Identification of xenobiotic metabolites from biological fluids using flow injection analysis high-resolution mass spectrometry and post-acquisition data filtering.
BACKGROUND
Concern for public health entails the need to evaluate the degree of exposure of population to toxicants. To do this, robust high-throughput approaches are required to be able to perform a large number of analyses in cohort studies. In this study, a data-filtering procedure was applied to mass spectral data acquired by direct analysis of biological fluids leading to rapid detection of metabolites in a model xenobiotic system.


METHODS
Flow injection analysis (FIA) coupled to negative electrospray ionization (ESI)-LTQ Orbitrap Fourier transform mass spectrometry was used to directly analyze urine of rats treated with vinclozolin. Tandem mass spectrometry (MS/MS) experiments were subsequently performed for confirmation of a new metabolite structure. The isotope filtering based on the difference between accurate masses of (35)Cl and (37)Cl was applied to the raw data for the specific detection of ions containing at least one chlorine atom.


RESULTS
Seven metabolites of vinclozolin were manually identified thanks to the characteristic isotope pattern of dichlorinated compounds. A new metabolite of vinclozolin was detected for the first time and identified as a sulfate conjugate. The application of an isotope-filtering procedure allowed the selective extraction of pertinent signals from the data. The processed mass spectrum was greatly simplified, significantly facilitating the detection of the seven metabolites previously identified.


CONCLUSIONS
The use of FIA-HRMS in combination with dedicated bio-informatics data processing is shown to be an efficient approach for the rapid detection of metabolites in biological fluids. This is a very promising high-throughput approach for rapid characterization of the exposure status to xenobiotics.
INRA, UMR1145 Ingénierie Procédés Aliments, F-75231, Paris, France; AgroParisTech, UMR1145 Ingénierie Procédés Aliments, F-75231, Paris, France; CNAM, UMR1145 Ingénierie Procédés Aliments, F-75231, Paris, France.
Estelle
E
Rathahao-Paris
Alain
A
Paris
Julian
J
Bursztyka
Jean-Philippe
JP
Jaeg
Jean-Pierre
JP
Cravedi
Laurent
L
Debrauwer
D000818:Animals; D017022:Flow Injection Analysis / Q000379:methods*; D008297:Male; D010080:Oxazoles / Q000378:metabolism / Q000652:urine; D051381:Rats; D017208:Rats, Wistar; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*; D015262:Xenobiotics / Q000378:metabolism* / Q000652:urine*
D010080:Oxazoles; D015262:Xenobiotics; C025643:vinclozolin