If i smoked marijuana once and had a hair follicle test 109 days out will i pass? i would estimate that i smoked about 1/2 a joint

Unlikely: Thc is stored in fat cells which serve as a reservoir and release it slowly into the bloodstream and from there into hair follicles. For a long time user, the "reservoir" can be quite full and so may feed follicles at 6 mo and longer. The new hair growing out takes some follicle thc with it as new thc is being fed in. From 1/2 joint very little will be stored.