Menu

UCL Department of Geography

Home

Description Photo Here

Personal tools
Log in
This is SunRain Plone Theme
UCL Home  /  Geography  /  Resources  /  Laboratory  /  Laboratory Methods  /  Lake Sediment Analysis  /  Cation Analysis

Cation Analysis

The following method has not yet been fully developed. It is recommended that several reference samples are analysed at the same time. Also include "reagent blanks" (adding no sample to the beakers but all the reagents).

Equipment

  • PTFE beakers
  • Hot Plate
  • 50ml Volumetric Flasks

Reagents

  • Hydrofluoric Acid
  • Nitric Acid
  • Hydrochloric Acid
  • 5M Hydrochloric Acid
  • De-ionised Water

Procedure

All beakers and flasks should be acid washed prior to use.

  1. Accurately weigh approximately 50mg of sample into the PTFE beaker.
  2. Add 2mls of Nitric acid and 8ml of hydrofluoric acid to each beaker.
  3. Place on the hotplate at 60°C for one hour.
  4. Increase the heat and evaporate to dryness.
  5. Allow to cool slightly and add 5ml of HCl to each beaker.
  6. Gradually increase the heat and evaporate to dryness.
  7. Add 10mls of 5M HCl and warm gently to dissolve. Cool.
  8. Make up to 50mls with de-ionised water in a volumetric flask.
  9. Decant into suitable containers and store in a fridge until analysed.

These samples are now ready for analysis using either ICP or AAS.