J. Planar Chromatogr. 17, 420-423 (2004). A new on-line TLC-MS interface, with computer-controlled extraction of substances from selected spots on a TLC or HPTLC plate, has been constructed. The controlled collection of the sample and its programmed injection into the mass spectrometer is the advantage of this type of interface. It has been tested and validated with a standard solution of caffeine as test substance. HPTLC of caffeine on silica gel with dichloromethane - methanol 9:1. Quantification with a video-documentation system.

J. Chromatogr. A 1155 (1), 112 - 123 (2007). Presentation of a novel strategy for the fractionation of complex peptide mixtures using two-dimensional planar electrochromatography/thin-layer chromatography. Migration of phosphopeptides is slower in the first dimension, based upon their anionic phosphate residues, and certain predominantly acidic phosphopeptides even migrate in the opposite direction, relative to the bulk of the peptides. Further distinguishability of phosphopeptides are based upon hydrophilicity in the second dimension, which permits a restricted region of the plate to be directly examined for the presence of phosphopeptides by mass spectrometry. Phosphopeptide analysis from the plates by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-MS and tandem MS enabled peptide sequencing and identification.

J. Planar Chromatogr. 21, 15-20 (2008). TLC and OPLC of polyacetylenes of chamomile, trans-resveratrol, salicylic acid, and ochratoxin A on silica gel (preconditioned at 120 °C for 3 h) with chloroform - methanol 20:1. Detection by bioautography with Pseudomonas savastanoi pv. phaseolicola race 6 and by immersing the humid plate into MTT solution for 5 s.

Anal. Chem. 79, 2778-2789 (2007). TLC of alkaloids (berberine chloride, palmatine chloride, hydrastine, tetrahydroberberine, hydrastinine hydrochloride and jatrorrhizine) on silica gel with ethyl acetate - methanol - formic acid - water 50:10:6:3. Detection under UV 254 nm. Detection levels were 5 ng/zone each or 14-28 pmol. Desorption electrospray ionization mass spectrometry was investigated as a means to qualitatively identify and to quantify analytes directly from developed normal-phase TLC plates.

CBS 103, 13-15 (2009). HPTLC of azo dyes (Sudan I, II, III, IV, B, Sudan orange G, Sudan red 7B, Para red) in spice samples on caffeine impregnated silica gel with isohexane - methyl ethyl ketone 5:1 with chamber saturation for 10 min. Densitometric absorption measurement at 390, 415, 500, 525 and 550 nm. The limits of detection were approx. 10 mg/kg. Confirmation of suspected compounds in samples by comparison of UV spectra. TLC-MS analysis in positive ESI mode further confirms positive findings.

J. AOAC Int. 96, 1175-1188 (2013). Review of different methods for antifungal screening. Latest developments in HPTLC, where the correlation of bioactivity and quantification was needed to evaluate the antifungal potential. TLC-bioautography was presented as a simple way to screen antifungal activities and two visualization approaches for this technique were described, as well as recent TLC antifungal bioautography applications.

Rapid Commun. Mass Spectrom. 29, 1242-1252 (2015). The paper describes the application of adding neon into helium for Direct Analysis in Real Time (DART) leading to plasma glow visualization to track the metastable gas distributions during surface scanning. The method allows for optimal selection of the coordinates for DART-MS analysis without loss in signal intensity. Visualization of the impact region of the excited gas stream is of high importance for further developments of planar chromatographic hyphenations with DART-MS.

J. of Chromatogr. A 1441, 126-133 (2016). Presentation of a method for the analysis of ergot alkaloids including an ammonium acetate buffered extraction step, followed by a fast liquid-liquid partitioning pre-cleaning and then planar solid phase extraction (pSPE). HPTLC on amino phase with methanol for separation of the ergot alkaloids from the remaining matrix and for focusing them in a single zone. Quantification after dipping the plate in n-hexane – paraffin solution for fluorescence enhancement. The LOD and LOQ was 0.07 and 0.24 mg/kg rye, respectively, expressed as ergocristine, which was well below the currently applied quality criteria limit for rye. The recovery was almost 100 % at relevant spiking levels for different rye flour samples. The pSPE–FLD method was fast, efficient and reliable for screening the total ergot alkaloid content in rye and it was a rapid alternative to the HPLC determination with summing up the individual alkaloids. Furthermore, HPTLC-MS additionally enables the identification of the ergot alkaloid composition by a single mass spectrum, when utilized as a fingerprint, offering an easy differentiation of Secale cornutum from different origins.