General results and isolation of lignin metabolites. J. Agric. Food Chem. 32, 1237-1241 (1984). Separation of pentachlorphenol and metabolites on silica with hexane - ether - formic acid 70:30:4, cyclohexane - acetone 5:2 and chloroform as eluent. Detection and quantification by radioautography.

J.A.O.A.C. 72, 512-514 (1989). TLC separation of synthetic pyrethroids on silica. Detection by spraying the dry plate with NaOH solution (0.5N NaOH in 90% methanol), than with p-nitrobenzaldehyde solution (0.3 g p-nitrobenzaldehyde in 10 mL methyl cellosolve) and finally with o-dinitrobenzene solution (0.25 g in 10 mL methyl cellusolve). Detection limit 0.1 µg.

J. Planar Chromatogr. 3, 504-510 (1990). Multiple and stepwise development combined with gradient elution as a highly suitable method for the systematic determination of crop protection agents. The migration distance is highly reproducible (on the same HPTLC plate and on different ones). Screening and confirmation gradients coupled with reflectance spectroscopy (multiwavelength scanning) and postchromatographic, microchemical derivatization make it possible to detect crop protection agents in drinking, table, and ground waters. At least 100 substances can be checked for their presence on one HPTLC plate. Example: HPTLC separation of 21 crop protection agents in ground and drinking water with AMD. Two 23-step gradients (33 runs) based on acetonitrile, dichloromethane, hexane, formic acid, NH3 25% and on tert buthyl methyl ether, acetonitrile, hexane, formic acid, NH3. Multiwavelength scanning by adsorbance at 190, 220, 240, 260, 280, and 300 nm

J. AOAC Int. 78, 585-591 (1995). After separation of sample components by TLC, the area corresponding to the Rf of the compound of interest is scraped off and eluted with immunoassay buffer. The ability of TLC to separate a series of compounds coupled with immunoassay determination of samples in parallel can provide an efficient, inexpensive, and rapid means of quantifying samples in more complex matrices.

Merck KGaA (Ed.): Chromatographie - Chronologie einer Analysentechnik - Praxis, Status, Trends, GIT Verlag mbH, Darmstadt, 222-230, ISBN 3-928865-21-8 (1996). Description of the experimental practice of the German standard DIN 38407, part 11, the field of usage and the steps of the whole procedure. Reasons for the determination limit of the procedure of 50 ng/L are given. Critical points and factors of influence are demonstrated during handling of the samples after sampling, during solid phase extraction, concentration of the eluate and AMD chromatography. The stepwise confirmation of positive results and thereby the flexibility of the method are shown.

J. Planar Chromatogr. 11, 353-356 (1998). A mixture of ten pesticides - MCPA, atrazine, propham, chloropham, ofurace, triadimefon, biteranol A, biteranol B, tetramethrin, and a-cypermethrin - has been separated by two-dimensional development on cyano HPTLC plates with a polar mobile phase (methanol - water 3:2) in the first direction and a nonpolar mobile phase (hexane - ether 1:1) in second dimension. Chromatograms were recorded with a sensitive color CCD camera and evaluated with a software. Two quantification modes were compared - scanning of the whole plate and scanning of manually defined bent tracks. The precision of video-densitometric quantitation of the 2D chromatogram, expressed as the repeatability of image capturing and track setting, was determined.

J. Planar Chromatogr. 14, 283-290 (2001). TLC of chlorpyrifos, cypermethrin, dimethoate, endosulfan, fenvalerate, and phosphamidon on silica gel, soil and mixed layers with aqueous ammonium or sodium salt solutions, with or without added N-cetyl-N,N,N-trimethylammonium bromide (CTAB), with pure organic solvents, and with aqueous CTAB systems.

J. Planar Chromatogr. 18, 39-43 (2005). Micropreparative TLC of 10 pesticides (isoproturon, diuron, momolinuron, desmetryn, methiocarb, atrazine, fenitrothion, terbutryn, bromopropylate, aziprotryne) for preliminary fractionation on silica gel in horizontal DS chambers with tetrahydrofuran - n-heptane 1:4; detection under UV at 254 nm. HPTLC of the separated fractions on RP-18 W with methanol - water 3:2 and acetonitrile - water 3:2; densitometry at 254 nm.