ABSTRACT
The last years have been characterized by an increasing number of pollutants released in the environment, especially by human activities in water. For this reason there is a great need for disposable systems for screening and real time monitoring, possibly “on-site”, of the several contaminants as cheaply as possible. A wide number of analytical methods, based on the most commonly employed physico-chemical techniques for the detection of several pollutants (mainly HPLC, GC, MS or various combinations of them), in environmental matrices are available (Barcelò 1993). These traditional techniques are extremely powerful in terms of sensitivity and selectivity, but, apart from economic consideration, they also present some drawbacks, because of the need for qualifi ed staff and to carry out extensive pretreatment processes on the sample to be assayed. More important, these techniques cannot be applied on the spot, thus making the continuous monitoring of a risky area virtually impossible. These reasons have led to the development of alternative analytical devices and methods to be applied for screening and monitoring of various contaminants in environmental matrices, possibly minimizing the pretreatment of samples, reducing the cost and time of analysis. Nonetheless, an ideal screening method should satisfy the basic requirement of ensuring the detection of the different contaminants without the risk of false negatives, and with a percentage of false positive as low as possible.
