Solid-phase microextraction of endogenous metabolites from intact tissue validated using a Biocrates standard reference method kit.

"Declaration of competing interest The authors declare that there are no conflicts of interest (including Biocrates Life Sciences)."

"The authors would like to thank Biocrates Life Sciences (Innsbruck, Austria) for providing the AbsoluteIDQ p180 kit as well as their technical support. This work was supported by the 10.13039/501100000038Natural Sciences and Engineering Research Council of Canada, NSERC (Grant No.: IRCPJ 184412-15). Runshan Will Jiang: Methodology, Validation, Formal analysis, Investigation, Data curation, Writing - Original draft preparation, Reviewing and Editing, Visualization; Karol Jaroch: Conceptualization, Methodology, Validation, Formal analysis, Investigation, Data curation, Writing - Reviewing and Editing, Visualization; Janusz Pawliszyn: Resources, Writing - Reviewing and Editing, Supervision, Funding acquisition."