| Autor: |
Luis Araguas-Araguas, Lorenzo Copia, Philipp Martin Klaus, Leonard I. Wassenaar, Darren J. Hillegonds, Stefan Terzer-Wassmuth |
| Rok vydání: |
2020 |
| Předmět: |
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| Zdroj: |
Rapid communications in mass spectrometry : RCMREFERENCES. 34(17) |
| ISSN: |
1097-0231 |
| Popis: |
Rationale Tritium (3H) is an important hydrological tracer that has been commonly used for over 60 years to evaluate water residence times and water dynamics in shallow/recent groundwaters, streams, lakes and the ocean. We tested the analytical performance of 78 international laboratories engaged in low‐level 3H assays for water age dating and monitoring of environmental waters. Methods Seven test waters were distributed by the IAEA to 78 international tritium laboratories. Set 1 included a tritium‐free groundwater plus three ultra‐low 3H samples (0.5–7 TU) for meeting groundwater dating specifications. Set 2 contained three higher 3H‐content samples (40–500 TU) suitable for testing of environmental monitoring laboratories. Results Seventy of the laboratories used liquid scintillation counting with or without electrolytic enrichment, seven utilized 3He accumulation and mass spectrometry, and one used gas‐proportional counting. Only ~50% of laboratories demonstrated the ability to generate accurate 3H data that was precise enough for water age dating purposes. Conclusions The proficiency test helped identify recurrent weaknesses and potential solutions. Strategies for performance improvements of 3H laboratories include: (a) improved quantification of 3H detection limits and analytical uncertainty, (b) stricter quality control practices in routine operations along with care and recalibration of 3H standards traceable to primary NIST standards, (c) annual assessment of tritium enrichment factors and instrumental performance, and (d) for water age dating purposes the use of electrolytic enrichment systems having the highest possible 3H enrichment factors (e.g. >50×). |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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