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Publication Detail
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Methods and applications of HPLC-AMS
Publish date: 2000
Author: Bruce A. Buchholz, Stephen R. Dueker, Yumei Lin, Andrew J. Clifford, John S. Vogel
Source: Nuclear Instruments and Methods in Physics Research B 172 (2000) 910-914
Pharmacokinetics of physiologic doses of nutrients, pesticides, and herbicides can easily be traced in humans using a
14C-labeled compound. Basic kinetics can be monitored in blood or urine by measuring the elevation in the 14C content
above the control predose tissue and converting to equivalents of the parent compound. High performance liquid
chromatography (HPLC) is an excellent method for the chemical separation of complex mixtures whose profles afford
estimation of biochemical pathways of metabolism. Compounds elute from the HPLC systems with characteristic
retention times and can be collected in fractions that can then be graphitized for AMS measurement. Unknowns are
tentatively identifed by co-elution with known standards and chemical tests that reveal functional groupings. Metabolites
are quantifed with the 14C signal. Thoroughly accounting for the carbon inventory in the LC solvents, ionpairing
agents, samples, and carriers adds some complexity to the analysis. In most cases the total carbon inventory is
dominated by carrier. Baseline background and stability need to be carefully monitored. Limits of quantitation near
10 amol of 14C per HPLC fraction are typically achieved. Baselines are maintained by limiting injected 14C activity
<0.17 Bq (4.5 pCi) on the HPLC column.
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