OR/14/067 Cerium phosphate precipitation

Lapworth, D J, Surridge, B, Williams, P J, Heaton, T H E, and Gooddy, D C. 2014. Method for analysing phosphate 18O/16O ratios for waters with high C:P ratios. British Geological Survey Internal Report, OR/14/067.

To each sample was added:

• 20 ml ultrapure water
• 4 ml 10% acetic acid
• 2 ml 1 M HNO₃
• 2 ml 0.5 M potassium acetate solution

The sample was then shaken, to fully dissolve the gel. The pH should be approximately 5.0 to 5.5 when fully dissolved, but KOH was added to adjust the pH if necessary.

• Add 800 mg cerium nitrate in 5 ml ultrapure water

The sample should go cloudy and must then be left at least overnight.