Available online 8 October 2022

A Proof-of-concept study demonstrating solid phase microextraction (SPME) coupled to a Biocrates targeted metabolomics kit is presented for the first time.

SPME coupled to the Biocrates bioassay reveals drastic metabolome changes between intact and homogenized tissues.

SPME offers coverage of a great variety of analytes.

SPME is a desirable approach for delicate in vivo metabolomics studies.

Improved analytical methods for the metabolomic profiling of tissue samples are constantly needed. Currently, conventional sample preparation methods often involve tissue biopsy and/or homogenization, which disrupts the endogenous metabolome. In this study, solid-phase microextraction (SPME) fibers were used to monitor changes in endogenous compounds in homogenized and intact ovine lung tissue. Following SPME, a Biocrates AbsoluteIDQ assay was applied for downstream targeted metabolomics analysis and to confirm the advantages of in vivo SPME metabolomics. The AbsoluteIDQ kit enabled the targeted analysis of over 100 metabolites via solid–liquid extraction and SPME. Statistical analysis revealed significant differences between conventional liquid extractions from homogenized tissue and SPME results for both homogenized and intact tissue samples. In addition, principal component analysis revealed separated clustering among all three sample groups, indicating changes in the metabolome due to tissue homogenization and the chosen sample preparation method. Furthermore, clear differences in free metabolites were observed when extractions were performed on intact and homogenized tissue using identical SPME procedures. Specifically, a direct comparison showed that 47 statistically distinct metabolites were detected between the homogenized and intact lung tissue samples (p < 0.05) using mixed-mode SPME fibers. These changes were likely due to the disruptive homogenization of the tissue. This study’s findings highlight both the importance of sample preparation in tissue-based metabolomics studies and SPME’s unique ability to perform minimally invasive extractions without tissue biopsy or homogenization while providing broad metabolite coverage.

Solid-phase microextraction

solvent extraction

metabolomics

sample preparation

in vivo sampling

© 2022 The Author(s). Published by Elsevier B.V. on behalf of Xi’an Jiaotong University.