High-Performance Thin-Layer Chromatography Method for Assessment of the Quality of Combinatorial Libraries, and Comparison with Liquid Chromatography−Ultraviolet−Mass Spectrometry

Abstract

A high-performance thin-layer chromatography (HPTLC) method was developed for fast evaluation of the purity of solid-phase synthesis products. The results obtained were in good agreement with results obtained by the LC-MS method (r(2) = 0.8404) or by the LC-UV method (r(2) = 0.8053), confirming the suitability of HPTLC for purity analysis of combinatorial syntheses. The synthesis products can be quantified and identified by measuring UV densitograms or in situ UV spectra or by ESI-MS after isolation of the zone of interest. A new, simple, and fast method for transferring the zone of the analyte from the plate to the ESI-MS equipment is described. The new HPTLC method enables rapid and efficient analysis of approximately 40 samples in parallel. As such, it offers a cheaper and easier way to analyze the purity of synthesis products than the commonly used LC-UV-MS.

Analysis of small molecules by ultra thin-layer chromatography-atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry

“…TLC allows simultaneous analysis of many samples on one plate, the plates are disposable, and therefore memory effects can be avoided, solvent consumption is low, and a number of nondestructive detection methods with appropriate derivatization reagents can be used in sequence. The modern HPTLC technique, combined with automated sample application and densitometric scanning, has proven to be sensitive, reliable, and suitable for the qualitative and quantitative analysis of pharmaceutical, environmental, toxicological, forensic, and food samples [1][2][3][4][5][6][7][8][9].…”

“…In those cases in which the standard compounds are not available (e.g., the screening of new natural agents or combinatorial chemistry samples), the identification of unknowns has to be performed using a specific technique, such as mass spectrometric detection. The combination of TLC and MS has been a very active research area over the last few years [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. TLC-MS has most frequently been performed as an off-line process in which the sample is scraped and extracted from the plate before MS analysis [5,22,23], or is analyzed as such with the use of various in situ techniques [15, 16, 19 -21, 24 -31], the most common of these being TLC-liquid secondary ion mass spectrometry (LSIMS), TLC-fast atom bombardment (FAB), TLC-matrix-assisted laser desorption/ionization (MALDI), and TLC-surface-assisted desorption/ionization (SALDI).…”

Mass spectrometry analysis of new chemical entities for pharmaceutical discovery

“…Separation combined with MALDI–MS for small molecule analysis has been reported by several authors using ultra‐thin layer chromatography (TLC–MALDI) (Busch, 1992; Somsen, Morden, & Wilson, 1995; Weins & Hauck, 1996; Chen, Shiea, & Sunner, 1998; Wilson, 1999; Gusev, 2000; Mehl & Hercules, 2000; Hauck et al, 2001; Kálasz & Báthori, 2001; Hauck & Schulz, 2002; Wu & Chen, 2002; Crecelius, Clench, & Richards, 2003; Salo et al, 2003; Santos et al, 2004). In this approach, analytes were separated on TLC plates, which were then coated with matrix and subsequently introduced into the MALDI source.…”

“…In this approach, analytes were separated on TLC plates, which were then coated with matrix and subsequently introduced into the MALDI source. Salo et al (2003) used an atmospheric pressure MALDI (AP‐MALDI) source in order to reduce possible contamination of the mass spectrometer from introducing chromatographic material into a vacuum. All analyte spots were successfully ionized directly from the TLC plate.…”

Comparison of TLC and Different Micro TLC Techniques in Analysis of Tropane Alkaloids and Their Derivatives Mixture from Datura Inoxia Mill. Extract

“…Monolytical layers are thiner than HPTLC (10 μm). Development distance on UTLC plates is between 1 and 3 cm [8]. UTLC coupled with MS has been successfully used in analysis of peptides [9], amino acids, phenols [6] and coupled with AP MALDI-MS for analysis of other small molecules [10].…”