Marchitto 2006 Precise Sector Field ICP-MS Foram Multi-Elemental Ratios Marchitto, T.M. Marchitto, T.M. earth science/paleoclimate/paleocean (Global>LATITUDE >LONGITUDE ) Inductively coupled plasma mass spectrometry (ICP-MS) holds two main advantages over other techniques for the measurement of foraminiferal elemental ratios: (1) numerous trace metals may be precisely and simultaneously measured, and (2) smaller samples may theoretically be used. Methods are presented for the precise determination of Mg/Ca, Sr/Ca, Cd/Ca, Zn/Ca, Li/Ca, U/Ca, Mn/Ca, and Fe/Ca by sector field ICP-MS. Analytical precision is largely independent of sample size over the range of ~5 to 125 ug CaCO3, eliminating the need for narrow target dilutions. Long-term 1 sigma precisions are as follows: Mg/Ca = 0.54%, Sr/Ca = 0.57%, Cd/Ca = 1.8%, Zn/Ca = 3.2%, Li/Ca = 0.88%, U/Ca = 1.9%, Mn/Ca = 0.97%, and Fe/Ca = 1.4%. For Mg/Ca, actual foraminiferal samples appear to give reliable results below 10 ug CaCO3 (postcleaning mass). STUDY NOTES: 46Ca/43Ca count ratios were blank-corrected and normalized to bring mean of standards in each run to 2.6. Metal/Ca deviations were calculated as (Me/Ca)meas/(Me/Ca)known - 1. Outliers are 2s relative to linear equations through all data. Final sample masses were calculated from measured [Ca]. VARIABLES AND UNITS: 46Ca/43Ca count ratios (%) Ca concentrations (mM) Metal/Ca deviations from known (ratio-1) G. bulloides Mg/Ca (mmol/mol) sample size as mass CaCO3 (ug) PRECISION: Mg/Ca: 0.54% Sr/Ca: 0.57% Cd/Ca: 1.8% Zn/Ca: 3.2% Li/Ca: 0.88% U/Ca: 1.9% Mn/Ca: 0.97% NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Marchitto, T.M. 2007-01-01 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/5947 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.txt English https://www.ncdc.noaa.gov/paleo/study/5947 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/marchitto2006/marchitto2006.txt Marchitto, T.M. 2007. Precise multielemental ratios in small foraminiferal samples determined by sector field ICP-MS. Geochem. Geophys. Geosyst., 7, Q05P13. doi:10.1029/2005GC001018. START YEAR: -50 cal yr BP * END YEAR: -60 cal yr BP -180 -90 180 90