Daan: Suspect that Auger analysis (This is pronounced like the name of the famous basketball star who was tried for murder....OJ) may be the best approach. The problem with Auger is that it may be too sensitive, as it picks up every atom on the surface, and there is a trace of almost every element on most surfaces, so to compensate for this, I recommend you doing Auger on both the suspect area, as well as a "clean" area, and comparing the results. This is typically done in labs dedicated to this, and the charge is per hour, with a minimum charge. I can tell you where to get this done on the West Coast of the US, but cannot assist for Europe. Hope this helps. Rudy Sedlak RD Chemical Company --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------