Clay Mineralogy recipe data sheet


Cation saturation

 Reagent

 F.W.

g/mol

 Molarity of solution  g/liter H2O

 NaCl

 58.4

 1.0 M

 58.4

 KCl

 74.6

 1.0 M

 74.6

CaCl2

 111.1

 0.1 M

 11.1

 MgCl2

 95.2

 0.1 M

 9.5

 LiCl

 52.6

  1.0 M

 52.6

 RbCl

 158.5

  1.0 M

 158.5

 CsCl

 168.4

  1.0 M

 168.4

 SrCl2

 158.5

 0.1 M

 15.9

 BaCl2

 208.2

  0.1 M

 20.8

 NH4Cl

 53.4

  1.0 M

 53.4


Fe-hydroxide removal - Preparation of 0.3 M Na-citrate bicarbonate solution (buffered).

Sodium citrate dihydrate FW = 294.10 g.

1000 grams Na-citrate

952.9 grams NaHCO3

11.1 liters H2O

226 ml HCl (adjust to pH 7.6)

Approximate ratios of mixture to remove Fe-hydroxides.

0.5 grams sediment/soil/rock

1.2 grams sodium dithionite

50 ml citrate-bicarbonate


Carbonate removal - Preparation of buffered (pH 4) sodium acetate solution for dissolving carbonate.

Prepare 1 N solution of Na-Acetate ( CH3COONa FW = 82.03 g).

add 135 ml glacial aceatic acid per 500 ml of Na-Acetate solution. Adjust pH with additional glacial aceatic acid or NaOH until approximately

pH = 4.

50 ml citrate-bicarbonate


Organic removal - Add ~ 20 ml 30% H2O2 to ~ 2 grams of sample. 

Let stand overnight at room temperature.  Rinse with deionized water.

CAUTION! H2O2 is corrosive! and never completly seal the container!