“…Further experimental details were reported earlier. [10][11][12] The Faraday detectors of a double-focusing multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS, Nu Plasma™, NU Instruments, Wrexham, Wales, U.K.) measured the abundance of 235 U and 238 U in the ablated particle cloud. Before switching to LA, the MC-ICP-MS was tuned for sensitivity and stability of U signals in solution mode employing an aqueous 30 ng L À1 U calibration solution having natural U isotopic composition.…”