Infrared Spectroscopy of Biological Fluids in Clinical and Diagnostic Analysis
Published Online: 15 DEC 2008
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Shaw, R. A. and Mantsch, H. H. 2008. Infrared Spectroscopy of Biological Fluids in Clinical and Diagnostic Analysis. Encyclopedia of Analytical Chemistry.
- Published Online: 15 DEC 2008
The infrared (IR) spectrum of a mixture serves as the basis to quantitate its constituents, and a number of common clinical chemistry tests have proven to be feasible using this approach. This article reviews the IR spectroscopy-based analytical methods that have been developed for consideration as clinical assays, including serum analysis, urine analysis, amniotic fluid assays for the estimation of fetal lung maturity, and others. Because of the widespread interest in the potential for in vivo measurement of blood glucose using near-IR spectroscopy, a separate section is devoted to the analysis of glucose in whole blood.
A related technique uses the IR spectrum of biomedical specimens directly as a diagnostic tool. For example, the spectra of serum and of synovial fluid have proven to be useful in the diagnosis of metabolic disorders and arthritis respectively, without explicitly recovering their chemical composition from the spectra. Rather, characteristic spectral features and patterns have been identified as the basis to distinguish spectra corresponding to healthy patients from those corresponding to diseased patients. These and other related applications to both human and veterinary health are reviewed here. Since diagnostic spectroscopy of cells and tissues are the subject of separate reviews within this volume, the scope of the present article is restricted to analytical and diagnostic spectroscopy of biological fluids.
Issues such as ease of use, speed, reliability, sample size, and calibration stability all play important roles in governing the practical acceptability of IR spectroscopy-based analytical methods. To provide a framework to illustrate these issues, descriptions are included for the various procedures that have been explored to successfully wed IR spectroscopy to clinical chemistry. Finally, a recent development promises to broaden the applicability of IR spectroscopy in both clinical analytical and diagnostic applications; the combination of microfluidics (laminar fluid diffusion interface) with spectroscopy of biofluids is outlined with examples illustrating the potential for this integrated technique.