Clemson University TigerPrints Chemical and Biomolecular Graduate Research Research and Innovation Month Symposium

Spring 2015 Alternative Sample Loading Preparation for Thermal Ionization Mass Spectrometry Scott M. Husson Clemson University

Brian Powell Clemson University

Glenn Fugate Savannah River National Laboratory

David Locklair Clemson University

Joseph Mannion Clemson University

Follow this and additional works at: https://tigerprints.clemson.edu/chembio_grs Part of the Chemical Engineering Commons

Recommended Citation Husson, Scott M.; Powell, Brian; Fugate, Glenn; Locklair, David; and Mannion, Joseph, "Alternative Sample Loading Preparation for Thermal Ionization Mass Spectrometry" (2015). Chemical and Biomolecular Graduate Research Symposium. 9. https://tigerprints.clemson.edu/chembio_grs/9

This Poster is brought to you for free and open access by the Research and Innovation Month at TigerPrints. It has been accepted for inclusion in Chemical and Biomolecular Graduate Research Symposium by an authorized administrator of TigerPrints. For more information, please contact [email protected]. Plutonium Isotopic Analysis: Alternative Sample Loading for Thermal Ionization MS Scott M. Husson1, Brian Powell1, Glenn Fugate2, David Locklair1, & Joseph Mannion1 Clemson University1 and SRNL2

Project Relevance Alternative Sample Loading Method: Rhenium Oxidation: Potential Source of Sample Loss and Unexplained Performance Variation  Thermal Ionization Mass Spectrometry (TIMS) analysis is known as the “gold Thin-Film Loading standard” in isotopic ratio measurements for plutonium. Figure 9: SEM images of  Isotopic distribution of plutonium indicates the “grade” of material and can be Goal: Simplify sample loading by pre-coating the rhenium filaments with anion- rhenium oxide crystal used to determine the source ; a common measurement being the 239Pu/ 240Pu exchange material, eliminate/reduce sample loss, and improve overall efficiency. growth on a filament ratio. surface.  TIMS is used widely for nuclear forensics and nuclear safeguards analyses of a b cc Sample loaded on Coated filament long-lived isotopes; due partly to ultra-low detection limits offered by TIMS rhenium ribbon loaded into TIMS pre-coated with Figure 8: Tapping mode AFM images of rhenium (on order of ~femtograms for Pu) and unparalleled accuracy. Sample Purification system and nd anion-exchange analyzed wafer: (left) No degassing, (2 ) post-degassing. ~ 2 - 3 Weeks polymer. ~4 Hour analysis 15 minutes - 4 Hours for single sample 5% 95% 150% 150% Contact Time Cured at 60 °C, 45 h What is Thermal Ionization Mass Spec.? General Mass Spec. Design Production of a Thin-Film Ion Point Source Figure 10: EBSD Magnetic Field mapping of Generator =100 µm; ReO3-IPFZ; Step=1 µm; Grid400x300 rhenium surface Bead loading provides an “ion-point source” greatly improving ion transportation High m/z Low m/z into the mass spec region of the instrument relative to more dispersed ion sources.

Ion Source Detector Capillary small-spot TEA/Chloroform functionalization Hydrophobic Bulk Film

