A probe for a system for determining the chemical signature of a pharmaceutical compound. The device comprises a video camera which is directable towards the welding zone for recording the welding process in the form of video signals transmitted, via an image processing unit, to a video display unit, which the user is able to view and which is placed in or on the inside of the shielding element. The ionic liquids can be produced via formation of at least one intermediate carboxylated ionic liquid, and thereafter subjecting the intermediate carboxylated ionic liquid to at least one anion exchange process.