Table 3.

IDMS sample data and measurement results for the molality of ²³³Pa in the S solution

Sample ID	233Pa S solution* aliquots (g)	U reverse-spike aliquots (g)	Measured isotope ratio n(238U)/n(233U)	Molality of 233Pa (pmol g−1)
233Pa 1A	2.0640 ± 0.0010	0.3613 ± 0.0010	132.21 ± 0.30	0.14680 ± 0.00057
233Pa 1B	2.0586 ± 0.0010	0.7128 ± 0.0010	261.35 ± 0.59	0.14690 ± 0.00048
233Pa 2A	1.7827 ± 0.0010	0.5993 ± 0.0010	254.01 ± 0.58	0.14676 ± 0.00049
233Pa 2B	2.3084 ± 0.0010	0.6633 ± 0.0010	216.67 ± 0.49	0.14705 ± 0.00049
233Pa 3A	1.6769 ± 0.0010	0.3569 ± 0.0010	160.64 ± 0.37	0.14692 ± 0.00057
233Pa 3B	2.5439 ± 0.0010	0.4086 ± 0.0010	121.31 ± 0.28	0.14683 ± 0.00055
233Pa 4A	1.9842 ± 0.0010	0.6033 ± 0.0010	229.45 ± 0.51	0.14693 ± 0.00049
233Pa 4B	2.2204 ± 0.0010	0.4804 ± 0.0010	163.19 ± 0.37	0.14700 ± 0.00052

The quantity measured by IDMS was the molality of ²³³U in the decayed S solution (pmol ²³³U g⁻¹). Corrections for solution evaporation and undecayed ²³³Pa were applied to the IDMS data to yield molality of ²³³Pa at the reference time of 27 June 2017 22:50 UTC. Uncertainties are expanded uncertainties (U=ku_c) with a coverage factor (k) of 2. All mass values are corrected for air buoyancy

^*Correction factors for ²³³Pa sample aliquots were applied to compensate for relatively small evaporative losses (from 0.3 to 1.0%) that occurred over the interval between dispensing and aliquoting for IDMS (298 d). These factors were calculated as the quotient of the solution mass at the time of initial dispensing and the solution mass immediately prior to aliquoting for IDMS analyses