【摘要】 研究了感应耦合等离子体质谱(ICP MS)测定超痕量钚时的质谱干扰及干扰元素的去除;建立了环境水样中超痕量钚的测定方法。方法所用的解吸液适于ICP MS直接进样,并有效地消除铅等元素形成的多原子离子干扰。测量了溶液中的m/z238和2%HNO3空白液中的239Pu和242Pu计数率,对测量结果进行校正。方法的本底为20fg,方法对239Pu的检出限为43fg,测定限为88fg。所分析的水样中,井水中的239Pu含量低于检出限,地表水中239Pu的含量高于检出限,湖水和河水中的239Pu高于测定限,但属于全球沉降引起的本底,不会对公众造成辐射危害。更多还原

【Abstract】 The spectral interferences derived from metal U,Pb,Hg and Tl,may occur when ICP-MS is used to determine ultratrace plutonium,but, which could be eliminated by the separation procedure using anion exchange resin.The plutonium in water is isolated with Fe（OH）₃ （coprecipitation）,followed by purification using anion exchange resin with employing nitric acid and hydrochloric acid to rinse above mentioned ions. The eluate,0.01 mol/L HNO₃-0.01 mol/L HF,can be introduced directly to the sample injector,and is beneficial for the elimination of polyatomic PbCl⁺. The concentration of ²³⁹Pu in water is measured by isotope dilution using ²⁴²Pu as the spike after the reported （ratio,）²³⁹Pu/²⁴²Pu,has been calibrated with the intensity of m/z 238 in the sample and m/z 239, m/z 242 in the aqueous solution of 2% nitric acid. The minimum detection limit （MDL） is 43 fg, and the lower limit of determination （LLD） is 88 fg. Among the samples analyzed,the amount of ²³⁹Pu in the open area water is larger than the MDL,while it is lower than MDL in the deep well water,and the concentrations of （）²³⁹Pu are 1.1 fg/L and 0.68 fg/L in the regional lake and river,respectively.更多还原