Provides a comprehensive guide to the use of gas chromatography–mass spectrometry (GC-MS) on environmentally significant organic compounds This book presents a library of mass spectra of 1,725 biologically and environmentally important organic compounds, in the form of their trimethylsilyl derivatives (TMS), as well as their linear temperature programmed chromatographic retention indices, RI, whose values are in the range of 700-4700 index units. Of the compounds presented, more than 60% of compounds have not previously been characterized by their mass spectra, and more than 70% not previously been characterized by their RI values. Some of these compounds, never before analysed via MS and GC, were detected by the author’s team in plant tissues. The first chapters of the book are devoted to the methodology and practice of sample preparation, as well as to mass spectrometry considerations. They contain the discussion of possible complications and limitations of the method. The book includes lists of chemical compounds in alphabetical order, as well as in the order of their retention indices which facilitates the search for parameters of interest. Every compound in the book includes a RI value, mass spectrum, CAS number (if available), molecular and structural formula, formula weight, chemical name and list of synonyms, as well the source of compounds used for registration of spectrum and RI value. Features mass spectra and chromatographic retention indices of 1,725 organic substances in the form of their trimethylsilyl derivatives (TMS) Includes the CAS number, molecular and structural formula, formula weight, mass spectrum, chemical name and list of synonyms, and more for every compound covered within The first publication containing analytical parameters of high-boiling compounds such as glycosides, lignans, and phenylpropenoid glycerides with RI values >4000 GC-MS of Biologically and Environmentally Significant Organic Compounds will appeal to specialists in phytochemical analysis, food, and environmental chemistry, as well as other investigators dealing with GC or GC/MS analysis complex mixtures of organic compounds. The accompanying electronic database, "Biologically and Environmentally Important Organic Compounds - GCMS Library", will be published in mid-2020, ISBN: 978-1-119-60170-8.