Identification of volatile and non-volatile compounds

With advances in analytical techniques, the minimal criteria for conclusive identification of natural products have substantially increased. Compounds can no longer be identified solely on the basis of a retention time match with a synthetic chemical standard or a single mass spectrum library match. It is strongly suggested that the reader consult guidelines for natural product identification (Ducret et al., 2008). These guidelines outline how confirmation of compound identity should involve multiple methods (mass spectral matches by GC-MS EI, molecular mass determination by GC-MS CI, structure elucidation by NMR) and comparison with synthetic chemical standards whenever possible. These guidelines may appear stringent to someone not familiar with chemical ecology but are important to assure the quality of chemical identifications.