[HPLC-MSn analysis of trigonelline and its metabolites in rat urine].

Aim: To establish a rapid and sensitive LC-MSn method for the identification of trigonelline and its main metabolites in rat urine.

Methods: After optimizing the detection conditions of LC-MSn chromatography and mass spectrometry using trigonelline, its ionization and cleavage in ESI-MS and ESI-MSn modes were summarized, then serving as the basis for the metabolite analysis of trigonelline in rat urine. The 0-48 h urine samples of rats were collected after iv 8 mg x kg(-1) trigonelline, then, the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by LC-MSn.

Results: The structures of trigonelline metabolites were elucidated according to the changes of the molecular weights of the metabolites (deltaM) and their cleavage pattern in ESI-ITMSn. As a result, two phase I metabolites and the parent drug were identified existing in rat urine, and two phase II metabolites were identified.

Conclusion: The LC-MSn method is rapid and high sensitive and specific, it is suitable for the identification of trigonelline and its metabolites in rat urine.