Sorbent coated glass wool fabric as a thin film microextraction device

A new approach for thin film microextraction (TFME) with mixed-phase sorptive coating is presented. Carboxen/polydimethylsiloxane (CAR/PDMS) and polydimethylsiloxane/divinylbenzene (PDMS/DVB) TFME samplers were prepared using spin coating and glass wool fabric mesh as substrate. The samplers were easily tailored in size and shape by cutting tools. Good durability and flat-shape stability were observed during extraction, stirring in water, and thermal desorption. The latter characteristic obviates the need for an extra framed holder for rapid TFME and makes the samplers more robust and easier to deploy. The samplers combine the advantages of adsorptive solid-phase microextraction (SPME) and TFME, including one-step solvent-free extraction and preconcentration, direct thermal desorption, and enhanced sensitivity without sacrificing analysis time due to thin film geometry. The analytical performance of these new devices was demonstrated using water samples spiked with N-nitrosamines (NAs) as model compounds. Over an order of magnitude enhancement of extraction efficiencies was obtained for the model compounds compared with the SPME fibers of similar coatings and PDMS thin film membrane. The results of this study indicate that these novel thin film devices are promising for rapid and efficient microextraction of polar analytes in water.