Rapid. Commun. Mass. Spectrom. 21, 3772-3776 (2007). A new fully automated online interface to couple HPTLC with ESI-MS/MS is presented for the first time. Among the major features of this interface are the time required for analysis, precision, suited for normal and reversed-phase layers and all plate sizes and carriers, no post-chromatographic process is required, it can be coupled universally with all LC-MS ion sources without any adjustment or mass spectrometer modification, and the quantitative analysis can be performed without any internal standard with a given detectability at the low-nanogram and even picogram level. The validation results for caffeine quantification in energy drinks and pharmaceutical samples, without internal standard, proved the reliability of the interface and its usefulness for quantitative analysis with comparable results to those obtained by validated HPTLC-UV methods.

J. Planar Chromatogr. 21, 367-371 (2008). HPTLC of harmane (1-methyl-9H-pyrido[3,4-b]indole) and Glu-P-1 (2-amino-6-methyldipyrido[1,2-a:3’,2’-d]imidazole) on silica gel (prewashed with methanol) in a flat-bottom chamber with diethyl ether - methanol 49:1 at a relative humidity of 42 % and a temperature of 26 °C. Before development, the activity and pH of the silica gel were adjusted in a saturated twin trough chamber with 20 % aqueous ammonia (25 %) for 15 min. Quantitative determination by fluorescence measurement at UV 366/>400 nm. HPTLC-MS coupling via an extractor-based interface using a circular and an oval plunger for extraction of the adjacent heterocyclic amines. The circular plunger was easier to position, however the oval plunger was shown to be optimal (more selective) for adjacent bands.

Rapid Commun. Mass Spectrom. 24, 2295-2304 (2010). HPTLC of glycosphingolipids (GSLs) on silica gel with chloroform - methanol - water 120:70:17. The plate was overlaid with Shiga toxin (Stx), and the microbes were detected with primary anti-Stx and appropriate alkaline phosphatase labeled secondary antibodies. Bound antibodies were visualized by color development using 0.05 % 5-bromo-4-chloro-3-indolyl phosphate p-toluidine salt in glycine buffer. The GSLs were extracted from the plate and analyzed by electrospray ionization mass spectrometry (ESI-MS). Using the combination of a TLC overlay assay and nanoESI-QTOF-MS, the structural characterization of the functional Stx1 receptors of Raji and THP-1 cells is reported.

Phytochem. Anal. 24, 1-24 (2013) The application of chemometrics in combination with chromatographic fingerprining was reviewed. The authors described how this combination allowed to find correlation between different variables such as molecular profile and genetic variability and their geographical origins and growing conditions.

J. Chinese Modern Med. & Pharm. 20 (31), 54-56 (2013). Paracetamol and chlorphenamine maleate granule are an anti cold medicine effective for cold induced nasal congestion, headache, sore throat, fever, etc. Artificial bezoar is one of the main ingredients and bilirubin is the key effective component in the medicine. For quality control, TLC of the extracts and bilirubin on silica gel with isooctane – ethyl acetate – glacial acetic acid 11:5:3, detection under white light. Quantitative determination of bilirubin by UV spectrophotometry. Demonstration by applying to real life samples from three pharmaceutical factories indicated that the method was suited for the quality control of the medicine.

Trends Anal. Chem. 82, 68-88 (2016). This review describes the application of ambient mass spectrometry for the analysis of pharmaceutical products and herbal medicines, including coupling TLC to DESI–MS for the analysis of analytes separated on TLC plates. The review also describes coupling TLC with direct analysis in real time (DART)-MS, which is easily achieved by positioning a TLC plate between the DART source and the MS inlet.

J. Chromatogr. Sci. 54 (7), 1096-1104 (2016). TLC of the extracts of the dried aerial parts of 12 plants of Cirsium species and five selected standards (naringin, apigenin, rutin, caffeic acid and chlorogenic acid) on silica gel with ethyl acetate – formic acid – acetic acid – water 24:3:3:8 on RP-18 phase with 5 % aqueous solution of formic acid – methanol 7:3 for the first development and the same system in the ratio of 1:1 for the second development. Analysis of the results by chemometrics. The comparison of individual Cirsium species and the identification of unknown species by using the similarity indices (Pearson's correlation coefficient, determination coefficient and congruence coefficient), distance indices (Euclidean distance, Manhattan distance and Chebyshev's distance) and Multi-Scale Structural SIMilarity. Based on chemometric analysis, the first extract of the widely grown species is identified as Cirsium arvense and the second one as Cirsium rivulare.

Phytochem. Anal. 30, 218-225 (2019). HPTLC of flavonoids in red wine, apple juice and rose flowers on silica gel with ethyl acetate – methanol – formic acid 90:10:1. Glycosylated flavonoids were identified by inorganic matrix‐assisted laser desorption ionisation time‐of‐flight mass spectrometry (MALDI‐TOF‐MS).