ICP-MS测量超痕量钚时质谱干扰的消除及水中钚的测定  

Elimination of Spectral Interferences for ICP-MS and Determination of ^(239)Pu in Water

作　　者：金玉仁[1] 李梅[1] 李琳[1] 高晋峰[1] 倪惠云[1] 周国庆[1] 

机构地区：[1]西北核技术研究所,陕西西安710613

出　　处：《核化学与放射化学》2004年第1期6-10,共5页Journal of Nuclear and Radiochemistry

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。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 HNO_3-0.01 mol/L HF,can be introduced directly to the sample injector,and is beneficial for the elimination of polyatomic PbCl^+. The concentration of ^(239)Pu in water is measured by isotope dilution using ^(242)Pu as the spike after the reported (ratio,)^(239)Pu/^(242)Pu,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 ^(239)Pu 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 ()^(239)Pu are 1.1 fg/L and 0.68 fg/L in the regional lake and river,respectively.

关 键 词：钚 超痕量分析 质谱干扰 消除 环境水样 含量测定 ICP-MS 感应耦合等离子体质谱 放射性元素 环境监测 阴离子交换法 同位素稀释法 

分 类 号：X83[环境科学与工程—环境工程]