Groundwork for Non Intentionally Added Photoinitiator Identification in Polyolefin Streams
Groundwork for identifying non-intentionally added photoinitiators in polyolefins requires high-resolution mass spectrometry and toxicological screening.
Liquid Chromatography Electrospray Ionization
Meaning
Mass spectrometry interface that converts liquid samples into a fine spray of ions for the chemical analysis of non-volatile polymer additives. It governs the ionization efficiency of large molecules and stops applying when the sample has entered the vacuum chamber of the mass spectrometer.
Sample Ionization
High voltage applied to the liquid stream creates charged droplets that evaporate to release individual analyte molecules. Liquid chromatography electrospray ionization is particularly effective for large, polar molecules like antioxidants or light stabilizers. This process allows for the detection of additives that are too heavy for gas chromatography.
The soft ionization technique preserves the intact molecular ion for accurate mass measurement.
Additive Quantification
Integration of the resulting ion peaks provides a measurement of the concentration of each substance in the polymer. Manufacturers use this data to verify that the resin contains the correct amount of protection against heat and sunlight. Consistent additive levels are necessary to prevent premature failure of the part.
The laboratory can detect multiple stabilizers in a single run.
Material Integrity
Analysis of the chemical extract reveals the presence of breakdown products or impurities from the manufacturing process. These findings help in troubleshooting issues like yellowing or loss of impact strength. A laboratory report using this method provides a detailed map of the non-volatile components.