On-line microdialysis coupled with liquid chromatography for biomedical analysis.

This work presents a review of the microdialysis (MD) sampling technique for on-line coupling with high-performance liquid chromatography (HPLC) for biomedical analysis. MD-HPLC was first used in the field of brain metabolism to study neurotransmission, and this remains its common application in the biomedical field. On-line MD-HPLC hyphenated methods provide advantages over those with off-line MD-based techniques, including simplified sample preparation, automated analyses, avoidance of contamination introduced during the analytical process, and in situ analysis of the extracellular fluid of living organisms. This review outlines the effectiveness of the continuous monitoring of unbound chemicals from tissues, organs, and body fluids by on-line MD-HPLC methods. In addition, a discussion is presented on the application of in vivo on-line MD-HPLC toward obtaining biochemical event information in the extracellular fluid of various tissues and in biological fluids for pharmacokinetic, pharmacodynamic, toxicological, and bioprocess monitoring.