Welcome to Stellenbosch University

BIOGRIP Node for Soil and Water Analysis Equipment Gallery

Metrohm IC 930 Ion chromatography system 

Instrument details (from left to right):

The Ion Chromatography instrument includes a Metrohm 858 Autosampler with 127 positions for sample introduction. It also offers options for inline autodilution and ultrafiltration of samples prior to analysis.

The anions are quantified using a Metrohm IC 930 compact IC Flex Oven/SeS/PP/Deg, which is equipped with a column oven, MSC and MSM module for sequential suppression, a peristaltic pump for suppressor regeneration and a built-in degasser. Detection and quantification of anions can be achieved using either a conductivity detector and/or an UV/VIS detector.

The cation are analysed using a Metrohm IC 930 compact IC Flex Oven/Deg equipped with a column oven and a built-in degasser.  The cations are quantified using a Conductivity detector. 


Typical applications include water chemistry analysis:

  1. Quantification of anions and cations to evaluate quality of drinking water​

GLA431-Triple liquid water isotope analyser from Los Gators Research (LGR)

Instrument Details

The Triple Liquid-Water Isotope Analyzer (T-LWIA) equipment uses High Resolution Laser Absorption Spectroscopy technique and simultaneously measures stable isotopes ratios, such as, Deuterium/Hydrogen (2H/H), 17Oxygen/16Oxygen (17O/16O) and 18Oxygen/16Oxygen (18O/16O) in liquid water samples with and electric conductivity of less than 25 000 (µS/cm) and a TDS 15 000 (mg/l).

It follows the Beer Lamberts' Law and computes isotopic ratios in terms of absorbance (LGR, 2009). The instrument is equipped with an auto sampler and vaporizer module to introduce the sample into the system.  This facilitates continuous stable isotope monitoring with minimal user involvement, thus, provides faster and timely generation of results compared to the conventional instrument. The instrument makes use of Off-Axis integrated cavity output spectroscopy to simultaneously measure δ17O, δ18O and δ2H in water samples. 

 Typical applications which are possible by measuring O/H stable isotopes

  • Tracking water through the water cycle, from rain to rivers to dams/lakes and groundwater.
  • Determining water provenance in products – e.g., where is the water in beverages derived from?
  • Ecosystem functions – e.g., which plants are dependent on rain and which on groundwater?
  • Domestic water supply – e.g., where does my tap water come from and how does it change?
  • Climate change studies – the rain in different climates has different isotopic signatures!

Lab Performance

Our lab's current QA/QC reports that precision and uncertainties are well below the acceptable ranges for hydrological studies which are:

  • δ18O – precision = <0.06 ‰ and uncertainty/repeats = <0.25 ‰
  • δ17O – precision = <0.04 ‰ and uncertainty/repeats = <0.1 ‰
  • δ2H – precision = <0.12 ‰ and uncertainty/repeats = <1.5 ‰