Mass Spectrometry Detection of Nitrobenzoic Acids and Their Salts on the Surface of Construction Materials

Abstract

The application of mass spectrometry to the detection of m-nitrobenzoic and 3,5-dinitrobenzoic acids and their salts on the surface of construction materials used in rocketry is described. Analytes are washed with acetonitrile from the studied surface and then analyzed by HPLC−MS with electrospray ionization or the matrix assisted laser desorption/ionization (MALDI). For electrospray ionization, the limit of detection is 6 μg/L and for MALDI ionization, 2 μg/L. The MALDI technique also ensures the direct investigation of samples without washing out; in this case, mass spectra can be visualized by constructing 2D diagrams of the distribution of nitrobenzoic acids over the surface.