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

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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/
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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)

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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)

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Purpose

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

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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

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Test Kits
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General Characteristics
Test Kit Concentration Intervals Number of Reagents Test Time (min)
BVC-100 10, 25, 50, 100, 500 2 13
ECO-W100 25, 50, 100, 150, 200, 300, 500, 750 4 35
Hach 10, 30, 50, 70, 300, 500 5 40
LaMotte 4, 6, 8, 10, 12, 14, 16, 18, 20, 30, 40, 50, 60, 70, 80, 100, 140, 160 3 16
Merck 10, 25, 50, 100, 500 2 32
Quick II 1, 2, 2.5, 3, 4, 5, 6, 7, 10, 12, 14, 20, 30, gt30, gt40, gt60, gt80, gt100 3 16
Trace Detect Continuous 3 10
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General Characteristics
Test Kit Sample size (ml) Unit Price ( US dollars) Samples per kit Cost / test
BVC-100 10 30.00 100 0.30
ECO-W100 10 36.00 100 0.36
Hach 50 106.00 100 1.06
LaMotte 250 153.00 50 3.06
Merck 10 69.60 100 0.70
Quick II 100 219.99 50 4.40
Trace Detect 50 12,500.00 5000 2.50
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• Methods
• Selection of Field Test Kits
• Inexpensive
• Commercially available
• Portable
• Multiple lot numbers
• Seven field kits

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• 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

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Methods Chemistry of Field Test Kits
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• Methods
• Reference Method
• US EPA approved
• EPA Method 7060A (Graphite Furnace Atomic
  Absorbance)

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• 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

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Laboratory Performance Results
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• 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)

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

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Operator bias
Test kit Operator 1 Slope (intercept) Correlation coefficient
BVC-100 Operator 4 0.87 (0.0) 0.897
ECO-W100 Operator 4 0.99 (-1.6) 0.905
Hach Operator 2 0.84 (2.44) 0.829
LaMotte Operator 3 1.0 (0.77) 0.890
Merck Operator 3 0.47 (4.9) 0.689
Quick II Operator 2 0.90 (1.0) 0.873
Significant to the 0.01 alpha level.
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Operator Ease of Use
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• 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

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• 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

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• Contact Information

http//www.hbg.psu.edu/etc/