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Di(2‐ethylhexyl) phthalate metabolites as markers for blood transfusion in doping control: Intra‐individual variability of urinary concentrations
Author(s) -
Solymos E.,
Guddat S.,
Geyer H.,
Thomas A.,
Thevis M.,
Schänzer W.
Publication year - 2011
Publication title -
drug testing and analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.065
H-Index - 54
eISSN - 1942-7611
pISSN - 1942-7603
DOI - 10.1002/dta.377
Subject(s) - phthalate , metabolite , urine , chemistry , urinary system , glucuronide , chromatography , endocrinology , medicine , biochemistry , organic chemistry
To indicate homologous or autologous blood transfusion in sports drug testing, quantification of increased urinary concentrations of di(2‐ethylhexyl) phthalate (DEHP) metabolites presents a promising approach; however, the possible intra‐individual variation of the metabolite concentrations over time has not been well characterized. The aim of this study was to explore the intra‐individual variability of urinary DEHP metabolites among seven volunteers without special occupational exposure to DEHP during one week (n = 253) in order to investigate the possibility of increased urinary concentrations of the metabolites caused by, for example, residential, dietary, or environmental exposure. Quantification of three DEHP metabolites – mono(2‐ethylhexyl) phthalate, mono(2‐ethyl‐5‐oxohexyl) phthalate, and mono(2‐ethyl‐5‐hydroxyhexyl) phthalate – was accomplished after enzymatic hydrolysis of urinary glucuronide conjugates and direct injection using isotope‐dilution liquid chromatography‐tandem mass spectrometry. Although urinary concentrations of DEHP metabolites showed considerable intra‐individual variation, no increased values were observed comparable to the concentrations measured in urine specimens collected after blood transfusion. Copyright © 2011 John Wiley & Sons, Ltd.