Profiling of sulfoconjugates in urine by using precursor ion and neutral loss scans in tandem mass spectrometry. Application to the investigation of heavy metal toxicity in rats.

This paper reports a liquid chromatographic/electrospray ionization mass spectrometric (LC/ESI-MS) method for profiling a wide range of structurally different sulfoconjugated compounds in urine and its application to the characterization of biomarkers for heavy metal toxicity in rat urine. Sulfoconjugates were first isolated by solid-phase extraction and the LC separation was performed on a reversed-phase column. Sulfoconjugates were detected in a triple-quadrupole mass spectrometer by simultaneously monitoring constant losses of 80 u (or 80 Th for doubly charged ions), precursors of m/z 80 (SO(3) (-*)) and precursors of m/z 97 (HSO4-).

Metabolite profiling in rat urine by liquid chromatography/electrospray ion trap mass spectrometry. Application to the study of heavy metal toxicity.

This work reports the use of reverse-phase liquid chromatography coupled to electrospray ion trap (QIT) mass spectrometry for the analysis of the metabolome in rat urine. An injection of 20 microL of urine into the chromatographic system is followed by a slow gradient elution and mass spectrometric detection in the scanning mode from m/z 100-1000 in both positive and negative modes. Over a time scale of 90 min, 30 and 20 resolved peaks were observed in the positive and the negative modes, respectively, corresponding to the presence of a few hundred m/z ratios.