Dear Chris,

Steven was ahead of me, but based on my experience DLW doses you mention indeed lead to much higher enrichments than the number Wolfram initially gave. Such doses are indeed not very custom for humans, but even higher ones are used for small animals (see for example our paper S. Guidotti, H. A. J. Meijer, and G. van Dijk, “Validity of the doubly labeled water method for estimating CO2 production in mice under different nutritional conditions,” AMERICAN JOURNAL OF PHYSIOLOGY-ENDOCRINOLOGY AND METABOLISM, vol. 305, no. 3, pp. E317–E324, 2013-05-28 2013.).

We have actually produced the new IAEA series of reference waters for DLW (V. Faghihi, B. M. A. A. Verstappen-Dumoulin, H. G. Jansen, G. van Dijk, A. T. Aerts-Bijma, E. R. T. Kerstel, M. Groening, and H. A. J. Meijer, “A new high-quality set of singly (2H) and doubly (2H and 18O) stable isotope labeled reference waters for biomedical and other isotope-labeled research,” Rapid Commun Mass Sp, vol. 29, no. 4, pp. 311–321, 2015.). While it is a lot of work to do the work accurately, making local ref waters for DLW is actually much simpler: by assuming the data by the manufacturer are right you can easily mix gravimetrically one or more reference waters in the desired range of  isotope values, that you subsequently calibrate using the IAEA waters. For calculation of isotope values: V. Faghihi, H. A. J. Meijer, and M. Groening, “A thoroughly validated spreadsheet for calculating isotopic abundances (2H, 17O, 18O) for mixtures of waters with different isotopic compositions,” Rapid Commun Mass Sp, vol. 29, no. 15, pp. 1351–1356, 2015.

This is quite a bit of self-advertising, I realise that, but I think these references are useful.

best regards,

Harro Meijer


Op 27 feb. 2017, om 11:25 heeft Wolfram Meier-Augenstein (pals) <[log in to unmask]> het volgende geschreven:

 
Hi Chris,
 
 
Steve’s e-mail made me realise I forgot to mention the delta values I quoted were based on studies using a dose of 0.03 g/kg body weight.  Sorry.
 
Speaking of which, as Steve has pointed out typical dosage used DLW studies in adults rarely exceeds 0.06 or 0.07 g/kg.  A higher dosage such as 0.1 g/kg may be used in studies involving children or infants however.
 
Best,
 
Wolfram
 
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Steve Brookes
Sent: 24 February 2017 10:21
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] DLW method
 

In our experience the post dose enrichment in DLW and TBW experiments leads to a deuterium delta value of ca. 800 permil. It is of course dependent on the dose given to the subject and their actual TBW. So you have to expect some to be quite a bit higher. In most cases researchers use 0.07 g/Kg of body weight for the dosing of the D2O. This means that for an 80 Kg adult they will get 5.6 g of D2O which will be then diluted in 40 Kg of water (assuming subjects are 50% water). The calculated delta value (assuming the natural body water is -50 permil) for such a dilution would be 758 permil.

So if you used a dose of 0.15 g D2O per Kg body weight (i.e. you give them 12 g of D2O) you would get a calculated (i.e. expected) delta value of 1681 permil for an 80 Kg subject.

We use our own prepared standards to cover the range (the upper standard having a calibrated deuterium value of 1701 permil).

Steve

Steven Brookes, PhD
Director
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Iso-Analytical Limited
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For up to date news visit our blog at:
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On 24/02/2017 06:01, Christian Dietz wrote:
dear all,
 
I would like to know with which levels of D and d18O I would have to count in urine after administrating up to to 0.28g/kg 18O and 0.15g/kg 2H.
 
Or less specifically, those found in experiments to determine Total Body Water and Total Energy Expenditure.
 
It's for achieving IAEA standards covering the range I may have to expect.
 
thx, as always
Chris
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