Surface acoustic wave (SAW) microsensor array for measuring VOCs in drinking water

Area of Science:

• Environmental Science
• Analytical Chemistry
• Sensor Technology

Background:

• Volatile organic chemicals (VOCs) in drinking water pose health risks, including cancer and organ damage.
• Current analytical methods for VOC detection are costly and complex, limiting routine water quality assessment.
• There is a need for accessible, on-site methods for VOC screening in water supplies.

Purpose of the Study:

• To develop and evaluate a cost-effective instrument for the field analysis of VOCs in drinking water.
• To assess the instrument's sensitivity and accuracy compared to reference laboratory methods.
• To determine the potential of this technology for routine water quality monitoring.

Main Methods:

• Development of a field instrument utilizing an array of six polymer-coated surface-acoustic-wave microsensors.
• Optimization of a purge-trap preconcentration system for VOC analysis.
• Calibration of the instrument using a test set of common VOCs across relevant concentration ranges.
• Comparison of instrument results with those from a reference laboratory.
• Application of artificial neural networks (ANNs) for data analysis and classification of VOC mixtures.

Main Results:

• The instrument demonstrated adequate sensitivity for 19 of 21 regulated VOCs within a 10-minute analysis cycle.
• Artificial neural networks achieved high classification rates: 99% for individual vapors, 90% for binary mixtures, and 80% for ternary mixtures.
• The developed instrument provides a cost-effective alternative for on-site VOC evaluation.
• Results showed good agreement with reference laboratory findings.

Conclusions:

• The developed surface-acoustic-wave microsensor array instrument shows significant potential for effective field-screening of VOCs in drinking water.
• This technology addresses the need for improved, accessible, and rapid on-site water quality monitoring.
• The system offers a viable solution for enhancing the routine characterization of VOC contaminants in water supplies.