Development of a condensation technique for thin‐layer chromatography/fast‐atom bombardment mass spectrometry of non‐visible compounds

In Order to prevent the diffusion of sample when a matrix is deposited on the sample spot on a thin‐layer chromatography (TLC) plate and to obtain constructively high sensitivity in mass spectrometry, we developed a conedensation technique including ‘trapezoid technique’ for TLC/fast‐atom bombardment mass spectrometry (FABMS) on both silica gel and C18 plates. For colored samples and colorless samples having a chromophore, the condensation technique previously in use, that condenses the sample towards the center of the spot in a line, using methoanol, was effective. The trapezoid condensation technique has been newly developed for colorless compounds having no chromophore. The mass spectra obtained using this technique clerly showed molecular ion species at relatively lower concentrations of samples, and the technoique can improve the detection limits of molecular ion species in TLC/FABMS by 3‐100 times with good reproducibility.