Institute of Geological Sciences

Laboratories

Hydrochemistry Lab

The RWI Hydrochemistry Lab is devoted to the chemical analyses of groundwater and various extraction and experimental solutions. The quality of analyses is ensured by standard recovery and control tests during the analytical work and by regular participation in comparative tests with other laboratories. Detection limits for trace elements including redox-sensitive elements and oxy-anions are below the drinking water values recommended by Swiss and WHO regulations.

Specialities of the RWI Hydrochemistry Lab include:

Complete chemical analyses, including the stable isotopes of water, performed on very small volumes (1 mL) of porewater from various diffusion, extraction, squeezing and advective displacements experiments.
Analyses of metals dissolved in solution in the low ppb-range.
Analyses of redox-specific species in solution including oxy-anions in the low µg/L (or ppb)-range.
Analyses of solutions with complex matrices (e.g. CEC-solutions, waste seepage water) and of high ionic strength (>0.7 M, i.e. seawater).

Infrastructure and analytical techniques of the RWI Hydrochemistry Lab:

Field measurements:
measurement devices for pH, Eh, O2, EC, field-capable quick tests for various metallic compounds and alkalinity, and sample preservation tools for meta-stable redox-sensitive dissolved compounds for groundwater analyses.
Atomic adsorption spectrometry (HR-CS AAS) equipped with a graphite furnace and HydrEA technology:
routine single or multi-element trace element analyses and oxy-anions [Analytic Jena contrAA 700 BU].
Infrared spectrometry using a FR NDIR-detector:
analysis of total inorganic (TIC) and total organic carbon (TOC) in solution [Analytic Jena multi NC 2100S].
Ion-chromatography (IC):
routine major anions, cations and low molecular weight (LMW) organic compounds and specific trace and redox-sensitive elements [Metrohm ProfIC AnCat MCS and Metrohm IC Compact 861].
Inductively-coupled plasma – optical emission spectrometry (ICP-OES):
routine single or multi-element trace element analyses [Agilent Varian ICP-OES 700 ES].
Potentiometric techniques:
pH/Eh measurements for samples of very small volumes using microelectrodes [Thermo Scientific Orion Versastar system, Orion NWP microelectrode]
Spectrophotometry: specific redox-sensitive elements (e.g. Fe, Cr) and elements susceptible for colloid formation (e.g. Al, Si) [Varian and Merck Pharo 100].
Titration techniques:
alkalinity and selected ions using ion-selective electrodes [Metrohm Titrino DMP 785].