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The Determination of 226 Ra in Water Samples

eichrom. TECHNOLOGIES INC. The Determination of 226 Ra in Water Samples. Anil H . Thakkar Eichrom Technologies, Inc. eichrom. TECHNOLOGIES INC. Objective. To design a procedure for radium in water samples using Eichrom’s cation exchange resin and Ln Resin. eichrom.

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The Determination of 226 Ra in Water Samples

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  1. eichrom TECHNOLOGIES INC The Determination of 226Ra in Water Samples AnilH. Thakkar Eichrom Technologies, Inc.

  2. eichrom TECHNOLOGIES INC Objective • To design a procedure for radium in water samples using Eichrom’s cation exchange resin and Ln Resin.

  3. eichrom TECHNOLOGIES INC Current Procedure Used • Barium sulfate precipitation • Conversion to BaCO3- tedious and time consuming

  4. eichrom TECHNOLOGIES INC Current Procedure Used • Sample + Ba carrier + Ba-133 + Conc.H2SO4_+ Heat BaSO4 • Precipitate allowed to settle for several hours or overnight • Precipitate collected and converted to BaCO3

  5. eichrom TECHNOLOGIES INC New Approach Water samples Cation exchange resin column Eichrom Ln Resin column

  6. eichrom TECHNOLOGIES INC Preparation of Water Samples • 0.5 L / 1.0 L water samples, acidified to pH 2 • Add 133Ba as a tracer

  7. eichrom TECHNOLOGIES INC Eichrom Cation Exchange Column • Load solution: 0.5 L/ 1.0 L of sample • Rinse with 50 mL of 0.1M HNO3 • Strip Ra and Ba with 50 mL of 8M HNO3

  8. eichrom TECHNOLOGIES INC Preparation of Load Solution for Ln Resin Column • Evaporate eluent from cation exchange column to dryness • Dissolve residue in 10 ml of 0.095M HNO3 acid • Load on Eichrom Ln Resin column

  9. eichrom TECHNOLOGIES INC Ln Resin Column Separation (1) Load: 10 mL of mL 0.095M HNO3, Collect 1) and (2) for Ba & 226Ra (2) Rinse: 15 mL of 0.095M HNO3 (3) Strip: 10 mL of 0.35M HNO3 collect (3) for 228Ac

  10. eichrom TECHNOLOGIES INC 226Ra Via Alpha Spectrometry • Evaporate 226Ra/133Ba fraction to 10 mL volume • Add 3 mL of 40% sodium sulfate, 4 drops of 1:1 acetic acid. Swirl • Add 0.2 mL of seeding suspension. Mix • Place tubes in cold water bath for 30 minutes • Filter on 0.1 micron filters, count via alpha spectrometry

  11. eichrom TECHNOLOGIES INC 133Ba Via Gamma Counter • Count 133Ba tracer yield via gamma spectrometry

  12. eichrom TECHNOLOGIES INC 228Ac Via Gas-Flow Proportional Counter • Add 50 micrograms of cerium carrier • Add 1.0 mL of HF • Filter on 0.1 micron filters • Measure for beta radiation

  13. eichrom TECHNOLOGIES INC 226Ra % Recoveries-0.5L DI Water

  14. eichrom TECHNOLOGIES INC 226Ra Alpha Spectrum

  15. eichrom TECHNOLOGIES INC 133Ba Gamma Spectrum

  16. eichrom TECHNOLOGIES INC 226Ra, 224Ra, and Daughters 224Ra 226 Ra 220Rn 218Po 222Rn

  17. eichrom TECHNOLOGIES INC 226Ra % Recoveries in Tap water

  18. eichrom TECHNOLOGIES INC 226Ra in EPA SampleSept.18, 1998

  19. eichrom TECHNOLOGIES INC Summary • Cation exchange resin option: • provides a good replacement for the time consuming BaSO4 precipitation steps • it eliminates inconsistent metathesis steps • reduces usage of chemicals/reagents • provides consistency and saves time • Acceptable 226Ra recoveries

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