Supelco® Overcoated (OC) SPME Fibers
The over coating of fibers is a new technology in fiber coating to protect the SPME fiber from matrix components. This allows for immersion of the fiber directly into complex samples ensuring a more efficient extraction (e.g. of semivolatile compounds). Polydimethylsiloxane (PDMS) is used to overcoat a PDMS/divinylbenzene (DVB) fiber. The resulting fiber is more physically robust and resistant to chemical fouling and allows f…
A new development in SPME fiber technology incorporates a protective overcoating on the fiber. This overcoating, which consists of polydimethylsiloxane (PDMS) serves as a barrier to protect the fiber from the matrix, which makes it more physically robust and less prone to chemical fouling. High background samples, such as many foods, pose a challenge to immersion SPME due to the presence of fats, sugars, pigments, and other macromolecules. These can stick to the SPME fiber and reduce its usable life and/or be transferred to the GC, where they may interfere with chromatographic analysis. Overcoating the fiber with PDMS reduces these problems.