I have done GCMS of plant extract and unknown compounds were compared with NIST library 2004. Now how can I check their novelty and on which basis I can say this compound is noval?
Only known compounds for which mass spectrum is available in the NIST will be identified in your GCMS report, the unidentified compounds for which mass spectrum did not match for any compounds in the library may be taken as novel, but when it is unidentified there is no use even if it is novel.