Rationale
Direct analysis in real time mass spectrometry (DART‐MS) provides qualitative information about additives and polymer composition. However, the observed mass spectra are dependent on sampling conditions, in particular the DART gas temperature. This report describes the combination of a heated sample stage with DART‐MS for polymer characterization.
Methods
Industrial polymers with different compositions were examined by thermal desorption and pyrolysis (TDPy) DART. Samples were heated on disposable copper stages from ambient temperature to 600°C, and the evolved gases were introduced directly into a DART ion source through a glass tee. Time‐ and temperature‐dependent mass spectra were acquired using a high‐resolution time‐of‐flight mass spectrometer. Kendrick mass analysis was applied to the interpretation of complex mass spectra observed for fluorinated polymers.
Results
Positive‐ion DART mass spectra of common polymers exhibited peak series differing by monomer masses, often accompanied by a peak corresponding to the protonated monomer. Even polymers that did not exhibit a clear series of peaks produced characteristic mass spectra. Positive‐ion and negative‐ion mass spectra were recorded for fluorinated polymers, with polytetrafluoroethylene (PTFE) producing only negative ions. Thermal desorption provided characteristic temperature profiles for volatile species such as polymer additives and polymer pyrolysis products.
Conclusions
In comparison with direct analysis by positioning sample directly in the heated DART gas stream, TDPy DART provides a more versatile sampling method and provides thermal separation and profiling of polymer additives, intact short polymer chains, and pyrolysis fragments.
Rapid and accurate analysis of drugs using direct analysis in real time-mass spectrometry (DART-MS) combined with thermal desorption pyrolysis (TDP/DART-MS) is described in this chapter. Rapid drug screening is very important in cases of suspected drug abuse. However, acquiring accurate analytical data requires highly optimized sample handling and technical expertise. Although rapid drug analysis using mass spectrometry provides reliable data, it is not commonly used because of its complexity. Thus, a comprehensive analysis system for drugs that requires minimal optimization of sample preparation and analytical conditions is strongly desired. DART-MS involves ambient ionization mass spectrometric analysis with little to no sample preparation. We have coupled this approach with thermal TDP/DART-MS and demonstrate how it can be used to detect drugs in complex matrices such as urine or blood.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.