New nanostructure of polydimethylsiloxane coating as a solid-phase microextraction fiber: Application to analysis of BTEX in aquatic environmental samples

â¿¢Polydimethylsiloxane sol gel was electrospun on a SPME fiber.â¿¢Nanostructures of polydimethylsiloxane were formed on the fiber.â¿¢The home-made fiber was stable in high temperatures of GC.â¿¢The coated fiber was used in trace analysis of BTEX.

Electrospinning technique was used to convert polydimethyl siloxane (PDMS) sol-gel solution to a new nanostructure on a stainless steel wire. The surface morphology of the fiber was observed by scanning electron microscopy (SEM). It showed a diameter range of 30⿿60 nm for PDMS nanoparticles with a homogeneous and porous surface structure. The applicability of this coating was assessed for the headspace SPME (HS-SPME) of benzene, toluene, ethylbenzene and xylenes (BTEX) from water samples followed by gas chromatography⿿mass spectrometry. The important parameters affecting extraction efficiency such as extraction time and temperature, desorption conditions, agitation rate and ionic strength were investigated and optimized.Under the optimized conditions, LODs and LOQs of 0.3⿿5 μgL⿿1 and 1⿿10 μgL⿿1 were obtained, respectively. The method showed linearity in the broad range of 1⿿5000 μgL⿿1 with correlation coefficient of >0.99. Inter-day and intra-day precisions of the developed method ranged from 2.43% to 6.54% and from 5.24% to 13.73%, respectively. The thermal stability of the fiber was investigated on stainless steel wire. It was found to be durable at 260 °C for more than 360 min. Furthermore, the proposed method was successfully applied for quantification of BTEX in real water samples.