Evaluation of Neutral Loss, Precursor Ion Scan and Exact Mass Measurement for Identification and Characterization of GSH-trapped Reactive Metabolites

摘要

No current GSH method is truly universal: GSH adducts could be missed. The CNL and the PIS performed on a triple quadrupole are very well suited for automated screening. The first results of this comparison let appear that CNL of 129 in ESI~(+) suffers from a lack of sensitivity or specificity compared to the PIS of the 272 in ESI~(-). In both cases, and because of the triple quadrupole performance, a narrow mass range has to be selected to ensure a sufficient sensitivity. Consequently, the technique shows strong limitations with heterogeneous GSH conjugates charge species. Additionally, the low resolution power of the apparatus (especially in PIS mode) doesn't allow sometimes clear distinguishing between e.g. +305 and +307 or +321 and +323 GSH adducts and isotopic peaks (eg ~(35)Cl/~(37)Cl or ~(79)Br/~(81)Br) for chlorinated or bromined compounds.