Combined oxygen and silicon isotope analysis of biogenic silica

Citations Over TimeTop 1% of 2008 papers

Abstract

Abstract There is increasing interest in the use of biogenic silica O and Si isotope ratios to understand climate and environmental processes. Virtually all of the fairly substantial body of literature deals with either oxygen or silicon. This is partly because measurement of oxygen isotope composition is done using either vacuum dehydration, isotope exchange or stepped fluorination techniques, while increasingly researchers are turning to multicollector inductively coupled plasma mass spectrometry (MC‐ICP‐MS) for Si isotope analysis, even though Si isotope analysis can be done using fluorination methods used for the oxygen isotope measurements. Here we describe a procedure for simultaneous determination of isotopic abundances of oxygen and silicon from the same aliquot of biogenic silica. Pure silica is dissociated into O and Si compounds using a fluorination technique, in which reaction with bromine pentafluoride (BrF 5 ) produces oxygen (O 2 , subsequently converted to CO 2 ), silicon tetrafluoride (SiF 4 ) and other fluorine by‐products (e.g. BrF 3 ). These compounds are cryogenically separated using cold traps. Yields for oxygen and silicon recovery are 70–80% for biogenic silica depending on the nature of the hydrous layer and 97–99% for pure quartz. Reproducibility of the oxygen isotopic composition is ca. 0.3‰ and silicon between 0.06–0.12‰. © Natural Environment Research Council (NERC) copyright 2008. Reproduced with the permission of NERC. Published by John Wiley & Sons, Ltd.

Related Papers

• → Fractionation of silicon isotopes during biogenic silica dissolution(2009)160 cited
• → A silicon isotopic perspective on the contribution of diagenesis to the sedimentary silicon budget in the Southern Ocean(2022)21 cited
• → The silicon isotope record of early silica diagenesis(2015)70 cited
• → Mechanisms controlling silicon isotope distribution in the Eastern Equatorial Pacific(2011)37 cited
• Isotopic approaches in the silicon cycle: the Southern Ocean case study(2010)