J. Planar Chromatogr. 28, 190-204 (2015). The analysis of multiple pesticide residues in environmental samples is often impossible in a single-step process. Comprehensive 2D planar chromatography on mono and bilayers, coupled-layer chromatography, combination of multidimensional planar chromatographic techniques, hyphenated methods are proved to be suitable.

J. of Chromatogr. A 1415, 155-160 (2015). Presentation of a technique for direct analysis of raw samples by TLC coupled with electrospray ionization mass spectrometry (ESI-MS) instead of conventional MS analysis, which for raw samples commonly requires time-consuming and laborious sample pretreatment and separation using HPLC or GC. The analytes of interest could be extracted, ionized and detected by ESI-MS with much reduced matrix interference because the interfering compounds were retained by the sorbent material of the TLC plate. Demonstration by applying in direct analysis of samples containing common interfering compounds, e.g. salts and detergents. Rapid detection and quantification of target analytes in raw samples showed that the TLC-ESI-MS method was simple, rapid, efficient and could be effectively applied in offline and online separation and detection of different components in raw samples, e.g. plant extracts.

J. Chromatogr. A 1462, 134-145 (2016). Development of simple method for the separation of different colored pigment formulations used in the printing materials on food packaging to control the quality and safety of the package. HPTLC on silica gel by automated multiple development with a 9-step gradient based on ethyl acetate, methanol and water, and ending with toluene. Good resolution of differently soluble constituents of the pigment formulation like additives and coating materials. The results obtained by multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes, enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Characterization of single unknown pigment constituents by HPTLC-MS and HPTLC combined with ATR-FTIR. The new HPTLC method for routine quality control for incoming pigment batches and monitoring of internal pigment production processes secures a consistent pigment composition, resulting in consistent ink quality. Hyphenation of HPTLC with the Aliivibrio fischeri bioassay revealed information on the toxicological potential of different pigment compounds which helps guarantee consumer safety, especially in regard to readily permeable pigment components.

J. Sep. Sci. 42, 415-430 (2019). Review of the application of TLC hyphenated with mass spectrometry for the analysis of low-molecular-mass solutes. Different monolithic layers and their main applications were also described, including plates with thin inorganic layers, composite silica/organic polymer layers and porous polymeric monolithic layers (thermally initiated and prepared by photopolymerization). Methods of detection in TLC-MS systems were also described as indirect and direct mass spectrometric analyses.

Elution with ethanol - hexane 1:10. Quantitatiom by specrophotometry. Also TLC-densitometry for alpha- beta-carotene.

TLC of mononucleotides on silica with isopropanol - NH3 - water 12:8.3. Determination by spectrophotometry at 250 nm after elution.

J. Planar. Chromatogr. 1, 252-254 (1988). TLC on BaSO4-CaSO4, impregnated with coconut oil. Detection by spraying with an ethanolic solution of bromophenol blue (0.1%). Quantification by spectrophotometry 520 nm after elution. Detection limit, 400 µg (!).

Contribution to qualitative and quantitative identification.) (German). Deutsche Arzneimittel Zeitung 128, 1991-1994 (1988). TLC on silica with dichloromethane - methanol - NH3 85:14:1. Visualization with hydrogen peroxide (30%) solution, heating at 120°C for 30 min. and by spraying with acetic anhydride reagent (acetic anhydride - petrol ether - toluene 1:4:5) and heating at 120°C for 30 min. Detection limit, 0.5 - 1.0 ppm.