1. The Determination of 224 Ra, 226 Ra, & 228 Ra in Water Samples Michael Fern Eichrom Technologies, Inc.

2. Background EPA monitoring of radium in water in US Ra-224 found in drinking water in New Jersey Need for faster method to measure Ra-224 ASTM + US Geological Survey

3. 12 Load sample in 0.095M HNO 3 Rinse 0.095M HNO 3 1 2 3 0.35M HNO 3 3 3 Ln Resin 1 2 0.5-2 L acidified sample Ba-133 BaSO 4 ppt Conversion to BaCO 3 {hold for ~30 hrs.} 0.095M HNO 3  -ray measurement Ba-133 228 Ra via 228 Ac {proportional or HPGe counter} 226 Ra via Rn emanation 223,224 Ra via  -spectrometry Original Method – Eichrom RAW01 (Burnett, et al., 1995)

4. 228 Ra Results Burnett, et al. 1995 SampleExpected Result Bq/L Experimental Result Bq/L EMSL Ra/H 2 O 17 July, 1992 0.618 ± 0.1220.651 ± 0.026 EMSL 228 Ra Standard2.19 ± 0.082.24 ± 0.05 Decontamination Experiment 1.10 ± 0.041.17 ± 0.02 EMSL Performance Eval. 19 April, 1994 0.744 ± 0.1850.799 ± 0.044

5. Limitations of Original Method α-emitters determined by Rn emanation: too long Need fast method to measure 224 Ra (t 1/2 = 3.66 days) 30 hour ingrowth for 228 Ac Conversion of SO 4 2- to CO 3 2- is tedious

6. New Approach - RAW03 Load sample in 0.095M HNO 3 Rinse 0.095M HNO 3 1 2 3 0.35M HNO 3 Ln Resin 1 3 21 3 2 228 Ra via 228 Ac {proportional or HPGe counter} 224, 226 Ra via  -spectrometry 1 2 3 2 1 3 Cation Resin Ln Resin 1 2 3 Load sample at pH 2 (0.5 – 1 L) Rinse 50 mL 0.1M HNO 3 50 mL 8M HNO 3 Evaporate and re-dissolve in 0.095M HNO 3 To waste

7. Advantages of New Method No need for 228 Ac ingrowth Eliminate dangerous and inconsistent carbonate conversion Rapid measurement of α-emitting isotopes Same day measurement of 224 Ra

8. 226 Ra % Recoveries-0.5L DI Water Eichrom data

9. 226 Ra Alpha Spectrum

10. 226 Ra, 224 Ra, and Daughters 226 Ra 222 Rn 224 Ra 218 Po 220 Rn

11. 226 Ra % Recoveries in Tap water Eichrom data

12. 226 Ra in EPA Sample Sept.18, 1998 Eichrom data

13. 226 Ra in NJ Sample Eichrom data

14. 226 Ra in Georgia Inst. Of Tech. Sample# S8933 Eichrom data

15. 226 Ra in Georgia Inst. Of Tech. Sample# WS 14776 Eichrom data

16. 226 Ra Results Herbert, USEPA 2002 SampleChemical recovery (Ba-133 ) Spiked pCi/L (mBq/L) Found pCi/L (mBq/L) A92.8%1.16 (42.9) 1.22 (45.1) B87.1%5.80 (215) 5.73 (212) C84.3%11.6 (429) 11.7 (433)

17. 228 Ra Results Herbert, USEPA 2002 SampleChemical recovery (Ba-133) Spiked pCi/L (mBq/L) Found pCi/L (mBq/L) A92.8%32.8 (1210) 32.0 (1180) B87.1%10.9 (403) 11.9 (440) C84.3%4.37 (162) 4.54 (168)

18. Ca and Mg Interference in 500 mL Samples Eichrom data

19. Ca Interference in 100 mL of Sample Eichrom data

20. Detection Limits – 226 Ra US EPA Requires: 37 mBq/L

21. Summary <37 mBq/L detection limits achievable Eliminates inconsistent carbonate conversion Faster measurement of 224 Ra High amounts of Ca and Mg interferences handled well with 100 mL samples Acceptable 226 Ra and 228 Ra recoveries

22. Special thanks to: Anil Thakkar, Eichrom Technologies David McCurdy & Ann Cleveland, ASTM Dr. B. Parsa, New Jersey department of health, NJ Dr. B. Kahn, Georgia Institute of Technology, GA References: Burnett, W.C., Cable, P.H., & Moser, R.; Determination of Ra-228 in Natural Waters Using Extraction Chromatography, Radioactivity & Radiochemistry, vol. 6, no. 3 (1995) Herbert, V., USEPA NAREL, Single Operator Test Report, ASTM Test Method: Ra in Water; presented at RRMC, Knoxville, TN 11/2002.