| Solid Phase Micro Extraction (SPME) has become an easy to automate technology for sample preparation in different application areas. However, for complex samples containing e.g. sugars or proteins, SPME was not ideal when using highly retentive adsorbent (particle) fibers for low LODs, because these matrix components adsorb strongly onto the adsorbent and are decomposed in the GC injector leading to fiber fouling and contamination of the GC injector port. A new line of SPME fibers with an overcoating layer of PDMS over the usual adsorbent fiber coating has been developed. With PDMS overcoating, large matrix components are repelled or can easily be washed off, while the smaller analytes of interest can pass through the outer PDMS layer and will be retained/extracted by the adsorbent. This presentation will compare the lifetime of overcoated to conventional adsorbent fiber coatings for complex matrices such as spaghetti sauce and show further application examples. |
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