Thin Layer Chromatography-Laser Mass Spectrometry (TLC-LMS) of Triphenylmethane Dyes: Initial Results

Laser mass spectra (LMS) of triphenylmethane dyes were obtained directly from a thin layer chromatographic (TLC) plate using the LAMMA-1000 laser microprobe. Spectra obtained from TLC plates were very similar to those obtained from standard substrates, the only difference being that at threshold power densities spectra from the TLC plates show greater fragmentation. The region below m/z 100 is mostly obscured by peaks due to the chromatographic support; above this range, peaks can be identified corresponding to the molecular cation and simple neutral losses. The inherent lateral rèsolution of the Instrument (∼5 μm) was used to resolve multiple components in broad chromatographic spots. The TLC-LMS combination has the advantage that components can be identified even if they are not completely resolved chromatographically.