The impact of temperature on the water isotope (²H/¹H, ¹⁷O/¹⁶O, ¹⁸O/¹⁶O) fractionation upon transport through a low-density polyethylene membrane

ABSTRACT

In the present study we investigated the isotope effects associated with water loss from closed low-density polyethylene (LDPE) bottles via diffusion at temperatures between 4 and 60 °C. While at low temperatures (4 and 10 °C) no substantial diffusional loss of water was observed within storage time, a pronounced loss was found for the experiments at room temperature and 60 °C. The latter was associated with a substantial increase in δ ¹⁸O, δ ¹⁷O, and δ ²Η values, and a decrease in the deuterium excess. The magnitude of the isotope effects essentially depended on the extent of water evaporation from the closed bottles through the LDPE membrane.

KEYWORDS:

• Deuterium excess
• diffusion
• hydrogen-2
• isotope fractionation
• LDPE
• oxygen-17
• oxygen-18
• polymer membrane bottle

Acknowledgements

The authors wish to thank L. Wassenaar for the provision of water samples from the WICO2011 proficiency test, and G. Wassmann for natural water samples. MEB wishes to further acknowledge G.H. Moh, for early inspiration on gas diffusion through polymer membranes, and acknowledges contributions from H.-J. H. Dohrenkamp, Y.N. Harari, C. Henn, and the blackbirds to the atmosphere during manuscript preparation. The publication is dedicated to Sir R. Starkey, on the occasion of his 80th birthday, and to the memory of A. Uderzo, both for their sense of humour, and A.U. for numerous big noses. The study was supported by the Leibniz Institute for Baltic Sea Research (IOW). We wish to thank A. Schimmelmann, an anonymous reviewer, and the handling editor G. Strauch for valuable comments that helped to improve the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.