Tetsuya Yokoyama & Eizo Nakamura (2004) Precise analysis of the 228Ra/226Ra isotope ratio for short-lived U-series disequilibria in natural samples by total evaporation thermal ionization mass spectrometry (TE-TIMS), Journal of Analytical Atomic Spectrometry, 19, 717-727, doi:10.1039/B400829D. < 20191011113816-801170 > pub

Map on Earth or stone. Places and analyses are shown.

  • abstract:

    We report a new analytical technique for precise and accurate determination of the 228Ra/226Ra ratio by total evaporation thermal ionization mass spectrometry (TE-TIMS). An improved chromatographic separation method employing a new tandem column technique that enables high yield and high purity of Ra is also described. Repeated analysis of Ra standard solution (228Ra/226Ra = 1.1) yielded an analytical reproducibility for 228Ra/226Ra ranging from 0.2% to 0.9% (2σ) for 170 to 2 fg of Ra. Reproducibility was strongly controlled by counting statistics of 226Ra+ and 228Ra+ ion beam intensities collected by an ion counting detector, implying that in-run precision for Ra isotope analysis of our method can be evaluated using a counting statistics law. Determination of 226Ra abundances in silicate rock samples were examined by isotope dilution TE-TIMS, and reproducibility was 0.3% (2σ) for JR-2 (226Ra = 3700 fg g−1) and 0.6% (2σ) for JB-2 (226Ra = 81 fg g−1); the reproducibility of these measurements are 2–3 times better than previously published conventional TIMS procedures. The 226Ra/228Ra ratio in natural samples can be also measured with an analytical uncertainty of ∼1% (2σ). The accuracy of our method was confirmed by measuring (226Ra/230Th) and (228Ra/232Th) ratios for JR-2, a sample old enough (1 Ma) to be in 230Th–226Ra and 232Th–228Ra radioactive equilibria. Our method is especially effective for samples with a very low abundance of Ra.

  • doi: 10.1039/B400829D
  • modified at yesterday, 05:06
1: JB2-1 2: JB2-2


(a) U-Series_procedures of Yokoyama et al. (1999, 2001, 2003) on TIMS Thermo-Fisher MAT262
1: CA076


