Mass Spectrometric Identification of Cyclic Polysulfides in Sediment from the Eastern Gulf of Finland. II

Abstract

Nine polysulfides, previously unknown as environmental organic pollutants, were analyzed from a sediment sample from the Eastern Gulf of Finland. The determinations were done by gas chromatography connected to low- and high-resolution mass spectrometers. The structure of the polysulfides was elucidated by determination of the isotopic composition of abundant molecular and fragment ions by high-resolution mass spectrometry (HRMS), the interpretation of ion structures in low-resolution mass spectra (LMRS) using the thermochemical approach, the application of fragmentation rules and performing the ICLU simulation of abundance of ions in isotope clusters. Seven compounds were known from the literature, but mass spectra were reported for only two of them, both recorded from a mixture. Structure evaluation was successful for other substances, but not for the substance(s) in the first eluting GC peak, where HRMS data were not obtained. Suggested structures of the cyclic compounds were (in the order of GC retention) 3,4-dithiacyclohexene, 1,2,3-trithiacyclohexane, 3,4,5-trithiacyclohexene, 1,2,4-trithiacyclohexane, cyclopropyl hydrodisulfide, 1,2-dithiole-3-thione and 1,2,3,4,5-penta-thiacyclo-octane. One acyclic congener identified was dimethyl tetrasulfide.