A new investigation in the early 1980s, by a team under Thomas Cahill at the University of California, Davis, using Particle-Induced X-ray Emission (PIXE) found that only trace amounts (< 0.0062% by weight) of titanium appeared to be present in the ink, which should have been too little for some of McCrone's analyses to detect. The Cahill team acknowledged, however, that titanium was the only element within their technique's measurement capability which was significantly more concentrated in the ink than on the bare parchment (other elements such as iron and zinc were found concentrated in some inked samples, but only a minority). One member of the team, Gregory Möller, also analyzed loose particles retrieved from the split down the middle of the map by a different method, finding that most of them were rich in titanium (though a few black particles were rich in chromium and iron). Because they were the first to apply PIXE to ink analysis, nobody at the time could explain the difference between the Cahill and McCrone figures. Attempting to reconcile the conflicting results, the Cahill team suggested that the high concentrations found by McCrone were due to a combination of contamination from modern dust, and poor sample selection (i.e. choosing contaminant particles like those in the split); however, they also chose not to publish or publicise Möller's loose particle study. The accumulation of large amounts of PIXE data from other laboratories around the world in the ensuing decades was sufficient by 2008 to show that the Cahill figures for all elements in the inks of the map and its companion documents are at least a thousand times too small, so the discrepancy is due to a problem with their work.