Our mass spectrometer delivers very low backgrounds (<0.2 cps). Coupled with a good sensitivity of 3.5 x 10⁸ cps ppm-1 (Ce), instrument detection limits are in the single to double digit ppq range for most elements of geochemical interest. The challenge in the laboratory is to translate these theoretical detection limits into practical detection limits by minimizing blanks. Paradoxically, the biggest cost of solution analysis is not mass spectrometer time but is a reflection of the effort required to minimize the blank.

Steve Eggins (at the Australian National University) and later Alan Greig (at the University of Queensland) demonstrated that high quality data can be obtained with careful solution ICP-MS analyses. We follow these methods and continually strive to improve on them.

The table below lists our long-term reproducibilities for three commonly analyzed USGS rock standards calibrated against W-2. These repeat analyses yield relative standard deviations of better than 2% for more than 30 elements, in many cases (e.g. REE) even better than 1%.