Determination of fetogram plutonium by extraction chromatography using isotope dilution inductively coupled plasma mass spectrometry

This work reports the determination of fetogram plutonium using isotope dilution ICP - MS. The interference of protonated uranium at m/z of 239, with a determined UH+/U+ ratio of 4.6 x 10(-5), was removed by using tri-n-octylamine extraction chromatography. The separation factor of 10(4) was achieved for uranium and the recovery of plutonium was greater than 75%. By applying isotope dilution, fetogram range of plutonium was measured using a high - resolution ICP - MS with a sample volume of less than 1mL. The limit of detection of Pu-239 is 4.5 x 10(-15) g/mL for standard solution, and 16.3 x 10(-15) g/mL for real sample with matrix. The concentration of Pu-239 in region atmosphere was determined at a level of (4.8 +/- 2.9) x 10(-17) g/m(3).