Polyisoprenoids are hydrophobic long-chain polymers, consisting of several or tens of isoprene units, that play crucial physiological functions mediating membrane properties and cell metabolism. Prenols and dolichols (dihydro-prenols) are two classes of polyisoprenoids which are found in the cells. Due to their physico-chemical properties are less prone to undergo ionization in mass spectrometer’s ion source, which hinders the sensitivity of the analysis. Moreover, prenol and dolichol with the same number of isoprene units show overlapping mass spectra, which makes separation of their signals difficult and gives false results on analyte content levels. Thus, we have developed sensitive and highly selective LC-MS analysis of both prenol and dolichol which enables quantitative estimation of their content in different biological matrices. Our method couples chromatographic separation with Accucore C30 (Thermo Scientific) column, which provides high resolution, and Xevo TQ-MS mass spectrometer (Waters) resulting in high sensitivity. Supplementation of the eluting solvents with ammonium salt resulted in formation of ammonia adducts of prenols and dolichols [M+NH4] + which in turn increased the signal intensities. This technique was easily applied on Q-Exactive Orbitrap high resolution mass spectrometer (Thermo Scientific). Taken together, this analytical procedure is robust, MS-friendly and easily reproducible.
This study was partially supported by grants from the National Science Centre of Poland [UMO‐2018/29/B/NZ3/01033] (ES) and [UMO-2019/35/B/NZ1/03794] (LS)