In this work, the development of a pretreatment system to assist in-situ surface plasmon sensor-based measurement of arsenic in water is described. The system uses a primary filter made of non-activated cotton fibers for particulate matter and chemical retention agents and a secondary filter for retention of mercury, lead, and other heavy metals without alteration of the arsenic concentration in the collected water samples to be sensed. This secondary filter was made with amino-functionalized carbon nanotubes.
The results of the operational assessment of this filter show a retention efficiency of 98% for suspended solids, 96% for mercury ions, and 2% for arsenic, a remarkable improvement toward the accurate detection and quantification of arsenic in contaminated waters.