Question

In our organic chemistry lab we were given an unknown. The professor gave us a mass spec for the unknown that he pulled from the webbook.nist.gov website. I ran an IR and I am having a hard time trying to figure out what it could be... I believe the mass spec is missing the parent ion. The closest chemical I've found to match the mass spec is methyl isobutyl ketone.

this is the mass spec from the nist website for methyl isobutyl keytone.

this is the mass spec of the unknown the professor gave us from the website. This is the IR I collected.

120 43 100 80 C 60 D 40 58 20 85 2 ㄡ 9 667 72 7983 68 0 40 80 100 20 m/z