Impact of matrix effects on the accurate measurement of Li isotope ratios by inductively coupled plasma mass spectrometry (MC-ICP-MS) under "cold" plasma conditions

被引:63
作者
Bryant, CJ [1 ]
McCulloch, MT [1 ]
Bennett, VC [1 ]
机构
[1] Australian Natl Univ, Res Sch Earth Sci, Canberra, ACT 0200, Australia
关键词
D O I
10.1039/b212083f
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Lithium isotopic measurements by MC-ICP-MS using "cold'' plasma conditions are characterised by fewer baseline interferences and improved reproducibility as compared with conventional hot plasma techniques. The 2sigma precisions for 1200 W, 800 W and 680 W are conservatively estimated as 1.1parts per thousand, 0.7parts per thousand and 0.5parts per thousand. However, matrix effects are most significant at the coldest plasma temperatures, with deviations of >0.5parts per thousand delta(7)Li being observed at 680 W for 100 ng g(-1) Li solutions containing greater than or equal to 500 ng g(-1) Na. However, no matrix effects were detected at 800 W for solutions containing up to 5000 ng g(-1) Na. Lithium isotopic measurements under all conditions are strongly sensitive to variations in acid concentration, requiring precise matrix matching between samples and standards. Self-induced Li matrix effects are not evident for Li concentrations below 120 ng g(-1), however blank corrections are necessary. The isotopic ratios of Li separated from seawater at 680 W (delta(7)Li = +30.7 +/- 0.4parts per thousand) and 800 W (+30.4 +/- 0.9) are subtly lower than those obtained for 1200 W (delta(7)Li = +32.0 +/- 0.2), although all lie within error given the reported reproducibility and all are within the range of previously published analyses. With minimisation of matrix induced fractionation, the precision and accuracy achievable at 680 W and 800 W equals or surpasses that previously reported for TIMS and conventional hot plasma ICP-MS.
引用
收藏
页码:734 / 737
页数:4
相关论文
共 22 条
[1]  
BOUMAN C, 2002, VM GOLDSCHM C GEOCH
[2]   VARIATION OF LITHIUM ISOTOPE COMPOSITION IN THE MARINE-ENVIRONMENT - A PRELIMINARY-REPORT [J].
CHAN, LH ;
EDMOND, JM .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1988, 52 (06) :1711-1717
[3]   Measurement of lithium isotope ratios by inductively coupled plasma mass spectrometry: Application to geological materials [J].
Gregoire, DC ;
Acheson, BM ;
Taylor, RP .
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, 1996, 11 (09) :765-772
[4]   High-precision measurement of calcium isotopes in carbonates and related materials by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) [J].
Halicz, L ;
Galy, A ;
Belshaw, NS ;
O'Nions, RK .
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, 1999, 14 (12) :1835-1838
[5]   Lithium isotope composition of Quaternary and Tertiary biogene carbonates and a global lithium isotope balance [J].
Hoefs, J ;
Sywall, M .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1997, 61 (13) :2679-2690
[6]   Lithium and its isotopes in major world rivers: Implications for weathering and the oceanic budget [J].
Huh, Y ;
Chan, LH ;
Zhang, L ;
Edmond, JM .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1998, 62 (12) :2039-2051
[7]   Lithium isotopes as a probe of weathering processes: Orinoco River [J].
Huh, Y ;
Chan, LH ;
Edmond, JM .
EARTH AND PLANETARY SCIENCE LETTERS, 2001, 194 (1-2) :189-199
[8]   The lithium isotope composition of international rock standards [J].
James, RH ;
Palmer, MR .
CHEMICAL GEOLOGY, 2000, 166 (3-4) :319-326
[9]   Precise measurement of Li isotopes in planktonic foraminiferal tests by quadrupole ICPMS [J].
Kosler, J ;
Kucera, M ;
Sylvester, P .
CHEMICAL GEOLOGY, 2001, 181 (1-4) :169-179
[10]   High-yield lithium separation and the precise isotopic analysis for natural rock and aqueous samples [J].
Moriguti, T ;
Nakamura, E .
CHEMICAL GEOLOGY, 1998, 145 (1-2) :91-104