Abstract

Poster Presentations

Day 3, May 21（Fri.）　　Room P2 (Zoom)

3P-58　　PDF

Structural Elucidation of a Causative Substance of Fishy Smell in Raw Water for Taps by Combining LC/HMRS with GC/HRMS

(¹Kagoshima Univ., ²Kagoshima Univ., ³Nat. Inst. Pub. Health)
^oYuta Shinfuku¹, Yamashita Yuki², Hirokazu Takanashi¹, Tsunenori Nakajima¹, Michihiro Akiba³

Off-flavor events in raw waters for tap water supply have been reported from various regions of Japan. Although fishy smell is the second most common off-flavor, its causative compounds is still unrevealed to the best of our knowledge. The authors previously reported one candidate substance and determined its molecular formula as C₁₃H₂₀O₃. Its partial structural elucidation was also performed, however, much effort is still required for complete identification. In this study, a detailed structural elucidation of C₁₃H₂₀O₃ was performed by combining GC/HRMS with LC/HRMS. GC/HRMS analysis suggested that C₁₃H₂₀O₃ contains a methoxy group, a cyclohexene ring, and two ketone groups. One of the two ketone groups is a terminal ketone to which a propyl or a butyl chain is attached.
Because we previously hypothesized that C₁₃H₂₀O₃ had a hydroxyl group instead of a methoxy group, alternative fragmentation pathways for three neutral losses (C₂H₂O, C₂H₄O, and C₃H₆O) which had been observed in our previous LC-HRMS analysis of the derivatized C₁₃H₂₀O₃ were also proposed adopting a methoxy group in order to get rid of this contradiction.