The adsorption behavior of Barium and Radium on  Manganese 
Dioxide surface coated on   polyamide  was studied in order to 
use as a preconcentration  technique for Barium and Radium 
determinations. The Inductively Coupled Plasma – Atomic Emission 
Spectrophotometry (ICP – AES) technique was used to determine 
Barium concentration while the Liquid Scintillation Counter (LSC) 
technique was used to measure the Radium activity. Firstly Barium 
adsorption behavior was investigated in order to find out the 
optimum conditions for Barium adsorption on Manganese Dioxide 
surface.  The optimum conditions obtained were then used as the 
preconcentration technique for Radium. It was found that by using  
the corn - seed shape of polyamide as the supporting material for 
Manganese Dioxide, higher percentage of Barium adsorption 
(80 – 90%) can be observed as compared to the disc - flatted 
shape or other shapes.  Barium is adsorbed at pH 3 – 13, however 
the highest adsorption value was found for the solution of pH 5 – 7 
(89%). With a contacting time of 60 minutes, the adsorption of Barium  
on Manganese Dioxide was nearly saturated.  The amout of 
adsorbent used  depended on the surface area of Manganese 
Dioxide which was found to be approximately  0.45x10-6 mol /cm2 
of Manganese Dioxide surface.  Calcium was found to be the main 
interference that can reduce the adsorption of Barium on Manganese 
Dioxide surface.  Magnesium and Potassium also affected the 
Barium adsorption but Sodium showed no significant effect on Barium 
adsorption. 

The optimum conditions obtained from the previous studies were 
used for Radium determination in authentic water sample .  The 
percent recovery of Radium was found to be more than 80 %. 
However, by using this preconcentration technique for Radium 
determination in real water sample, a method for interference 
correction must be considered in order to reduce the error in the 
determination .