This study presents U–Pb isotopic results from the mineral zircon measured by nanosecond laser ablation coupled to either a time-of-flight inductively coupled plasma mass spectrometer (ICP-MS), a quadrupole ICP-MS or both via a split stream arrangement. Results show both ICP-MS types produce similar levels of precision and accuracy for most U–Pb ages in the mineral zircon. The time-of-flight ICP-MS however shows slight non-linearity at high detector counts (> 7000 for ²³⁸U) producing a bias in zircon U–Pb ages from published values outside analytical uncertainty. Use of ²³⁵U instead of ²³⁸U is shown to resolve the inaccuracy in the U–Pb age at the expense of analytical precision due to lower abundance of ²³⁵U. Trace element concentrations also measured along with U–Pb isotope data in zircon show the time-of-flight ICP-MS to provide similar accuracy and precision as the quadrupole ICP-MS, except for isotopes in regions around high intensity major element peaks (e.g. Zr) where accuracy and levels of detection of the time-of-flight ICP-MS are matrix dependent relative to the quadrupole ICP-MS. A comparison is made between the analytical capabilities of the time-of-flight ICP-MS and the quadrupole ICP-MS highlighting some advantages and disadvantages of the time-of-flight technology for zircon U–Pb geochronology.

Item Type:	Refereed Article
Keywords:	zircon, LA-ICPMS, time of flight MS, split stream LA-ICPMS
Research Division:	Earth Sciences
Research Group:	Geology
Research Field:	Geochronology
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the earth sciences
UTAS Author:	Thompson, JM (Mr Jay Thompson)
UTAS Author:	Danyushevsky, LV (Professor Leonid Danyushevsky)
ID Code:	144704
Year Published:	2020
Funding Support:	Australian Research Council (IH130200004)
Web of Science® Times Cited:	3
Deposited By:	CODES ARC
Deposited On:	2021-06-06
Last Modified:	2021-07-28
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