Legos Clean Lab

by Webmaster Legos last modified Jan 27, 2015 10:38 AM

Toulouse Marine Isotopy Clean Lab


  • To provide the necessary infrastructure for the chemical preparation of marine samples in view of the analyses of trace elements and isotopes.


Scientific Rationale

Trace elements and isotopes play important roles in the ocean as nutrients, as tracers of processes now and in the past, and as contaminants. Their biogeochemical cycling has direct implications for research in such diverse areas as the carbon cycle, climate change, ocean ecosystems, and environmental contamination.

Some of these trace elements and isotopes require clean sampling and chemical processing techniques. Clean labs provide clean workspaces necessary to prevent sample contamination during sample processing. The clean lab of the Toulouse Marine Isotopy Group is used to process seawater samples for the analyses of i) Nd isotopes and REE concentrations and ii) Fe isotopes and concentrations.

Nd isotopes and REE concentrations are used as tracers of i) large scale circulation, ii) land to ocean matter fluxes and iii) dissolved/particles interactions. Nd isotopes, robustly recorded in various sedimentary archives are also very useful in paleoceanography (although paleo work in not carried out in our group).

Fe isotopes provide a new tool for studying the Fe biogeochemical cycle and more widely, as iron in involved in the cycle of many other elements, oceanic biogeochemical cycles. First results suggest that this new tracer provide new and unique information about i) matter, and notably Fe, sources to the ocean, ii) dissolved/particles interactions, notably about Fe.


Schematic of the Toulouse Marine Geochemistry Group clean lab

Description of the facility

The Toulouse Marine Isotopy clean lab is composed of three main rooms, which air purity is classified ISO-7 or better (class 10 000 or better), totalizing ~43m2. In addition, 2 ISO-8 rooms are dedicated to weighing and mechanical instruments (oven, centrifuge…). The lab is equipped with particle free (ISO-1) evaporation spaces and laminar flow hoods. Pressure, temperature and humidity are permanently controlled and monitored.

Achievements over the period 2009-2014

Major modifications have been carried out during the past 5 years.

  •  Previous benches had metallic parts that corroded very quickly. There are now all plastic (PPH, 30k€ 2008).
  • Sealing of all rooms have been remade in order to prevent air leakage (7k€ 2009)
  • A new deionized water system has been acquired replacing our 14 years old one. The lab is now equipped with Q-Pod element milli-Q water (the purest water available at the time of purchase, 2011, 24k€).
  • The entire air treatment system has been rethought (2011, 120k€):

   - Terminal filtration is now at the ceiling (it was further away before) providing cleaner air and less noise.

   - Electrical heaters now allow

 - maintaining a decent temperature in winter (complementing the OMP provided hot water heater)

 - decreasing humidity in summer (before 100% humidity caused condensation at the ceiling)

  - All parameters are monitored and reported on a computer (see image below)

  - In case of a problem, alarms are sent by email and/or phone.


Electronic control of the clean lab air treatment system. The software displays all measurements (temperature, humidity, pressure, together with the status of the hardware), sends alarms when necessary and allows to set the targeted values (e.g. temperature etc.).


A huge effort has been made which resulted in very significant improvements during the last 5 years. No other modification is planned in the 5 years to come.

Participants: C. Pradoux, F. Lacan, M. Souhaut


LEGOS : Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (Toulouse); OMP.

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