Hu Zhaochu, Zhang Wen, Liu Yongsheng, Gao Shan, Li Ming, Zong Keqing, Chen Haihong, Hu Shenghong
State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences , Wuhan 430074, People's Republic of China.
Anal Chem. 2015 Jan 20;87(2):1152-7. doi: 10.1021/ac503749k. Epub 2014 Dec 29.
A novel "wave" signal-smoothing and mercury-removing device has been developed for laser ablation quadrupole and multiple collector ICPMS analysis. With the wave stabilizer that has been developed, the signal stability was improved by a factor of 6.6-10 and no oscillation of the signal intensity was observed at a repetition rate of 1 Hz. Another advantage of the wave stabilizer is that the signal decay time is similar to that without the signal-smoothing device (increased by only 1-2 s for a signal decay of approximately 4 orders of magnitude). Most of the normalized elemental signals (relative to those without the stabilizer) lie within the range of 0.95-1.0 with the wave stabilizer. Thus, the wave stabilizer device does not significantly affect the aerosol transport efficiency. These findings indicate that this device is well-suited for routine optimization of ICPMS, as well as low repetition rate laser ablation analysis, which provides smaller elemental fractionation and better spatial resolution. With the wave signal-smoothing and mercury-removing device, the mercury gas background is reduced by 1 order of magnitude. More importantly, the (202)Hg signal intensity produced in the sulfide standard MASS-1 by laser ablation is reduced from 256 to 0.7 mV by the use of the wave signal-smoothing and mercury-removing device. This result suggests that the mercury is almost completely removed from the sample aerosol particles produced by laser ablation with the operation of the wave mercury-removing device. The wave mercury-removing device that we have designed is very important for Pb isotope ratio and accessory mineral U-Pb dating analysis, where removal of the mercury from the background gas and sample aerosol particles is highly desired. The wave signal-smoothing and mercury-removing device was applied successfully to the determination of the (206)Pb/(204)Pb isotope ratio in samples with low Pb content and/or high Hg content.
一种新型的“波形”信号平滑和除汞装置已被开发用于激光烧蚀四极杆和多接收电感耦合等离子体质谱分析。使用已开发的波形稳定器，信号稳定性提高了6.6至10倍，并且在1 Hz的重复频率下未观察到信号强度的振荡。波形稳定器的另一个优点是信号衰减时间与没有信号平滑装置时相似（对于大约4个数量级的信号衰减仅增加1至2秒）。使用波形稳定器时，大多数归一化元素信号（相对于没有稳定器的信号）在0.95至1.0的范围内。因此，波形稳定器装置不会显著影响气溶胶传输效率。这些发现表明，该装置非常适合电感耦合等离子体质谱的常规优化以及低重复频率激光烧蚀分析，后者提供更小的元素分馏和更好的空间分辨率。使用波形信号平滑和除汞装置，汞气背景降低了1个数量级。更重要的是，通过使用波形信号平滑和除汞装置，硫化物标准物质MASS-1中激光烧蚀产生的(202)Hg信号强度从256 mV降低到0.7 mV。该结果表明，通过波形除汞装置的运行，汞几乎完全从激光烧蚀产生的样品气溶胶颗粒中去除。我们设计的波形除汞装置对于铅同位素比值和副矿物铀-铅年代测定分析非常重要，在这些分析中，非常需要从背景气体和样品气溶胶颗粒中去除汞。波形信号平滑和除汞装置已成功应用于低铅含量和/或高汞含量样品中(206)Pb/(204)Pb同位素比值的测定。
