how do i validate the extract function found a delimiter or not?

i'm testing a very  inconsistent  database from an integration   and i'm trying  to get a especific fields if it is there but  the thing is that the  end limiter could be different in too many ways   and this throws me an error that broke my program i tried to many times of not breaking  it  like using index() but  nothing helps  also i tried to   use another function to obtain the values like  the func wherecontains() as a starindex   whitin a mid() function but i didn't fiind the way  of making it work