Test for arsenic speciation in waters based on a paper-based analytical device with scanometric detection

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Arsenic contamination in water poses significant health risks.
• Accurate and affordable arsenic speciation methods are crucial for public health and environmental monitoring.
• Existing methods can be complex, expensive, or lack sensitivity for regulatory compliance.

Purpose of the Study:

• To develop a rapid, simple, and affordable method for arsenic speciation analysis using a paper-based analytical device (PAD).
• To achieve detection limits for arsenic below established regulatory standards.
• To validate the method for determining different arsenic species in water samples.

Main Methods:

• In situ arsine generation followed by headspace transfer.
• Reaction of arsine with silver nitrate on a PAD for colorimetric detection.
• Image processing for data analysis and quantification.
• Optimization of experimental parameters including sensor composition and hydride generation conditions.

Main Results:

• Achieved limits of detection (LOD) and quantification (LOQ) of 1.1 and 3.6 ng/mL, respectively.
• LOD is significantly lower than WHO and US EPA maximum contaminant levels for arsenic in drinking water.
• Demonstrated good repeatability (7.1% RSD) and successful validation with certified reference material.
• Applied successfully for the determination of As(III), As(V), and total inorganic arsenic in various water samples.

Conclusions:

• The developed PAD method offers a sensitive, rapid, and cost-effective approach for arsenic speciation analysis.
• The method surpasses the performance of some commercial test kits and meets stringent regulatory requirements.
• This technology is suitable for screening total arsenic in water, with potential applications in environmental monitoring and public health surveillance.