半导体制冷器件在国产电感耦合等离子体质谱仪上的应用

半导体制冷雾室是电感耦合等离子体质谱仪上广泛使用的器件,可以提高仪器的分析性能。将自研半导体制冷器件应用于电感耦合等离子体四极杆质谱仪,选取覆盖低、中、高质荷比的⁹Be、⁸⁹Y、¹¹⁵In、¹³⁸Ba、¹⁴⁰Ce和²⁰⁹Bi为研究对象,在雾室温度为0 ~ 20 ℃范围内考察了雾室温度对背景噪声、检出限、信号强度、氧化物产率、双电荷离子产率的影响。结果表明,半导体制冷雾室开启后,随着雾室温度的降低,⁹Be、¹¹⁵In和²⁰⁹Bi处的背景噪声分别下降51%、54%和29%;检出限随着雾室温度的降低呈现不同的趋势,⁹Be检出限随之降低,¹¹⁵In和²⁰⁹Bi检出限呈低水平波动趋势;载气流速偏低时,随着雾室温度降低信号强度呈下降趋势;载气流速偏高时,随着雾室温度降低信号强度随之下降的幅度减小,或者信号强度呈上升趋势;在开启制冷后,进入等离子体的水分减少,¹³⁸Ba和¹⁴⁰Ce的氧化物产率分别下降23%和31%;水分减少引起等离子体温度升高,双电荷离子产率分别上升16%和15%。

Application of Peltier-cooled device in domestic inductively coupled plasma mass spectrometer

The Peltier-cooled spray chamber is a widely used device in inductively coupled plasma mass spectrometer (ICP-MS), and it can improve the analytical performance of the instrument. The self-developed Peltier-cooled device was applied to the domestic inductively coupled plasma quadrupole rod mass spectrometer. ⁹Be, ⁸⁹Y, ¹¹⁵In, ¹³⁸Ba, ¹⁴⁰Ce, and ²⁰⁹Bi, which covered the low, moderate and high mass-to-charge ratio, were selected as the object of study. The effect of spray chamber temperature in range of 0-20 ℃ on the background noise, limit of detection, signal intensity, oxide yield, and yield of doubly-charged ions was investigated. The results showed that after using the Peltier-cooled device, as the spray chamber temperature decreased, the background noise at ⁹Be, ¹¹⁵In, and ²⁰⁹Bi decreased by 51%, 54%, and 29%, respectively. The limit of detection exhibited different trends with the decrease of spray chamber temperature: the limit of detection for ⁹Be decreased, while the limits of detection for ¹¹⁵In and ²⁰⁹Bi fluctuated at a low level. When the flow rate of carrier gas was low, the signal intensity decreased with the decrease of spray chamber temperature. When the flow rate of carrier gas was high, the reducing range of signal intensity decreased with the decrease of spray chamber temperature, or the signal intensity increased. After turning on the refrigeration, the water entering into the plasma decreased, and the oxide yields of ¹³⁸Ba and ¹⁴⁰Ce decreased by 23% and 31%, respectively. Less water led to the increase of plasma temperature, and the yields of double-charged ions increased by 16% and 15%, respectively.