In vivo solid-phase microextraction swab-mass spectrometry for multidimensional analysis of human saliva.

Solid phase microextraction (SPME) is one of the most powerful sample preparation techniques for analyte extraction and enrichment from complex matrices. SPME fibers are commonly used to extract analytes from collected samples. Following our recent work on development of in vivo SPME swab that integrates an SPME fiber and a medical swab (Anal Chim Acta, 2020, 1124, 71-77), the multiple SPME fibers inserted into a medical swab (multiple-SPME swab) is further developed to couple with different mass spectrometry (MS) approaches for multidimensional analysis of human saliva in this work. The new features of cotton ball and SPME fiber of multiple-SPME swab are investigated. Biomarker discovery and disease diagnosis using multiple-SPME swab are also demonstrated. The present study shows that direct coupling multiple-SPME swab with different MS-based approaches could be simple and versatile in vivo method to expand the classes of analytes extracted simultaneously from human saliva.