TY - JOUR
T1 - Determination of Ultralow Level 129I/127I in Natural Samples by Separation of Microgram Carrier Free Iodine and Accelerator Mass Spectrometry Detection
AU - Hou, Xiaolin
AU - Zhou, Weijian
AU - Chen, Ning
AU - Zhang, Luyuan
AU - Liu, Qi
AU - Luo, Maoyi
AU - Fan, Yukun
AU - Liang, Wangguo
AU - Fu, Yunchong
PY - 2010
Y1 - 2010
N2 - Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level 129I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced 129I. In this work, we present a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass spectrometry was used to measure ultralow level 129I in micrograms of iodine target. The recovery of iodine in the entire separation procedure is higher than 80% and 65% for solid and water samples, respectively. One microgram iodine in the target (AgI−AgCl) can produce a stable 127I signal for AMS measurement of 129I/127I, and a detection limit of this method for 129I is calculated to be 105 atoms. This will allow us to accurately determine 129I in prenuclear geological samples of low iodine concentration with 129I/127I of 10−12, such as loess, soil, coral, rock, sediment, and groundwater. Some samples with low iodine content have been successfully analyzed, and the lowest value of the 129I/127I ratio of 2 × 10−11 was observed in 23.5 and 63.5 m loess samples collected in the Loess Plateau, China. The developed method sheds light on a wide application in earth science
AB - Separation of carrier free iodine from low iodine level samples and accurate measurement of ultralow level 129I in micrograms of iodine target are essential but a bottleneck in geological dating of terrestrial system and tracer research using naturally produced 129I. In this work, we present a carrier free method using coprecipitation of AgI with AgCl for preparing micrograms of iodine target, associated with combustion using a tube furnace for separating iodine from solid samples and anion exchange chromatography for preconcentrating iodine from a large volume of water. An accelerator mass spectrometry was used to measure ultralow level 129I in micrograms of iodine target. The recovery of iodine in the entire separation procedure is higher than 80% and 65% for solid and water samples, respectively. One microgram iodine in the target (AgI−AgCl) can produce a stable 127I signal for AMS measurement of 129I/127I, and a detection limit of this method for 129I is calculated to be 105 atoms. This will allow us to accurately determine 129I in prenuclear geological samples of low iodine concentration with 129I/127I of 10−12, such as loess, soil, coral, rock, sediment, and groundwater. Some samples with low iodine content have been successfully analyzed, and the lowest value of the 129I/127I ratio of 2 × 10−11 was observed in 23.5 and 63.5 m loess samples collected in the Loess Plateau, China. The developed method sheds light on a wide application in earth science
KW - Radiation research and nuclear technologies
KW - Radio ecology and tracers
KW - Strålingsforskning og nukleare teknologier
KW - Radioøkologi og sporstoffer
U2 - 10.1021/ac101558k
DO - 10.1021/ac101558k
M3 - Journal article
C2 - 20735008
SN - 0003-2700
VL - 82
SP - 7713
EP - 7721
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 18
ER -