The determination of Co in plant materials by radiochemical neutron activation analysis

The influence of irradiation conditions on the results of Co determination in plant samples by radiochemical neutron activation analysis (RNAA), after the conventional and microwave assisted wet digestion, has been investigat ed. Nine CRMs of botanical origin were examined. The study has demonstrated that the effectiveness of mineralization depended significantly on the kin d of sample and the irradiation conditions. When analyzed CRMs were subject ed to long-term irradiation in a high neutron flux, the mineralization usin g the microwave technique was necessary to obtain the correct results of Co determination in some of the plant samples. It has been proved that microw ave digestion in a mixture of HNO3+H2O2+ HF should be a standard method of wet ashing, independent on matrix and irradiation conditions.