Laser desorption-ion mobility spectrometry as a useful tool for imaging of thin layer chromatography surface

•TLC technique was coupled with ion mobility spectrometry using laser desorption.•Ion mobility spectrometry (IMS) is more inexpensive than the MS methods.•Laser is focused onto a point much smaller than the TLC analyte spots.•Analysis of partially overlapped spots on TLC is achievable by this method.

We present a novel method for coupling thin layer chromatography (TLC) with ion mobility spectrometry (IMS) using laser desorption technique (LD). After separation of the compounds by TLC, the TLC surface was sampled by the LD-IMS without any further manipulation or preparation. The position of the laser was fixed and the TLC plate was moved in desired directions by the motorized micro-positioning stage. The method was successfully applied to analyze the TLC plates containing explosives (tri nitro toluene, 1,3,5-trinitro- 1,3,5-triazacyclohexane, pentaerythritol tetranitrate, 2,4-dinitro toluene and 3,4-dinitro toluene), amino acids (alanine, proline and isoleucine), nicotine and diphenylamine mixtures and detection limits for these compounds were determined. Combination of TLC with LD-IMS technique offers additional separation dimension, allowing separation of overlapping TLC analytes. The time for TLC sampling by LD-IMS was less than 80 s. The scan rate for LD is adjustable so that fast and effective analysis of the mixtures is possible with the proposed method.