Kim Ki-Hyun, Choi Gyoo-Hoon, Choi Ye-Jin, Song Hee-Nam, Yang H-S, Oh J-M
Department of Earth and Environmental Sciences, Sejong University, Seoul, Republic of Korea.
Talanta. 2006 Feb 28;68(5):1713-9. doi: 10.1016/j.talanta.2005.08.037. Epub 2005 Sep 16.
In this study, the analytical bias in the measurements of reduced sulfur compounds (RSC) was investigated in terms of sorptive loss caused by the materials selected for the sample introduction. For the purpose of this study, three vacuum samplers made in the combination of different vacuuming efficiencies (e.g., rapid versus slow sampling) and different materials (i.e., Teflon versus stainless steel (SS)) were tested to evaluate the sampling recovery rate (RR) for five RSCs: H(2)S, CH(3)SH, DMS, CS(2) and DMDS. To make a parallel comparison of RR, the RSC standard samples contained in one bag were transferred to another bag using each sampling system. Their relative contents between, before, and after the transfer were then evaluated between different samplers to assess the sampling bias caused by the interaction between RSC and the sampling material. In the case of the most reactive compound, H(2)S, the sampling loss from the SS inlet line amounted to as high as 45%, while that for the Teflon counterpart was almost insignificant. When the sampling time was arbitrarily elongated (i.e., use of a slow sampler), the sampling loss rate of the SS inlet sampler became more significant with the RR values dropping down from 55 to 70%, across different RSCs. The overall results of our comparative study indicate that the sampling system for the reactive gaseous compounds should be checked for the material feasibility to guarantee sufficient analytical reliability.
在本研究中，针对因样品引入所选用材料导致的吸附损失，对还原态硫化合物（RSC）测量中的分析偏差进行了研究。为开展本研究，测试了三种由不同抽气效率（如快速采样与慢速采样）和不同材料（即聚四氟乙烯与不锈钢（SS））组合制成的真空采样器，以评估五种RSC（硫化氢、甲硫醇、二甲基硫醚、二硫化碳和二甲基二硫）的采样回收率（RR）。为了对RR进行平行比较，使用每个采样系统将一袋中的RSC标准样品转移至另一袋中。然后评估不同采样器之间转移前后的相对含量, 以评估RSC与采样材料之间相互作用所导致的采样偏差。对于反应性最强的化合物硫化氢而言，不锈钢进样管线的采样损失高达45%，而聚四氟乙烯进样管线的采样损失几乎可以忽略不计。当任意延长采样时间（即使用慢速采样器）时，不锈钢进样采样器的采样损失率变得更加显著，不同RSC的RR值从55%降至70%。我们比较研究的总体结果表明，对于反应性气态化合物的采样系统，应检查材料的可行性，以确保足够的分析可靠性。
