P1.9.27 Off-flavors monitoring in raw and treated water by means of an electronic tongue system
- 14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
- P1.9 Technology and Application
- G. Braga, F. Fonseca - Escola Politécnica da Universidade de São Paulo (Brazil), L. Paterno - Instituto de Química da Universidade de Brasília, Campus Universitário Darcy Ribeiro (Brazil)
- 1243 - 1245
An electronic tongue (ET) system based on non-specific chemical sensors was used to detect and quantify offflavors compounds, namely geosmin (GSM) and 2-methylisoborneol (MIB), in raw and treated water samples collected from the Guarapiranga reservoir (Sao Paulo-Brazil). Four sets of samples were evaluated with the ET system: sets 1 and 2 were composed by raw and treated waters, respectively, and measured as collected whereas sets 3 and 4 were composed by raw and treated samples plus addition of known amounts of MIB and GSM. The electrical fingerprints (capacitance) generated by the ET for the different samples were processed by principal component analysis. The ET easily performed samples` discrimination while providing distinct and well-separated clusters for each type of sample. Furthermore, scores after repeated samples` replicas were close grouped which indicates that the ET`s response is reproducible. The ET`s sensitivity is also high and the presence of both GSM and MIB could be detected at concentrations as low as 20 ng.L-1. The results confirmed the analysis performed independently by GC/MS spectrometry and by a human panel.