Microextraction Tech

Figure 1. Structure of polythiophene Despite their potential, the applicability of polythiophene (PT) based coatings in solid phase microextraction (SPME) is limited by their low thermal stability. In fact, PT coatings are not suitable for temperatures higher than 200 ºC and therefore they are not applicable for the extraction of a wide variety of semi-volatiles analytes. Moreover, the use of low desorption temperatures usually causes carry-over problems as the analytes are not effectively desorbed between two consecutive extractions. The improvement of the thermal stability of PT can be achieved by two different strategies which consist in the addition to the polymerization mixture of dopants with negatively charged groups. In the first approach, special reagents (like surfactants) are directly added to the polymerization mixture while in the second approach special monomers containing negative charged moieties are used to produce the so-called self-doped polymers. The l...