TLC/MALDI for Identification and Separation of Monosubstituted and Disubstituted Nitrobenzoic Acids

摘要

Thin-layer chromatography and matrix-assisted desorption/ionization are used in this work to analyze and to separate monosubstituted and disubstituted nitrobenzoic acids. Parameters of chromatographic process were calculated due to the possibility of visualization of the mass spectrometric method. The data indicate that the mobility coefficients for meta-nitrobenzoic and 3,5-dinitrobenzoic acids differ by approximately two times, and the separation factor is 0.67. It was found that the thickness of a stationary phase (silica gel) of a factory plate for thin-layer chromatography should be decreased to increase the sensitivity of the analysis. It is recommended, therefore, to mechanically remove a small layer of silica gel before starting the analysis. Silica gel acts as a matrix during mass spectroscopic analysis.