title: Determination of lead isotopes in a new Greenland deep ice core at the sub-picogram per gram level by thermal ionization mass spectrometry using an improved decontamination method.
abstract: An improved decontamination method and ultraclean analytical procedures have been developed to minimize Pb contamination of processed glacial ice cores and to achieve reliable determination of Pb isotopes in North Greenland Eemian Ice Drilling (NEEM) deep ice core sections with concentrations at the sub-picogram per gram level. A PL-7 (Fuso Chemical) silica-gel activator has replaced the previously used colloidal silica activator produced by Merck and has been shown to provide sufficiently enhanced ion beam intensity for Pb isotope analysis for a few tens of picograms of Pb. Considering the quantities of Pb contained in the NEEM Greenland ice core and a sample weight of 10 g used for the analysis, the blank contribution from the sample treatment was observed to be negligible. The decontamination and analysis of the artificial ice cores and selected NEEM Greenland ice core sections confirmed the cleanliness and effectiveness of the overall analytical process.
authors.affiliation: Department of Ocean Sciences, Inha University,100 Inha-ro, Nam-gu, Incheon 402-751, Republic of Korea; Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Changhee
authors.initials: C
authors.lastname: Han
authors.affiliation: Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U1987, Perth 6845, Western Australia, Australia.
authors.forename: Laurie J
authors.initials: LJ
authors.lastname: Burn-Nunes
authors.affiliation: Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Khanghyun
authors.initials: K
authors.lastname: Lee
authors.affiliation: Department of Ocean Sciences, Inha University,100 Inha-ro, Nam-gu, Incheon 402-751, Republic of Korea; Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Chaewon
authors.initials: C
authors.lastname: Chang
authors.affiliation: Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Jung-Ho
authors.initials: JH
authors.lastname: Kang
authors.affiliation: Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Yeongcheol
authors.initials: Y
authors.lastname: Han
authors.affiliation: Korea Polar Research Institute, Songdomirearo 26, Yeonsu-gu, Incheon 406-840, Republic of Korea.
authors.forename: Soon Do
authors.initials: SD
authors.lastname: Hur
authors.affiliation: Department of Ocean Sciences, Inha University,100 Inha-ro, Nam-gu, Incheon 402-751, Republic of Korea. Electronic address: smhong@inha.ac.kr.
authors.forename: Sungmin
authors.initials: S
authors.lastname: Hong
keywords: Greenland deep ice core; Improved decontamination procedure; Lead isotopes; Silica-gel activator; TIMS