High through-put groundwater arsenic speciation analysis using an automated flow analyzer

Area of Science:

• Environmental Science
• Analytical Chemistry
• Public Health

Background:

• Geogenic arsenic in groundwater poses a global health risk, with limited data hindering identification of contaminated domestic wells.
• Lack of low-cost, rapid analytical methods impedes effective arsenic monitoring and risk assessment.

Purpose of the Study:

• To develop a high-throughput, reliable, and portable automated analyzer for on-site determination of inorganic arsenic species (arsenite and arsenate) and phosphate in groundwater.
• To provide a cost-effective solution for rapid arsenic screening in domestic wells, crucial for public health protection.

Main Methods:

• Development and optimization of a portable automated analyzer based on molybdenum blue spectrophotometry for arsenite (As(III)), arsenate (As(V)), and phosphate determination.
• System validation through assessment of sample throughput, operational costs, sensitivity, linearity, and precision.

Main Results:

• The developed system achieves high sample throughput (4.8 samples/h) and low operational costs (0.3 CNY/sample).
• Demonstrates appropriate sensitivity (detection limits 4.7-8.3 µg/L), excellent linearity (R² > 0.9996), and high precision (RSDs 2.8-3.5%).
• Successfully applied to analyze arsenic speciation in five groundwater samples from Yinchuan Plain, China.

Conclusions:

• The portable automated analyzer is a promising novel method for rapid, on-site screening of arsenic in groundwater.
• This technology can significantly aid in identifying non-compliant domestic wells and protecting public health globally.