Evaluation of Several Field Test Kits for Determining Concentrations of Arsenic in Drinking Water

1. Evaluation of Several Field Test Kits for Determining Concentrations of Arsenic in Drinking Water J. Mitchell Spear, You “Mark” Zhou Charles A. Cole and Yuefeng F. Xie Environmental Programs Penn State Harrisburg Penn State Harrisburg US EPA Small Public Water Systems Technology Assistance Center http://www.hbg.psu.edu/etc/

2. Background • Regulation • Published arsenic rule (January 22, 2001) • Lowers Maximum Contaminant Level from 50 ug/L to 10 ug/L Arsenic • Compliance date (January 23, 2006) • Water Utilities affected • Approximately 4000 in US • 97 % serving less than 10,000 people • Removal Options • Best Available Technologies (BAT) • Small System Compliance Technologies (SSCT)

3. Background • Point-Of-Use (POU) Options • Activated Alumina • Ion Exchange • Iron Based Sorption Media • Reverse Osmosis • Monitoring • Graphite Furnace Atomic Absorption (GFAA) • Inductively Coupled Plasma Emissions Spectrophotometry (ICP-AES) • Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) • Hydride Generation Atomic Adsorption (HGAA)

4. Purpose • Evaluate several commercially available field test kits and determine reliability and applicability to water utilities currently conducting noncompliance arsenic analyses.

5. Methods • Test Kits • selection • chemistry • reference method • Laboratory performance • accuracy • precision • Matrix interference and field performance • Antimony and sulfide • Linearity on field sample • Operator performance • operator bias • “ease of use”

6. Test Kits

7. General Characteristics

8. General Characteristics

9. Methods • Selection of Field Test Kits • Inexpensive • Commercially available • Portable • Multiple lot numbers • Seven field kits

10. Methods • Chemistry of Field Test Kits • Arsine gas generation • (similar to SM 3114) Hydride generation • Semi-qualitative • Anodic Stripping Voltammetry (ASV) • (similar to SM 3130) • Qualitative

11. Methods Chemistry of Field Test Kits

12. Methods • Reference Method • US EPA approved • EPA Method 7060A (Graphite Furnace Atomic Absorbance)

13. Laboratory Performance • Accuracy and Precision • Traditionally (Method Detection Limit) • Accuracy (percent recovery) % Recovery = ConcTestKit / ConcGFAA * 100 • Precision (standard deviation) • Arsenic III, V, III + V • Concentration • Replicates

14. Laboratory Performance Results

16. Matrix interference and Field Performance • Antimony levels • (0, 0.25, 1.0 and 5.0 mg/L) • Sulfide levels • (0, 0.5, 5.0 and 10.0 mg/L) • Linearity • (5, 10, 25, 50, 75 µg/L)

23. Operator Performance • Operator Bias • Schock and George (1993) • “Ease of Use” • Instructions • Chemical additions • Equipment • Result interpretation • Scale • 1 - most difficult • 10 - easiest

24. Operator bias * Significant to the 0.01 alpha level.

25. Operator “Ease of Use”

26. Conclusions • Three test kits performed well • Two field test kits met all criteria (easy to use, accurate, precise, inexpensive, no operator bias) • These two could be used by water operators for noncompliance testing

27. Acknowledgements • US EPA Small Public Water Systems Technology Assistance Center Grant • Peng Chen, Mukesh Pratap, Brian Montalbano, and Paul Deardorff for analytical analyses • Trace Detect for loan of there instrumentation

28. Contact Information http://www.hbg.psu.edu/etc/