Clean Room

House B B, B 206-211

Laboratory supervisors: Dr. Elis Hoffmann

CTA: Monika Feth

Purpose of the cleanroom laboratory in AB Geochemistry is the low-contaminated sample preparation and element separation for the isotope frequency and concentration determination of different elements in rock and mineral samples. For this purpose, the originally high number of particles in the outside air is considerably reduced by various pre-filters and HEPA filtration (H13) and blown into the clean room with a slight overpressure. The Cleanlab (a total of about 105 square meters) contain, beside a air lock, balance room and cleaning laboratory, a large and a small work area with workstations (laminar flow). Element separation and digestion takes place in 6 laminar flow cabinets (self-constructed with H13 filters), or in workstations (with H13-H14 filters).

Water must also be largely deionised before use (dilution of acids, cleaning). This is done by means of a two-stage procedure with firstly deionized water with ion exchangers and reverse osmosis, which is further deionized in a seralpur-unit to an extremely low conductivity (18.2 MW cm).

Acids must generally be distilled one or more times to obtain the low blank values required in some applications.

The spectrum of the elements that are currently separated in our clean room includes Rb-Sr, Sm-Nd and U-Pb for dating, Os and Ba for isotope frequency measurements as well as ultra trace elements such as the platinum group elements (PGE), Re and Au for concentration determinations.

Rock and mineral deposits are partly carried out in the clean room (acid digestion in a closed teflon beaker up to 180 ° C) or in the oven and digestion laboratory (B 233).

The most important separation methods include various methods of ion exchange chromatography and solvent extraction. 


for chemical seperation


Colums filled with anion exchange resin.


Cation exchange columns for separating the platinum group elements




Teflon-coated heating plate


Quartz glass distillates (for HCl and HNO3)


Teflon-distillates with heat lamps


Balance room


Ultra microbalance for weighing small quantities of samples



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