Size exclusion (radio) chromatography of aqueous humic acid solutions withcesium and strontium

The high-performance size-exclusion chromatography (HPSEC) and radiochromat ography (HPSERC) was used for the identification of radiocesium and radiost rontium interaction with humic acid. It was found that the behavior of humi c acid on size-exclusion chromatography is sensitive to the salt concentrat ion and pH of the mobile phase. At lower ionic strength and in acidic regio n of pH, the Aldrich humic acid exhibited three main fraction within the ra nges >760 kDa, 25-100 kDa and <5 kDa. Radiocesium was found in the low-mole cular fractions (<1 kDa) of humic acids but radiostrontium interacts prefer ably with the fractions of humic acid of molecular weight within the range 2-5 kDa.