Identification of the byproducts in the preparation of 2,6-naphthalenedicarboxylic acid by UPLC-QTOF MS/MS

摘要

Production of high quality polyethylene naphthalate (PEN) requires 2,6-naphthalenedicarboxylic acid (2,6-NDCA) with high purity. The selective synthesis of 2,6-NDCA was achieved by oxidizing 2,6-diisopropylnaphthalene and further purified by hydrofining process. The impurities in 2,6-NDCA products may have a negative effect on the degree of polymerization and molecular weight distribution of PEN. The ultrahigh-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS_ system is currently the most widely used technique for non-target organic residue analysis with high mass resolution and accuracy achieved by quadrupole time-of-flight mass spectrometry (QTOF MS). In the present study, UPLC-QTOF MS/MS was successfully applied for unknown byproducts identification both in oxidation and hydrofining process for 2,6-NDCA synthesis.