[en] Full text: An accurate determination of radioculides from various sources in the environmental samples is essential for assessment of the potential hazards and suitable countermeasures both in case of accidents, authorised release and routine surveillance. However, the concentrationof neptunium and plutonium is extremely low in environmental samples, and such samples have a complex matrix composition, which is to be taken into account for a proper analysis. Conventional radiochemical methods such as alpha spectrometry, neutron activation analysis, liquid, liquid scintillation system, fission track and gamma spectrometry for the quantitative determination of neptunium and plutonium often require complicated and time-consuming sample preparation and separation procedures. Due to the large amount of the complex and often unknown matrix, the analysis may also be covered by naturally occurring radionuclides. With the development of new analysis techniques, non-radioactive methods are increasingly used for the determination of trace or ultra-trace radionuclides in environmental samples. Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most suitable analysis techniques for the measurement of the long-lived radionuclides with its high sensitivity, low detection limits, short analysis time, less chemical interferences and multi-elemental capability. The throughput is therefore very high (approx.100 samples a day). The main objective of the present study was to set up of a simple, fast separation procedure to measure Np and Pu in the environmental samples ICP-MS. An unique extraction chromatographic column (TOA: tri-n-octylamine on Teflon powder) with a two-stage sample loading was prepared to separate Np and Pu from the environmental matrix. Np and Pu were efficiently retained in 4 M HNO₃ medium on the column and easiy eluted with 0.02 M oxalic acid 0.16 M HNO₃ at 95 C degree. The separated solutions were free from most of the matrix elements and were aspirated into the ICP-MS directly. The decontamination factor for ²³⁸U is more than 10⁴. The feasibility for the determination of both elements was proved by analysisng IAEA-135 reference samples, the measured values agreed with the recommended reference value. (author)