Structure analysis of unknown compound in oyster using HS-SPME-GC-TOFMS
Introduction
Oysters are a shellfish that are eaten all over the world because of their rich flavor and delicious texture. Oysters have a unique odor, and previous study has revealed that this odor comes from (Z)-1,5-Octadien-3-ol (Oyster Alcohol, Figure 1)1). In this previous study, oyster extracts were analyzed using a nuclear magnetic resonance spectrometer (NMR) and aroma components were analyzed using a gas chromatograph mass spectrometer (GC-MS), and (Z)-1,5-Octadien-3-ol was synthesized for final confirmation and identification.
GC-MS is often used to analyze aroma components. In qualitative analysis using GC-MS, compound identification is commonly performed by library search using commercially available electron ionization (EI) mass spectral database (DB) like NIST DB. However, 1,5-Octadien-3-ol is an “unknown compound” that is not registered in the NIST DB. In this case, the molecular formula of even an unknown compounds can be determined by using a time-of-flight mass spectrometer (TOFMS) as a mass spectrometer and performing an "integrated analysis" that combines electron ionization and soft ionization2). Furthermore, by using automated structure analysis software named “msFineAnalysis AI” which uses artificial intelligence (AI) to predict EI mass spectra from chemical structures, it is possible to estimate the structural formula3)
Therefore, in this MSTips, we used msFineAnalysis AI to analyze the unregistered compound "1,5-Octadien-3-ol" in the DB, and confirmed the accuracy with which the corresponding structure could be obtained.