samples for these 60 pesticides gives 720 analytical answers). Common gradients and separations of pesticide mixtures, as well as water samples containing pesticides are presented.