van Trigt R, Kerstel E R, Visser G H, Meijer H A
Centrum voor IsotopenOnderzoek, University of Groningen, The Netherlands.
Anal Chem. 2001 Jun 1;73(11):2445-52. doi: 10.1021/ac001428j.
We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta2H < or = 15,000/1,000, 18O < or = 1,200/1,000), as often used in the biomedical doubly labeled water (DLW) method to quantify energy metabolism. The method is an important extension of a recently developed infrared laser direct absorption spectrometer. The measurements on highly enriched, small-size (10 microL liquid water) samples show a clearly better accuracy for the 2H/1H ratio. In the case of 18O/16O, the same level of accuracy is obtained as with conventional isotope ratio mass spectrometer (IRMS) analysis. With LS, the precision is better for both 18O/ 16O and 2H/1H. New is the ability to measure 17O/16O with the same accuracy as 18O/16O. A major advantage of the present technique is the absence of chemical sample preparation. The method is proven to be reliable and accurate and is ready to be used in many biomedical applications.
我们证明了使用激光光谱法（LS）分析同位素高度富集水样（即δ²H ≤ 15,000/1,000，¹⁸O ≤ 1,200/1,000）的可行性，这种水样常用于生物医学双标记水（DLW）法中以量化能量代谢。该方法是最近开发的红外激光直接吸收光谱仪的一项重要扩展。对高度富集的小尺寸（10微升液态水）样品的测量显示，²H/¹H 比值的准确性明显更高。对于¹⁸O/¹⁶O，其准确性与传统同位素比率质谱仪（IRMS）分析相当。使用 LS 时，¹⁸O/¹⁶O 和 ²H/¹H 的精度都更高。新的进展是能够以与¹⁸O/¹⁶O 相同的精度测量¹⁷O/¹⁶O。本技术的一个主要优点是无需进行化学样品制备。该方法已被证明可靠且准确，可随时用于许多生物医学应用。
