The liquid chromatography mass spectrometry approach to measure amino acid isotope ratios.
OBJECTIVE
Although the application of liquid chromatography mass spectrometry has seen a rapid development in the world of clinical science since the introduction of atmospheric pressure ionization, its potential is still hardly recognized in the field of stable isotope biomedical research, as indicated by the small number of publications on this topic. Nevertheless, considering the polar nature of many biological substrates of interest as well as the non-destructive nature of electrospray ionization, a liquid chromatography mass spectrometry approach simplifies mass spectrometric spectra, allows the application of multiple labelled tracers, and provides an easy on-line sample processing, thus minimizing labour while at the same time providing concentration data and good reproducibility in low quantities of sample.


RESULTS
These features make it an excellent tool to perform both clinical and animal experiments that usually generate large numbers of samples, which when processed through the classic approach employing gas chromatography combustion isotope ratio mass spectrometry systems would require much more work and time and thus analytical costs.


CONCLUSIONS
The present paper is intended to introduce the functionality, limitations and options of representatives from the present family of modern liquid chromatography mass spectrometry systems into the field of stable isotope biomedical research, with a focus on amino acid metabolism.
van Eijk
Hans M H
HM
Department of Surgery, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, 6200 MD Maastricht, the Netherlands.
Deutz
Nicolaas E P
NE
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013997:Time Factors
D000596:Amino Acids