Wong W W, Lee L S, Klein P D
Am J Clin Nutr. 1987 May;45(5):905-13. doi: 10.1093/ajcn/45.5.905.
Improved methods to measure 2H:1H and 18O:16O isotope ratios on microliter samples of biological fluids are described. Enriched levels of 2H (580%) and 18O (256%) in urine, plasma, saliva, and human milk can be measured with a precision of 3.2% (n = 200) and 0.97% (n = 200) and an accuracy of -4.6 +/- 4.4% (mean +/- SD, n = 200) and -0.32 +/- 0.87% (mean +/- SD, n = 200), respectively. Hydrogen gas samples are generated from 10 microL of undistilled fluid by zinc reduction in quartz reaction vessels. Water-CO2 equilibration of a 100-microL sample for 18O measurement is completed in 10 h using a modified commercial equilibration system. These methodological improvements facilitate and extend the use of 2H and 18O tracers in studies of body composition and energy expenditure.
本文描述了用于测量生物体液微升样本中2H:1H和18O:16O同位素比率的改进方法。尿液、血浆、唾液和人乳中2H（580%）和18O（256%）的富集水平可分别以3.2%（n = 200）和0.97%（n = 200）的精度以及-4.6 +/- 4.4%（平均值 +/- 标准差，n = 200）和-0.32 +/- 0.87%（平均值 +/- 标准差，n = 200）的准确度进行测量。氢气样本通过在石英反应容器中用锌还原10微升未蒸馏的液体来生成。使用改良的商业平衡系统，100微升样本用于18O测量的水 - CO2平衡在10小时内完成。这些方法学上的改进促进并扩展了2H和18O示踪剂在身体成分和能量消耗研究中的应用。
