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Dear Dan, I've done a fair bit of AAS and ICP-AES analyzes of coppers and copper based alloys in both coins and artifacts. Obviously there is a small amount of damage necessitated by sampling the coins - using a 0.5 to 0.8 mm diameter drill and drilling into the edge of the coin - but both techniques have good sensitivities using a 20mg sample weight. Generally, I've used a variety of commercially available SRM's to monitor precision and accuracy whilst using a matrix matched cocktail of certified commercial ICP single element standard solutions to calibrate the instrument. Results are usually better than the manufacturer estimates - but much is down to pipetting skills! The SRM's I use include Bundesanstalt fur materialprufung (BAM) Nr. 211 - this is a bronze (10.6% Sn), but has a number of useful minor and trace elements (Pb, Zn, Ni, Fe, Ag, Sb, P, As, S, Bi, Mn, Cd and Se). The same people also do certified coppers (Nr. 365 and 366) and a variety of other alloys. Regards, Dr. Matthew Ponting Department of Archaeology University of Nottingham University Park NOTTINGHAM NG7 2RD Office: (0115) 951 4815 Fax: (0115) 951 4812 http://www.nottingham.ac.uk/archaeology/research/