- 第3日 5月17日（木） 14:25～14:45 B会場（星雲1）
Distribution and alteration of stabilizers contained in polymer materials were analyzed by matrix assisted laser desorption/ionization-mass spectrometry (MALDI‐MS) imaging. MALDI-MS imaging was performed using a high-resolution time-of-flight mass spectrometer with a spiral trajectory (JEOL JMS S3000). 2,5-dihydroxybenzoic acid (DHB) was used as a matrix reagent. Conditions and procedure were first evaluated for MALDI-MS imaging of stabilizers. In terms of signal intensity and uniformity in observed MS images, the combination of spraying the matrix solution and preliminary gold vapor deposition on the sample was proved to be effective as well as mixing of ammonium sulfate in the matrix solution and preliminary vapor deposition of the matrix. Under the optimized conditions, polypropylene (PP) film samples containing various amounts of an oligomer type hindered amine light stabilizer (HALS; Adekastab LA-68) were subjected to MALDI-MS imaging. The observed MS images clearly reflected the difference in HALS contents in the PP films. Furthermore, the UV irradiated sections of the PP films were obviously differentiated in the MALDI-MS images focusing on the MS signals of the oxidized HALS components.