Erasmus Medical Center-Sophia Children's Hospital, Department of Paediatrics, Division of Neonatology, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
Rapid Commun Mass Spectrom. 2009 Nov;23(22):3549-54. doi: 10.1002/rcm.4279.
The doubly labelled water method is valuable for measuring energy expenditure in humans. It usually involves blood or urine sampling, which might be difficult in neonates and children with cerebral palsy or other disabilities. We therefore aimed to validate a method making use of saliva samples analyzed by automated thermal conversion elemental analyzer in combination with isotope ratio mass spectrometry (TC-EA/IRMS). The subjects received labelled water orally and urine and saliva samples were collected and analyzed. Deuterium as well as oxygen18 was measured in one single run using a peak jump method. Excellent linearity was found for measurement of enrichments of deuterium (R2 = 0.9999) and oxygen18 (R2 = 0.9999). The intra-assay precision and the inter-assay precision of the measurement of two standards were good for both deuterium and oxygen18. The variation between urine and saliva samples was small (4.83% for deuterium and 2.33% for oxygen18 n = 40). Saliva sampling is to be preferred, therefore, as it can be easily collected and is non-invasive. Moreover, its time of production is almost exactly known. The TC-EA/IRMS method is a good alternative to the more laborious off-line IRMS measurements.
双标记水法是测量人体能量消耗的一种很有价值的方法。它通常涉及血液或尿液采样，而在新生儿和脑瘫或其他残疾儿童中，这可能比较困难。因此，我们旨在验证一种利用唾液样本进行分析的方法，该方法采用自动热转化元素分析仪结合同位素比质谱仪（TC-EA/IRMS）进行分析。研究对象口服标记水后，采集和分析尿液和唾液样本。采用峰跃法在一次运行中同时测量氘和氧 18 的含量。结果表明，氘（R2=0.9999）和氧 18（R2=0.9999）的富集测量具有极好的线性。两种标准品的测量的批内精密度和批间精密度对氘和氧 18 均良好。尿液和唾液样本之间的差异较小（氘为 4.83%，氧 18 为 2.33%，n=40）。因此，首选唾液采样，因为它易于采集且是非侵入性的。此外，其产生时间几乎是确切可知的。TC-EA/IRMS 方法是一种比离线 IRMS 测量更繁琐的方法的良好替代品。
