Interlaboratory comparison of magnesium isotopic compositions of 12 felsic to ultramafic igneous rock standards analyzed by MC‐ICPMS
Interlaboratory comparison of magnesium isotopic compositions of 12 felsic to ultramafic igneous rock standards analyzed by MC‐ICPMS
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DOI：
10.1002/2015gc005939
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发表时间：
2015-09
期刊：
影响因子：
3.7
通讯作者：
F. Teng;Q. Yin;C. Ullmann;R. Chakrabarti;Philip A. E. Pogge von Strandmann;Wei Yang;Wangye Li;S. Ke;F. Sedaghatpour;J. Wimpenny;A. Meixner;R. Romer;U. Wiechert;S. Jacobsen
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作者：
F. Teng;Q. Yin;C. Ullmann;R. Chakrabarti;Philip A. E. Pogge von Strandmann;Wei Yang;Wangye Li;S. Ke;F. Sedaghatpour;J. Wimpenny;A. Meixner;R. Romer;U. Wiechert;S. Jacobsen
为了评估天然材料高精度稳定镁同位素分析的实验室间质量偏差，在五个实验室中使用三种类型的多接收器电感耦合等离子体质谱仪（MC‐ICPMS）分析了一套硅酸盐标准品，其组成从长英质到超镁铁。在引用的不确定度范围内，所有实验室的镁同位素组成对大多数岩石是一致的，但对一些镁铁质样品来说差异很大（26 Mg/24 Mg高达0.3‰，不确定度>4倍）。实验室间的质量偏差与基质元素/镁的比例无关，产生它的机制是不确定的，但很可能是由色谱柱化学引起的。我们的研究结果表明，需要不同的基质标准来校准柱化学的效率，并且在处理具有复杂基质的样品时应谨慎。应使用具有与样品匹配的基质元素的良好校准的标准品，以减少实验室间质量偏倚。
To evaluate the interlaboratory mass bias for high‐precision stable Mg isotopic analysis of natural materials, a suite of silicate standards ranging in composition from felsic to ultramafic were analyzed in five laboratories by using three types of multicollector inductively coupled plasma mass spectrometer (MC‐ICPMS). Magnesium isotopic compositions from all labs are in agreement for most rocks within quoted uncertainties but are significantly (up to 0.3‰ in 26Mg/24Mg, >4 times of uncertainties) different for some mafic samples. The interlaboratory mass bias does not correlate with matrix element/Mg ratios, and the mechanism for producing it is uncertain but very likely arises from column chemistry. Our results suggest that standards with different matrices are needed to calibrate the efficiency of column chemistry and caution should be taken when dealing with samples with complicated matrices. Well‐calibrated standards with matrix elements matching samples should be used to reduce the interlaboratory mass bias.