Anal. Chem. 61, 2516-2523 (1989). Combination of TLC and laser mass spectrometry (LMS) as an analytical technique. Detection of separated compounds directly from polyamide TLC plates by LMS. Demonstration of the application to aromatic hydrocarbons and purine bases. Polyamide does not interfere with compound identification by the mass spectrum owing to its low mass fragment ions (<m/z 150).

Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 23-32 (1991). Polystyrenes (PS) oligomer homologes with molecular weight up to 2000 were identified after TLC separation on silica with carbon tetrachloride - heptane - MEK 100:95:1 via MS.

Chromatographia 32, 179-181 (1991). TLC of nicergoline on silica with methylene chloride – acetone – water 100:10:1. Quantification by secondary mass spectrometry from the ratio of the fragment ion intensity of the nicergoline to the internal standard. Detection limit, 10 ng at signal-to-noise ratio of 5. The method is suitable for quantitative analysis of thermally unstable compounds or compounds of low volatility.

Chinese J. Chromatogr. (Sepu) 11, 27-29 (1993). TLC of extracts of Cytokinin on silica with butanol - isopropanol - NH3 - water 2:8:1:1. Detection under UV 254 nm. Identification by GC and GC-MS after elution with ethanol.

J. Planar Chromatogr. 6, 446-451 (1993). HPTLC of theophylline, caffeine, theobromine, 1,7-dimethylxanthine, diphylline, 1-methyluric acid, 3-methylxanthine, xanthine, hypoxanthine on silica (prewashed) with ethanol - 5% aqueous diethylamine solution 95:5 Quantification by densitometry at 275 nm (absorbance). Identification can be performed using on-line spectrophotometric methods (UV/VIS, FTIR, and Raman).

J. Food Hyg. Soc. of Jap. 34, 512-516 (1993). Description of reverse-phase TLC/FABMS method incorporating an analyte condensation technique for the identification of 12 coal tar dyes, using the magic bullet matrix (a 3:1 dithiothereitol-dithio-erythritol mixture). TLC of xanthene and other dyes on RP-18 with MEK - methanol - 5% aqueous sodium sulfate solution 1:1:1, and 2) methanol - acetonitrile - 5% aqueous sodium detection limit 150-fold with good reproducibility by using the condensation technique.

Anal. Chem. 67, 1805-1814 (1995). Presentation of a direct coupling protocol of TLC with matrix-assisted laser desorption ionization (MALDI) MS, including analyte extraction from TLC plate, its transport to the surface following matrix deposition and crystallization. Optimization of the extraction procedure. Evaluation of the MALDI matrices for use with silica and cellulose TLC plate. Discussion of the detection limits, the influence of ninhydrin on spectral quality, and suitability of TLC/MALDI method for direct TLC imaging.

J. Planar Chromatogr. 9, 84-91 (1996). Review of the use of tandem mass spectrometry (MS-MS) in combination with planar chromatography (TLC or HPTLC). Examples of the use of the technique with a wide range of synthetic compounds (drugs, plasticizers) and natural products (steroids, glycolipids) are provided. Ionization techniques for performing TLC-MS are described and critically appraised and practical aspects of the hyphenation of TLC and mass spectrometry are considered. Discussion of the advantages of MS-MS over simple MS techniques.