Ion chromatography (IC ) coupled with ICP-MS was used to to 238U, 238U1H+ , 241Am and 244Cm on the 238, 239, 241 and 244 Pu isotopes, hinder its isotopic composition determination separate Np, Pu and U, overcoming the isobaric interferences present when the isotopic composition has to be determined as well as the quantification of the total amount of Pu in the sample. Moreover, 237Np cannot be accurately determined in and avoiding the influence of the tail of the 238U peak on the 237Np and 239Pu peaks in samples with a high U content. The the presence of a high content of U. The tail of the 238U peak partially masks the peak of the monoisotopic Np. A method optimization of the parameters was carried out with a standard solution containing Np, U and Pu (ratio 15151) at for the determination of 237Np in solutions having a high U content has been reported.11 The method involved time-the 100 ng ml−1 concentration level. The precision and accuracy of the method were also evaluated using a sample consuming sample handling. Furthermore, during the instrumental analysis by ICP-MS an offset continuous tension was containing 1 ng ml−1 of Np and Pu and 100 ng ml−1 of U. A 200 ml aliquot of the sample (previously treated with silver applied on mass 237 to obtain a better resolution between 237Np and 238U with a resulting decrease in sensitivity. oxide in order to obtain the elements in a single oxidation state) was injected and, after passing through the separation Nowadays, the determination of trace levels of actinides is mandatory for the control of the environment in the vicinity column, the effluent was passed directly to the nebulizer. Different mobile phases and oxidizing/reducing agents were of nuclear plants,12 after a nuclear accident such as that at Chernobyl,13 as well as for the detection of non-declared tested. The use of a high-capacity cation-exchange column (CS10), silver oxide as oxidizing agent and 40 m nuclear activities.14 Consequently, a method for the accurate determination of the total concentration and isotopic composi-2,3-diaminopropionic acid monohydronitrate in 0.6 HNO 3 as eluent in isocratic mode provided good resolution and recovery tion of actinides has to be available. The coupling of an on-line chromatographic system with ICP-MS, employing the method of the elements studied (96-98%). The precision of the method is 2.7, 1.1 and 1.7% for Np5U, Np5Pu and U5Pu, of isotope dilution for the determination of the total concentration, is a good combination to obtain precise and accurate respectively, for a solution containing Np, Pu and U in a ratio of 15151. Isotope dilution analysis applying IC separation was results. In our laboratory, a quadrupole ICP-MS instrument has been operating coupled on-line with an ion chromatograph performed for the determination of Pu. The method of standard additions was used for the determination of Np. The for more than 4 years,15 and methods for the determination of fission products in nuclear fuels have previously been described agreement between the IC-ICP-MS ...
