These are GC-MS contaminants from the column bleeding. Remember- the "siloxane" is a column matrix component and one should guard against identifying this as a compound from the plant extract. Silyl, silane, siloxane, siloxyl- are derivatives from column matrix. Octadecamethyl, and tetracosamethyl are also industrial/ isntrument- derived peaks comes that ones comes across. One way is to check if they are too abundant, and then change column, liner, septum etc and minimize use of derivatizing agents, solvents etc. One should use Golm-Database or NIST Database for matching the compounds and consult robust literature before assigning annotations to the compounds in such untargeted analyses approaches. Good luck.

These are GC-MS contaminants from the column bleeding. Remember- the "siloxane" is a column matrix component and one should guard against identifying this as a compound from the plant extract. Silyl, silane, siloxane, siloxyl- are derivatives from column matrix. Octadecamethyl, and tetracosamethyl are also industrial/ isntrument- derived peaks comes that ones comes across. One way is to check if they are too abundant, and then change column, liner, septum etc and minimize use of derivatizing agents, solvents etc. One should use Golm-Database or NIST Database for matching the compounds and consult robust literature before assigning annotations to the compounds in such untargeted analyses approaches. Good luck.

Dear Biswapriya,

        Thank you very much. Your reply is of really good information sir.

Dear Prashant

I am full agree with Biswapriya Answer.