DART can be used with a heated gas stream to rapidly pyrolyze and identify low-volatility materials such as adhesives and resins, directly on surfaces. Although these materials are not pure compounds, a library of DART mass spectra can be created and searched to identify materials, and exact mass measurements coupled with accurate isotopic abundances can be used to identify unknown components. Examples are shown here for cured and uncured epoxies and acrylate adhesives on metal and glass.
All samples were analyzed by acquiring positive-ion mass spectra with the DART source operated with helium and a gas heater setting of 450° C (helium temperature ~350° C). All mass spectra were measured over the m/z range 60-1000 at a resolving power of 6000. Following each analysis, a glass rod coated with PEG 600 was placed in front of the DART source to provide a calibration for exact mass measurements. A nominal mass library of adhesive mass spectra was created by using the software link to the NIST version 2.0 mass spectra database search program. All figures shown here are copied from that library and only integer masses are shown although exact masses were recorded for all peaks.