Meaning
High-energy ionization method used to fragment and identify volatile organic compounds and polymer additives extracted from plastics. Utilizing electron ionization mass spectrometry allows chemists to match fragment patterns against digital libraries to identify plasticizers and stabilizers. It is limited to compounds that can be vaporized without decomposing.
Spectral Signal
Fragmentation occurs when a high-energy electron beam hits the vaporized sample molecules. This electron ionization mass spectrometry produces a unique fingerprint of ions that reveals the molecular weight of the polymer additives. Overlapping peaks from different stabilizers are resolved by comparing fragment ratios.
Analysis Limit
Molecular ions with low thermal stability often fragment completely, leaving no trace of the unfragmented parent molecule. When this happens, electron ionization mass spectrometry cannot easily determine the total molecular mass of the polymer additive. Alternative lower-energy ionization methods must be substituted when identifying delicate, high-molecular-weight compounds.
Contamination Detection
Tracking the migration of processing aids from the mold surface into the finished part relies on this identification method. This electron ionization mass spectrometry quickly identifies trace amounts of heavy-metal-free lubricants and release agents that might cause surface defects or adhesion failure in painted or metalized plastic parts, helping technicians adjust mold-release spray frequencies and cycle times to prevent excessive compound buildup on the tooling surfaces.
