New Calcium Carbonate Nano‐particulate Pressed Powder Pellet (NFHS‐2‐NP) for LA‐ICP‐OES, LA‐(MC)‐ICP‐MS and µXRF

Abstract

A new matrix‐matched reference material has been developed – NFHS‐2‐NP (NIOZ Foraminifera House Standard‐2‐Nano‐Pellet) – with element mass fractions, and isotope ratios resembling that of natural foraminiferal calcium carbonate. A 180–355 µm size fraction of planktic foraminifera was milled to nano‐particles and pressed to pellets. We report reference and information values for mass fractions of forty‐six elements measured by six laboratories as well as for 87 Sr/ 86 Sr (three laboratories), δ 13 C, δ 18 O (five laboratories) and 206,207,208 Pb/ 204 Pb isotope ratios (one laboratory) determined by ICP‐MS, ICP‐OES, MC‐ICP‐MS, isotope ratio mass spectrometry, WD‐XRF and TIMS. Inter‐ and intra‐pellet elemental homogeneity was tested using multiple LA‐ICP‐MS analyses in two laboratories applying spot sizes of 60 and 70 µm. The LA‐ICP‐MS results for most of the elements relevant as proxies for palaeoclimate research show RSD values < 3%, demonstrating a satisfactory homogeneous composition. Homogeneity of 87 Sr/ 86 Sr ratios of the pellet was verified by repeated LA‐MC‐ICP‐MS by two laboratories. Information values are reported for Pb isotope ratios and δ 13 C, δ 18 O values. The homogeneity for these isotope systems remains to be tested by LA‐MC‐ICP‐MS and secondary‐ion mass spectrometry. Overall, our results confirm the suitability of NFHS‐2‐NP for calibration or monitoring the quality of in situ geochemical techniques.