A universal collisional activation ion trap comprises an ion trapping means containing a bath gas and having connected thereto a noise signal generator (4). A method of operating a universal collisional activation ion trap comprises the steps of: providing an ion trapping means (1-3); introducing into the ion trapping means a bath gas; and generating a noise signal within the ion trapping means; introducing into the ion trapping means a substance that, when acted upon by the noise signal, undergoes collisional activation to form product ions.