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Use of an automated chromium reduction system for hydrogen isotope ratio analysis of physiological fluids applied to doubly labeled water analysis
Author(s) -
Schoeller Dale A.,
Colligan Amanda S.,
Shriver Timothy,
Avak Hairigh,
BartokOlson Cynthia
Publication year - 2000
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/1096-9888(200009)35:9<1128::aid-jms41>3.0.co;2-y
Subject(s) - chemistry , chromium , deuterium , urine , zinc , doubly labeled water , chromatography , isotope , analytical chemistry (journal) , radiochemistry , biochemistry , physics , organic chemistry , quantum mechanics , basal metabolic rate
Abstract The doubly labeled water method is commonly used to measure total energy expenditure in free‐living subjects. The method, however, requires accurate and precise deuterium abundance determinations, which can be laborious. The aim of this study was to evaluate a fully automated, high‐throughput, chromium reduction technique for the measurement of deuterium abundances in physiological fluids. The chromium technique was compared with an off‐line zinc bomb reduction technique and also subjected to test–retest analysis. Analysis of international water standards demonstrated that the chromium technique was accurate and had a within‐day precision of <1‰. Addition of organic matter to water samples demonstrated that the technique was sensitive to interference at levels between 2 and 5 g l −1 . Physiological samples could be analyzed without this interference, plasma by 10000 Da exclusion filtration, saliva by sedimentation and urine by decolorizing with carbon black.. Chromium reduction of urine specimens from doubly labeled water studies indicated no bias relative to zinc reduction with a mean difference in calculated energy expenditure of −0.2 ± 3.9%. Blinded reanalysis of urine specimens from a second doubly labeled water study demonstrated a test–retest coefficient of variation of 4%. The chromium reduction method was found to be a rapid, accurate and precise method for the analysis of urine specimens from doubly labeled water. Copyright © 2000 John Wiley & Sons, Ltd.