The fragmentation of this ion (M[S.sup.2]) led to the formation of the m/z 175 (GlcA moiety) and m/z 243 fragment ions, the latter likely corresponding to hydroxylated BPA.
The M[S.sup.2] spectrum of this m/z 565 ion showed fragment ions due to the apparent loss of Glc (m/z 403) as well as a GlcA moiety (m/z 175).
In the same way observed for GlcA DH-BPA, the formation of the m/z 243 ion from the selected m/z 401 parent ion should correspond to the elimination of a neutral dehydrated glucuronide moiety.
Minor metabolites were also detected, and could correspond, on the basis of their [R.sub.t], to structures already identified from urine and digestive tracts extracts: GlcA-BPA-OH and GlcA-BPA-Glc, as well as H[O.sub.3]S-BPA (and/or HO-BPA), GlcA DH-BPA, and trace amounts of metabolites eluted with an [R.sub.t] of 22 min (only for liver extracts).
Further fragmentation of the m/z 385 ion was similar to that of GlcA DH-BPA.
Thus it was hypothesized that metabolite F was a GlcA conjugate of BPA, the GlcA itself being conjugated to N-acetyl-galactosamine (or N-acetyl glucosamine).
However, digestive tract extractions and subsequent radio-chromatographic analyses not only demonstrated the presence of BPA and GlcA-BPA, but also that of another major metabolite whose structure was that of a dehydrated glucuronide conjugate of BPA (GlcA DH-BPA).
The two major urinary metabolites detected by radio-HPLC were GlcA-BPA, as already evidenced in rat (3,34,35), and a newly identified GlcA conjugate of hydroxylated BPA, in which the hydroxylation takes place on one of the methyl groups of BPA (GlcA-BPA-OH).