Heavy metals from industrial wastewater can accumulate in shellfish or fish and enter the food chain at concentrations millions of times higher than that in the water supply. Methods for the detection of heavy-metal ions are mostly expensive and not suitable for portable, on-site applications.
Liang Feng, Yafeng Guan, and co-workers, Dalian Institute of Chemical Physics, China, have found a way to immobilize commercially available heavy-metal-ion indicators. Organically modified siloxanes were chosen as the host materials and by adjusting the addition time of the indicators, leaching and blooming could be avoided.
The resulting sensor array could discriminate between eight heavy-metal-ions at standard wastewater-discharge concentrations. Color-difference maps provided a fingerprint with which to identify the metals and no misclassifications were found in the 45 trials performed.
The authors expect that further development will lead to a functional handheld device for on-site detection.
- Discrimination of Trace Heavy-Metal Ions by Filtration on Sol–Gel Membrane Arrays
L. Feng, Y. Zhang, L. Wen, L. Chen, Z. Shen, Y. Guan,
Chem. Eur. J. 2011.