Determination of p-tert-Octylphenol in Blood and Tissues by Gas Chromatography Coupled with Mass Spectrometry

Abstract

IA sensitive and reproducible procedure using gas chromatography coupled with mass spectrometry is described for the determination of p-tert-octylphenol (OP), a persistent degradation product of alkylphenol ethoxylates that binds to the estrogen receptor in blood and tissues. The first step involved the extraction of blood (200 pL) or tissue homogenate (400 pt) with methyl tert-butyl ether, including p-tert-butylphenol (BP) as internal standard. After extraction, the sample was evaporated to dryness with a gentle stream of nitrogen at 45~ and OP and BP were derivatized with an acetylation reaction involving acetic anhydride and catalyzed by pyridine. Samples were then analyzed by a gas chromatograph equipped with a mass spectrometer (single ion monitoring) with a Varian VF-5ms capillary column. The limit of detection and the limit of quantification of the method in blood were 4.6 and 15.5 ng/mL, respectively. The linearity and reproducibility of the method were acceptable, with coefficients of variation of approximately 10% for blood and ranging between 9% and 27% for tissues. This method was applied to the determination of unchanged OP in blood and tissues obtained from Sprague-Dawley rats after oral and IV OP administration.

Physiologically based modeling of p‐tert‐octylphenol kinetics following intravenous, oral or subcutaneous exposure in male and female Sprague–Dawley rats

“…The information pertaining to animal treatment and methods has been reported in more detail in two previous papers (Hamelin et al, 2008(Hamelin et al, , 2009. Briefl y, groups of fi ve male and fi ve female Sprague-Dawley rats were given a single dose of OP by oral (50, 125 or 250 mg kg ) or s.c. (125 mg kg −1 ) routes.…”