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Analytical Capabilities of the BU-TIMS Facility Nd isotopes We are capable of measuring the Nd isotopic compositions of a variety of rocks, minerals, fossil material, waters and soils. Nd isotopes are run as the oxide on a single Rhenium filament using a slurry of Tantalum oxide in phosphroic acid as an oxygen source during ionization (download manuscript outlining our techniques). This technique allows very small aliquots of Nd to be accurately measured. By maintaining a > 2V 142Nd beam for > 200 cycles on 4 ng loads, internal precisions of <10 ppm (2-sigma) on the 143Nd/144Nd ratio are consistently achieved (see below). Long term external reproducibility of our in house Ames Nd isotopic standard on 4 ng loads has been maintained at 18.0 ppm (2-sigma) on all samples run since march 2007. Within barrel external precision on 4 ng loads is better than 10 ppm (2-sigma), comparable to the precision on several hundred nanogram loads run as the metal. Within Barrel External Precision on 4ng Ames NdO loads
Sr Isotopes We are capable of measuring the Sr isotopic compositions of a variety of rocks, minerals, fossil material, waters and soils. Strontium isotope ratios are measured on single Re filaments with a tantalum oxide emitter solution in a static routine acounting for both potential Rb interefence and Sr fractionation. We currently focussing on improving the external reproducibility of Sr anayses in the lab. External reproducibilty of 4 ng loads of the NBS 987 Sr standard is 32 ppm (2-sigma). In addition the triton is capable of producing 10 ppm (2-sigma) precision on loads >100 ng. External reproducibility of 4ng loads of NBS 987 Sr Standard
Pb isotopes Measurement of Pb isotopes from whole rock samples is a recent addition to the capabilites of the lab. Pb isotopes are run on single Rhenium filaments using silica gel-phosphoric acid emitter solution. Our currently small database of measurements of the NBS-981 Pb isotopic standard indicates our capabilty of measuring precise Pb istopic ratios in static mode (see below). External Reproducibility of NBS 981 Pb Std for various load sizes
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