(a) U-Series_procedures of Yokoyama et al. (1999, 2001, 2003) on TIMS Thermo-Fisher MAT262
Img 8252@58452bedef311c2498f872f thumb JB-2 < 20130416090250-887738 >pub
  • classification: volcanic:basaltic
  • physical-form: powder
  • status: (unknown)
  • description: Geological Survey of Japan silicate reference material - tholeiitic basalt from Izu-Oshima, Japan (erupted in 1950 AD); split 7, position 19
  • modified at 2020-06-16
R0010219 thumb CA076 < 20100416092338636.hkitagawa >pub
  • classification: volcanic:basaltic
  • physical-form: powder
  • status: (unknown)
  • age (a): 21 (0)
  • description: Mt. Cameroon alkali basalt, erupted in 1999 AD
  • modified at 2020-04-20
name box-type global-id
binder of Precise analysis of the 228Ra/226Ra isotope ratio for short-lived U-series disequilibria in natural samples by total evaporation thermal ionization mass spectrometry (TE-TIMS) pub container 20191011113841-987060
name device size global-id
ref-gl-jb2 pub Q-ICPMS Agilent 7500cs 55 20170302124544-731488
JB-2_Cl-F pub 761 COMPACT IC 2 20190515103147-299945
JB-2 pub ICPMS Yokogawa PMS2000 22 20191008091433-571271
JB-2_FeO pub 1 20191009141755-701622
JB-2_TiO2 pub HR-ICPMS Finningan, Element 1 20191008134323-345539
JB-2_W-Sb-Mo pub ICPMS Yokogawa PMS2000 3 20191008113359-987281
JB-2_U pub ICPMS Thermo-Fisher Neptune 2 20191023140518-782251
JB-2_Hf pub MC-ICP-MS Finnigan, Neptune 2 20191023150858-360045
JB-2_Li pub ICPMS Yokogawa PMS2000 1 20191015113423-995945
JB-2_Th pub ICPMS Thermo-Fisher Neptune 2 20191023140820-456541
JB-2_Bi-Tl-In-Cd pub Q-ICPMS Agilent 7500cs 4 20191002151232-133506
JB-2_d66Zn pub ICPMS Thermo-Fisher Neptune 1 20191003102338-443368
JB-2_d56Fe pub ICPMS Thermo-Fisher Neptune 1 20191003113551-268022
JB-2_Ge-As-Se-Te pub Q-ICPMS Agilent 7500cs 4 20191004111800-764807
JB-2_Ta-Hf-Nb-Zr pub ICPMS Yokogawa PMS2000 4 20191008105612-696377
JB-2_S pub HR-ICPMS Finningan, Element 1 20191008141043-335650
JB-2_Cr-Ni-Cu-Zn pub HR-ICPMS Finningan, Element 4 20191009100320-804729
JB-2_B pub ICPMS Yokogawa PMS2000 1 20191007144129-710421
JB-2 pub MC-ICP-MS Finnigan, Neptune 1 20191219094725-536598
JB-2_S (Max, 2012) pub ICPMS Thermo-Fisher Neptune 1 20191223152828-773022
JB-2_226Ra pub MC-ICP-MS Finnigan, Neptune 1 20200131112956-636986
JB-2_Li pub TIMS Thermo-Fisher MAT261 2 20200210103937-712454
JB-2 pub ICPMS Yokogawa PMS2000 1 20200213153336-912830
JB-2 pub ICPMS Yokogawa PMS2000 2 20200213153348-280479
JB-2 pub TIMS Thermo-Fisher MAT261 1 20200213153411-590596
JB-2 pub ICPMS Yokogawa PMS2000 1 20200213153400-458802
JB-2 pub TIMS Thermo-Fisher MAT261 2 20200213153422-381614
JB-2 pub TIMS Thermo-Fisher MAT261 4 20200213153431-920662
JB-2 pub XRF PANalytical PW2400 3 20200219095011-457226
JB-2_B (Nakamura,1992) pub TIMS Thermo-Fisher MAT261 2 20200221121528-403757
CA076_Ra pub TIMS Thermo-Fisher MAT262 5 20191011135840-810655
JB2-1_B pub TIMS Thermo-Fisher MAT261 2 20191011091956-857703
JB2-2_B pub TIMS Thermo-Fisher MAT261 2 20191011092231-398963
JB2-1_Pb pub TIMS Thermo-Fisher MAT261 3 20191011093459-383699
JB2-2_Pb pub TIMS Thermo-Fisher MAT261 3 20191011093639-992779
JB2-2_Ra pub TIMS Thermo-Fisher MAT262 4 20191011135602-253524
JB2-1_Ra pub TIMS Thermo-Fisher MAT262 4 20191011135228-878050
JB2-2_Sm-Nd pub TIMS Thermo-Fisher MAT261 4 20191011102056-733424
JB2-1_Rb-Sr pub TIMS Thermo-Fisher MAT261 4 20191011101511-959093
JB2-1_Sm-Nd pub TIMS Thermo-Fisher MAT261 4 20191011101646-745665
JB2-2_Li pub TIMS Thermo-Fisher MAT261 2 20191011095851-447069
JB2-2_Rb-Sr pub TIMS Thermo-Fisher MAT261 4 20191011101815-177013
JB2-1_Li pub TIMS Thermo-Fisher MAT261 2 20191011095740-854602
name spots global-id
caption ID rowname stone
Table 2 Repeated analysis of Ra abundance in GSJ standard by TE-TIMS pub 20191011143002-687320 Ra (Yokoyama et al., 2004) 2
Table 3 Repeated analysis of 226Ra/228 Ra ratio in natural sample pub 20191011143345-502579 Ra226zRa228 (Yokoyama et al., 2004) 1
manual
  • name
  • Tetsuya Yokoyama
  • Eizo Nakamura