Abstract. A simple, rapid, cost-efficient, and robust method for separation of 237Np with an extraction chromatographic column (TOA: tri-n-octylamine on Teflon powder) is outlined in detail and further improved for direct ICPMS analysis. The column efficiently retained 237Np in 2molL1 HNO3 medium and all of the 237Np was easily eluted with 0.02molL1 oxalic acid in 0.16molL1 HNO3 at 95C. The separated solutions were free from most matrix elements and were aspirated into the ICPMS directly. The decontamination factor for 238U is more than 104. The instrumental detection limit for 237Np was 0.46pgmL1, which corresponds to 1.2105BqmL1. The method is more rapid than traditional radiometric techniques. It is also considered to be more suitable for environmental monitoring than existing methods based on TOA.