Determination of halophenolic wood preservant traces in milk using headspace solid-phase microextraction and gas chromatography-mass spectrometry.

Claudia Mardones, Dietrich von Baer, Jorge Silva, Maria José Retamal

Index: J. Chromatogr. A. 1215(1-2) , 1-7, (2008)

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Abstract

Extraction of 2,4,6-tribromophenol (TBP), pentachlorophenol (PCP) and pentachloroanisole (PCA) from whole fat cow milk using headspace solid-phase microextraction (HS-SPME) with polyacrylate (PA) and polydimethylsiloxane (PDMS) fibers was evaluated and compared. The PA was studied to extract PCA, TBP and PCP, while PDMS was used to extract PCA and acetyl derivatives of PCP and TBP. The parameters: fiber position, matrix effect, temperature and extraction time were studied. The analysis was made by gas chromatography coupled with mass spectrometry. The results show that the distance between fiber and milk had a significant effect on the extraction kinetics. Also, the fat content in milk was a critical parameter that clearly affected the extracted mass of each compound. By using a PA fiber, the sensitivity for PCA and TBP was higher than that obtained with PDMS fiber; however, PA fiber did not allow PCP determination. The recoveries from milk were 95+/-4%, 96+/-2% and 96+/-4% for PCP, TBP and PCA, respectively, with the PDMS fiber and 94+/-3% and 95+/-1% for TBP and PCA, respectively, with PA fiber. The method using PDMS fiber was applied to real whole milk samples.