Determination of B/Ca of natural carbonates by HR‐ICP‐MS. (2nd April 2014)

• Record Type: Journal Article
• Authors: Misra, Sambuddha; Greaves, Mervyn; Owen, Robert; Kerr, Joanna; Elmore, Aurora C.; Elderfield, Henry
• Is Part Of: Geochemistry, geophysics, geosystems. Volume 15:Number 4(2014:Apr.)
• Page Start: 1617
• Page End: 1628
• Publication Date: 2014-04-02
• Subjects: Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 550.5
• DOI: 10.1002/2013GC005049
• Languages: English
• ISSNs: 1525-2027

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>We report a new method for HR‐ICP‐MS based accurate and precise B/Ca determination from low mass natural carbonates (≤5 µg CaCO₃), utilizing a mixed acid matrix (0.1 M HNO₃ and 0.3 M HF) and accurate matrix matching technique. Our procedural B/Ca blank of 2.0 ± 1.0 µmol/mol, internal precision ≤1.0%, average within run external precision ≤4.0% (2σ), and rapid sample analysis (60 samples/day) make the method well suited for routine measurements. Established methods of B/Ca determination require ≥65 µg CaCO₃ to achieve a comparable external precision of 3.5% (2σ). We report a B/Ca detection limit of 2 µmol/mol compared to ≥10 µmol/mol for previous methods, a fivefold improvement. The method presented here can determine a wide range of B/Ca (9.0–250 µmol/mol) in mass limited samples with considerable tolerance for matrix matching efficiency (≤±30%). The long‐term reproducibility of B/Ca measured on Cambridge in‐house consistency standards containing &lt;20, ∼85, and ∼200 µmol/mol of B/Ca are ±3.7% (2σ, n = 100), ±3.9% (2σ, <italic>n</italic> = 150), and ±3.2% (2 s, <italic>n</italic> =180), respectively. A host of other trace element to Ca ratios can also be determined at comparable external precision from samples containing ≤5 µg CaCO₃. This method is suitable for trace element analysis of single foraminifera shells.</p> </abstract>