Abstract
In order to reduce matrix effects that frequently occur in SPME analysis, the use of isotope-labeled compounds as an internal standard in conjunction with mass spectrometric detection is often indispensable. However, the commercially available number of such substances is small compared to the large number of analytically relevant compounds. In some cases, this gap can be reduced or even closed by in-housesynthesis of the required substances.
In the first part of this work, the substances 4-ethylphenol, 4-ethylguaiacol and 4-ethylcatechol required for the improvement of the SPME analysis of Brettanomyces off-flavor were prepared and purified in a partially deuterated form. The use of these compounds as internal standards in an SPME method developed by us resulted in good reproducibility, high sensitivity and no evidence of a significant matrix effect.