Submerge Plutonium Uptake studies and TIMS analysis Thermo Scientrific Triton Plus™ Multicollector TIMS in Water c a Ionization occurs at or near Polymer Film Substrate Hydrophilic Examination of actinide extraction TIMS analysis of reference the surface of a hot Functionalized Spot Cross-linked kinetics (batch) samples polymer thin-film (~2000 °C) rhenium filament. Heat Quaternary amine functional site Figure 3: Small spots Material loaded Filament type Total Counts Comments modified with tri-ethyl Pu reference (242Pu and 239Pu) 1 (NBL CRM 128) amine produce “hydrophilic 11 pg Bead loaded on 411884 Completed 4 hour Poly(vinylbenzyl Diazabicylco[2.2.2] 0.9 carbonized analysis time chloride) octane wells” aiding in sample filament 0.8 Tri-ethyl amine loading and concentration. 10 pg Direct load on 12524 Tuned with 500 (TEA) 0.7 degassed filament cps on Pu and Current Sample Loading Process: gone after 15 min Loading 0.6 10 pg Direct load on thin 276 Tuned with 400 Figure 1: Synthetic methods developed to produce Condition: Stability and diffusion testing of polymer film cps on Pu and chemically stable films with small functionalized spots. 0.5 8M Nitric filament gone after 12 min Bead Loading 9M HCl 10 pg Direct load on thin 1200 Tuned with 400 2000 extractant coated ribbons 0.4 9M HCl polymer film cps on Pu and Film Original film Thickness after 9 M HCl 0.3 filament gone after 14 min Treatment Anion-Exchange 40 μm Bead Glued 1500 Description thickness exposure 10 pg Direct load on thin 5719 Tuned with 450 0.2 polymer film cps on Pu and Resin Bead onto Rhenium 10% 5% CL Aged for 1 month in filament gone after 20 min 0.1 PVBC/TEA 184.3 ± 3.7 nm 180.3 ± 8.0 nm atmosphere with no 10 pg Direct load on thin 4717 Tuned with 500 Filament 1000 5% Fraction of Final Equilibrium State (~40 μm) modified acid treatment 0 polymer film cps on Pu and 3% 5% CL 0 2 4 6 8 10 12 14 16 filament gone after 19 min 500 PVBC/TEA 178.1 ± 2.9 nm 174.9 ± 2.0 nm 9 M HCl – 1 h Duration of Pu242 Exposure [min] 10 pg Direct load on thin 13027 Tuned with 300

2% modified polymer film cps on Pu and Film Thickness [nm]Thickness Film Filament with 1% 5% CL filament gone after 22 min Sample Purification 0 PVBC/TEA 177.2 ± 4.7 nm 176.6 ± 6.7 nm 9 M HCl – 17 h 10 pg Direct load on thin 11308 Tuned with 500 Purified bead loaded into modified Figure 11: Batch uptake kinetics of tri-ethyl amine 0 100 200 300 400 polymer film cps on Pu and Sample TIMS system and 5% CL treated poly(vinylbenzyl chloride) films cast on filament gone after 23 min ~ 2 - 3 Weeks Withdrawal Speed [mm/min] PVBC/TEA 183.2 ± 5.9 nm 178.4 ± 5.5 nm 9 M HCl – 3 day analyzed modified silicon. Aqueous Pu242 concentrations were Table 2: TIMS analysis of 180 nm films cast Figure 2: A wide range of film thicknesses are attainable Table 1: Stability analysis of films cast on silicon. Film on flat Re ribbons performed at SRNL. ~10 minutes by expert; measured with ICP-MS. 4 - 8 Hours ~4 Hour analysis through modification of dip-coating conditions. thicknesses measured with multi-angle ellipsometry. Films contained low level of crosslinking Years of experience to master Contact Time for single and small functionalized spot. sample High carbon loading from thick continuous films led to filament breakages; small Bead loading offers the lowest detection limit of any current TIMS sample anion-exchange polymer spots are being investigated as an alternative approach. loading method by: Future Work  Maintaining a reducing atmosphere within the TIMS  Producing plutonium –carbide species  Directly study effects of rhenium oxidation on TIMS performance.  Providing an ion point source  Load anion-exchange polymer with dissolved rhenium salts through anion- Figure 4: Small anion exchange spots are produced by applying a small drop of polymer solution to the substrate with a needle. exchange before plutonium loading; Cons of Bead Loading: attempt to increase Re/Pu contact.  Bead loading is difficult, time-consuming, and expensive. Figures 5, 6, 7:  Study effects of rhenium filament geometry  SEM and 3D SEM and test novel geometries such as the SRNL reports that approximately 20% sample loss occurs from bead-loading. images of small  It is estimated that approximately 95% of the sample could remain in the anion-exchange “extreme V” and surface holes or pitting. graphitic skeleton left by the bead. polymer spots.

Acknowledgements: We are grateful for the financial support of this work by the National Nuclear Security Administration NA-221 Office of Proliferation Detection under Award No. DE-NA0001735.