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The boron content of uranium fuel samples with boron concentrations in the range of 0.05-10 μg/g was determined using inductively coupled plasma optical emission spectrometry (ICP-OES) after the uranium was separated by cation exchange.The samples were dissolved in 3 M HNO3on a hot plate at 150℃ and evaporated to near dryness. The residues were redissolved in 0.2 M HNO3and passed through a column loaded with Dowex 50WX8-400 resin. Uranium was adsorbed on the resin, while boron was easily eluted with 0.2 M HNO3. The boron content of the effluent was determined using ICP-OES. Several strategies were employed to improve the reliability of the experimentally determined boron content. The addition of mannitol and proper control of the evap-oration process were shown to be effective in preventing boron loss during sample dissolution and evaporation.The memory effect was eliminated by flushing the system with 1.5% ammonia for 30 s between successive sample runs, and the matrix match method was used to eliminate the matrix effect arising from mannitol during the ICP-OES analysis. The accuracy of the results of the analysis was determined by addition recovery tests and by comparison with the results of three Chinese certified reference mate-rials (GBW04242, GBW04243, and GBW04232). Using the method we developed,the limit of detection for boron was as low as 0.05 μg/g in uranium fuel samples,and the relative standard deviations for 0.1-0.5 g uranium samples with 0.05-2 μg/g of boron were within 9%.