Development of Online Microdialysis–Microfluidic-Based Photocatalyst-Assisted Vaporization Device–Inductively Coupled Plasma-Mass Spectrometry Hyphenated Analytical System for in vivo Quantification of the Transition of Brain Extracellular Mercury after Thimerosal Administration

Abstract In this study, an ultrasensitive and salt-tolerant online microdialysis–microfluidic-based photocatalyst-assisted vaporization device–inductively coupled plasma-mass spectrometry (MD/μFPCAVD/ICPMS) hyphenated analytical system was developed for the in vivo quantification of the transition of mercurial concentration level in the extracellular fluid (ECF) of rat brains after the administration of thimerosal (TMHg). Under optimal operation conditions, the limits of detection (based on 3σ) of the proposed analytical system for methylmercury (MMHg) and TMHg in the saline solution corresponded to 2.7 and 1.7 ng L−1, respectively. We demonstrated the applicability of our proposed analytical system for animal experiment via observations of the variation in ECF mercurial concentration level after the administration of MMHg and TMHg. The results suggested that TMHg can penetrate through the blood–brain barrier as MMHg via an unclear mechanism. Based on the obtained results, our proposed analytical system exhibits satisfactory reliability and validity to monitor the transition of the ECF mercurial concentration level after the TMHg is administered. Hence, our proposed analytical system can provide a potential alternative method for toxicological research of TMHg in the brains of living animals.