Taiyo Nippon Sanso Corporation, 3-3 Mizuecho, Kawasaki-ku, Kawasaki, Kanagawa, Japan.
J Chromatogr A. 2010 Mar 12;1217(11):1838-44. doi: 10.1016/j.chroma.2010.01.039. Epub 2010 Jan 20.
Rapid analysis of trace permanent gas impurities in high purity ammonia gas for the microelectronics industry is described, using a gas chromatograph equipped with a phtoionization detector. Our system incorporates a reactive precolumn in combination with the analytical column to remove the ammonia matrix peak that otherwise would complicate the measurements due to baseline fluctuations and loss of analytes. The performance of 21 precolumn candidate materials was evaluated. Copper sulfate pentahydrate (CuSO(4).5H(2)O) was shown to selectively react with ammonia at room temperature and atmospheric column pressures, without affecting the hydrogen, oxygen, nitrogen, methane or carbon monoxide peak areas. To prevent loss of trace carbon dioxide, an additional boron trioxide reactant layer was inserted above the copper sulfate pentahydrate bed in the reactive precolumn. Using the combined materials, calibration curves for carbon dioxide proved to be equivalent in both ammonia and helium matrix gases. These curves were equivalent in both matrix gases. The quantitative performance of the system was also evaluated. Peak repeatabilities, based on eight injections, were in the range of 4.1-8.2% relative standard deviation; and detection limits were 6.9 ppb for H(2), 1.8 ppb for O(2), 1.6 ppb for N(2), 6.4 ppb for CH(4), 13 ppb for CO, and 5.4 ppb for CO(2).
描述了一种用于微电子行业高纯氨中痕量永久气体杂质的快速分析方法，使用配备光电离检测器的气相色谱仪。我们的系统结合使用了反应性前置柱和分析柱，以去除氨基体峰，否则基体峰的波动和分析物的损失会使测量变得复杂。评估了 21 种前置柱候选材料的性能。五水硫酸铜（CuSO(4).5H(2)O）被证明可以在室温下和大气柱压下与氨选择性反应，而不会影响氢、氧、氮、甲烷或一氧化碳的峰面积。为了防止痕量二氧化碳的损失，在反应性前置柱中的五水硫酸铜床层上方插入了另一个三氧化硼反应物层。使用组合材料，二氧化碳的校准曲线在氨和氦基体气体中均证明等效。这些曲线在两种基体气体中均等效。该系统的定量性能也进行了评估。基于 8 次进样的峰重复性在 4.1-8.2%相对标准偏差范围内；检测限为 H(2) 6.9 ppb、O(2) 1.8 ppb、N(2) 1.6 ppb、CH(4) 6.4 ppb、CO 13 ppb 和 CO(2) 5.4 ppb。
