Portable system based on microsensors for environmental monitoring applications

摘要

A versatile and portable system based on microsensors for measuring simultaneously pH, oxidation-reduction potential (ORP), conductivity and temperature in samples of environmental interest has been assembled and evaluated. An ion selective field effect transistor (ISFET) for pH measurements and platinum microelectrodes for ORP and conductivity measurements are used within the system. The multi-parametric system includes a commercial temperature sensor and the circuitry for each one of the mentioned sensors which can be exchanged or replaced. A commercial module with a USB interface is used for the acquisition and control of data from a laptop PC. Validation of the whole system has been carried out with standard solutions, providing high device-to-device reproducibility and stable response of all sensors during at least 24 h measured in a standard solution. Analysis of waste water samples with the portable system has been carried out to test its feasibility in environmental applications. Data have been compared with commercial electrodes.