4. Conclusions
A new SPME coating based on cavitand 1 was developed and tested for the selective and ultrasensitive determination of BTEX in air. With respect to previously developed QxCav SPME fiber, the receptor conformational rigidity and the reduction of the cavity opening allowed to obtain higher enrichment factors, very low detection limits and increased selectivity toward benzene. The main features of the developed material are excellent thermal stability, a very good repeatability and a very good sensitivity with responses up to more than forty-fold higher than those obtained using commercial devices.
Taking into account that this new SPME fiber is insensitive to the most common interfering agents present in air, i.e. aliphatic hydrocarbons and water it can be exploited for the development of portable devices in which cavitand 1 is used as trapping material for the on-line and in-situ environmental monitoring of BTEX.
In addition, BTEX adsorption can be performed in a very short time, thus allowing the use of the proposed SPME fiber for the assessment of short-term exposure in workers.