J. of Chromatogr. A 1218 (37), 6540-6547 (2011). New approach and application of highly automated planar chromatographic tools for powerful clean-up, called high-throughput planar solid phase extraction (HTpSPE), which is indispensable for preventing matrix effects in multi-residue analysis of pesticides in food by liquid and gas chromatography coupled to mass spectrometry, employing TLC to completely separate pesticides from matrix compounds and to focus them into a sharp zone, followed by extraction of the target zone by the TLC-MS interface, thus resulting in extracts nearly free of interference and free of matrix effects, as shown for seven chemically representative pesticides in four different matrices (apples, cucumbers, red grapes, tomatoes), and completion of clean-up of one sample in a manner of minutes. Regarding the clean-up step, quantification by LC–MS with mean recovery (against solvent standards) of 90–104% and relative standard deviations of 0.3–4.1% (n = 5) for two spiking levels of 0.1 and 0.5 mg/kg.

(Hungarian). (Measurement of triazine pollution, endangering the rotation of maize and wheat by using analytical and biological methods.) TLC of triazine on silica with toluene - acetone 85:15. Detection with chlorotoluidine. Detection limit 0.05 mg/kg triazine.

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.