Loading Procedures

Whole Rock Nd Isotope Loading

1. Generate a parafilm dam on the filament.
2. Add 10 uL of 2N HNO₃ acid to the sample beaker, making sure the acid is applied directly to the bead of H₃PO₄ remaining after sample dry down.
3. Add ~40 ng of Nd from the beaker to the filament, with the filament current turned all the way down. If your sample dissolution aimed for 200 ng of Nd, this should be a 2 uL load.
4. While the filament is still cold, load 2 uL of Ta₂O₅-H₃PO₄ emitter solution directly onto sample bead on the filament. Make sure to thoroughly shake the beaker containing the Ta₂O₅-H₃PO₄ emitter solution prior to pipetting it out, and only pipette from the top of the solution in the beaker.
5. Dry down at 1 A for 5 minutes. If 5 minutes have passed and the sample-emitter solution bead has not dried down completely, simply wait until it has.
6. Slowly increase filament current to 1.8 A. Hold at this level for at least 2 minutes. The bead color for unknown samples will likely turn to brown at this point, rather than the clear bead loaded onto the filament.
7. Slowly increase the filament current until filament has a faint glow. This will likely occur between 2.2-2.5 A. Once a faint orange glow is achieved, hold at this point for 5 seconds.
8. Slowly decrease the filament current to 0.

Sr Loading

1. Add 2 uL of HCl to sample beaker, making sure the acid is applied directly to the bead of H₃PO₄ remaining after dry down.
2. Add 2 uL of TaCl₅ to sample beaker, making sure that the solution is added directly to the bead of H₃PO₄ remaining after dry down.
3. Place filament into loading bench.
4. Turn Filament to 1.5 A.
5. With new pipette for each sample, gently stir the solution, and draw in 2 uL of the solution.
6. In small drops slowly drip the solution onto the center of the filament until all of the solution has been added. Allow the solution to dry for ~2 mins at 1.5 A. The solution should be completely dry or near completely dry.
7. Slowly increase the current of the filament as you increase the current on the filament the sample should turn to a dark brown color and let off a small amount of smoke.
8. Continue to slowly increase the current of the filament to between 2.5 A and 3.0 A. The filament will start to glow allow the filament to glow for ~2-3 seconds
9. Decrease the filament current to 0 A and remove the filament and place into the correct spot of the turret, and in the sample catalog move the sample from ready samples to loading turret into the correct location.