Prepositions are words that show the relationship between a noun or pronoun and another word in the sentence. They usually indicate location, direction, time, or manner. Examples of prepositions include:
* on
* in
* at
* to
* from
* with
Reflexive pronouns are used when the subject and object of a verb refer to the same person or thing. They always end in "-self" or "-selves". Examples of reflexive pronouns include:
* myself
* yourself
* himself
* herself
* itself
* ourselves
* yourselves
* themselves
Therefore, "itself" is not a preposition, but a reflexive pronoun.