  Inductively coupled plasma mass spectroscopy is a powerful technique for
measuring trace levels of radioactive contaminants, specifically Th and U, in
materials for use in construction of low-background rare-event detectors such
as double beta decay and dark matter detectors. I describe here a technique for
measuring Th and U contamination in copper using direct acid digestion and
dilution, without further chemical processing, achieving results comparable to
previous work which utilized more complex chemical pre-concentration
techniques. A convenient research-oriented analysis environment is described as
well. Results are presented for measurements of three samples from the
production line of electrolytically-purified, LME (London Metal Exchange) grade
A, NA-ESN Aurubis copper. Purified samples showed levels consistent with zero
contamination for both elements, while weak but inconclusive indications of
contamination were present for the un-purified anode copper. The best limits
achieved are near $1\cdot 10^{-12}$~g/g (95% CL) for both Th and U measured for
copper from the cathode of the purification process.
