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

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 mu m 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 Sr-87/Sr-86 (three laboratories), delta C-13, delta O-18 (five laboratories) and Pb-206,Pb-207,Pb-208/Pb-204 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 mu m. 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 Sr-87/Sr-86 ratios of the pellet was verified by repeated LA-MC-ICP-MS by two laboratories. Information values are reported for Pb isotope ratios and delta C-13, delta O-18 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.

Automated summary

A new matrix-matched reference material (NFHS-2-NP) has been developed and tested by multiple laboratories, demonstrating satisfactory homogeneity and suitability for calibration and quality monitoring of geochemical techniques.