Development of rapid sample preparation method for environmental samples for gamma spectrometry

Rapid measurement of radionuclide (RN) concentration is an important requirement in emergency situations for making initial advisories and initiating appropriate countermeasures. Most of the RN encountered in emergency situation can be determined using γ ray spectrometry nondestructively without any chemical separation. Sample preparation for sample counting using gamma spectrometry involves homogenization and dry ashing to preconcentrate the radionuclide into a smaller volume and also to obtain a pre-determined geometry. By preconcentration the amount of RN of interest per unit mass of analyzing sample can be increased. Oven drying, evaporation, freeze drying and dry ashing are few absolute methods used. Dry ashing procedures using conventional muffle furnace often takes more than a day for completion and has little control over the heating temperatures. With the advent of microwave based units, ashing time can be reduced significantly. These ashed samples will be counted in low background graded shielded gamma spectrometer for activity determination