This report describes the environmental sample treatment techniques for14C measurement with liquid scintillation counter. The groundwater sample of about 80 liters was collected from well and inorganic
carbon was removed by acidification and recirculated gas stripping with the extraction efficiency of more than 98%. The biological
samples were freeze-dried and combusted to carbon dioxide in high pressure combustion unit with a combustion efficiency of
nearly 99%. The14CO2 in the stack effluents was collected by an air bubbler with a collection efficiency of more than 99% for a sampling time
of two weeks. Sampling of14C in reduced form also has been done by passing the gases through a tube furnace with Pt/Al and Pd/Al catalyst. Active and
passive sampling methods for atmospheric14C measurements were compared in detail, and it could be concluded that the uncertainty associated with passive sampling method
was quite acceptable for environmental monitoring. The CO2 trapped in NaOH was precipitated as BaCO3, and subsequently reconverted to CO2 for environmental samples and transferred to Carbo-Sorb ETM for liquid scintillation counting. In case higher precision is the deciding factor, benzene synthesis would be employed with
home-made benzene synthesizer.