热脱附谱方法的脱附速率灵敏度与四极质谱仪参数关系的实验研究

摘要

为了获得热脱附谱(TDS)方法的脱附速率灵敏度与四极质谱仪(QMS)参数的关系,以优化TDS高灵敏度分析的条件和参数,采用一种特制的通导型校准漏孔,基于QMS对氢同位素释放速率的二次离子检测(SEM)模式,研究了QMS仪器参数对TDS氘气脱附速率灵敏度的影响规律.实验结果表明,QMS的参数对TDS的氘气脱附速率灵敏度具有明显的影响,获得了实现TDS高灵敏度分析的QMS参数范围:发射电流1 000～1 400 μA;离子能量(栅极电压)3～3.5 V;电子能量50～70 V;聚焦电压-100～-60 V;分辨率-5～+5.%In order to assess the relationship between desorption rate sensitivity of thermal desorption spectroscopy (TDS) and parameters of quadruple mass spectrometer (QMS), also determine the optimized characteristics of TDS analysis, a high-sensitivity analysis method using a special deuterium calibration leak on the basis of e second electron multiplier mode of QMS was developed. The effect of parameters of QMS on desorption rate sensitivity was investigated. The results show that operation parameters of QMS affected obviously desorption rate sensitivity of TDS, the ion energy (gate voltage), electron energy, focus voltage, and the range resolution of the QMS should be adjusted to 1000-1400 μA, 3-rn3. 5 V, 50-70 V, -100- - 60 V and -5-+5, respectively. So the operating parametersrnof QMS were also optimized for high-sensitivity analysis of TDS.