【摘要】 基于理论分析和实验考察,研究了过渡金属元素Zn,Cd,Cu和Ni挥发性物种的性质和发生效率的影响因素。详细地考察了介质酸度、进样体积、反应液混合管长度、载气流量、气液分离器和传输管线长度对荧光强度的影响,结果表明,反应介质酸度是影响氢化物发生效率的主要因素;较大的进样体积和较长的反应液混合管长度均不利于挥发性物种的产生和逸出;挥发性物种从反应液中快速而有效的逸出是影响蒸汽发生效率的重要因素;挥发性氢化物在传输过程中的分解或沉积,严重影响Zn,Cd,Cu和Ni的信号强度。在最佳条件下,Zn,Cd,Cu和Ni的蒸汽发生效率分别为61%,46%,69%和73%。通过对挥发性产物的捕集实验证明,Cd的挥发性物种是不稳定的氢化物分子CdH2,而Zn,Cu和Ni的挥发性物种是以"气溶胶"形态存在的稳定氢化物。更多还原

【Abstract】 Based on theoretical analysis and laboratory study,the influencing factors for the properties and generation efficiency of volatile hydrides of transition metals including Zn,Cd,Cu and Ni were studied.The effects of medium acidity,sampling volume,mixed tube length of reaction liquid,flow rate of carrier gas,gas-liquid separator and length of transfer pipeline on fluorescence intensity were investigated.The results indicated that reaction medium acidity was the key factor to influence generation efficiency of hydrides.Greater sampling volume and lengther mixed tube of reaction liquid were both disadvantageous to the generation and escape of volatile species.Rapid and effective escape of volatile matters from reaction solution was the key factor to influence generation efficiency of vapor.The decomposition or deposition of volatile hydrides in transportation seriously influenced the signal intensity of Zn,Cd,Cu and Ni.Under optimal conditions,the generation efficiencies of vapor for Zn,Cd,Cu and Ni were 61 %,46 %,69 % and 73 %,respectively.The trapping test of volatile species proved that the volatile species of Cd was an unstable hydride,i.e.CdH2,while the volatile species of Zn,Cu and Ni were the stable hydrides in the form of gasoloid.更多还原