利用氣相層析質譜儀檢測空氣中二硫化碳之研究

Using Gas Chromatography /Mass Spectrometry to Detect Carbon Disulfide in Air

作業環境空氣中二硫化碳之採樣分析，通常使用活性碳管連接乾燥管採樣，再以甲苯脫附，使用氣相層析儀/火燄光度偵檢器（Gas Chromatography/Flame Photometric Detector, FPD）進行分析。FPD之感應並非線性關係，檢量線為曲線且線性範圍窄。於大量現場樣品分析時，常常需要稀釋樣品使落入檢量線範圍。本研究使用氣相層析質譜儀進行二硫化碳分析，有效延伸檢測範圍，由0.0013 mg/mL 至2.0 mg/mL，約1500 倍，解決原有FPD方法檢量線範圍窄的困擾，增進大量樣品分析便捷性。並於研究中發現二硫化碳以甲苯脫附之脫附效率，隨著濃度減少而降低。脫附效率由1.0 mg/樣品的95%降至0.10 mg/樣品的58%。本研究同時嘗試以Spherocarb 採樣管測試熱脫附方法，然因樣品分析變異過大，儀器分析條件仍待改進。

Air sampling and analysis method for carbon disulfide usually uses charcoal tube connected with dryer tube, desorbed by toluene and detected by Gas Chromatography/Flame Photometric Detector (FPD). However the response of FPD for sulfur is not linear and calibration range is narrow (only 10 times). For field sample analysis, samples should be diluted to fit the calibration range. In this study Gas Chromatography /Mass Spectrometry is utilized to detect carbon disulfide and its calibration range could be extended from 0.0013 mg/mL to 2.0 mg/mL (about 1500 times). Results indicated that the desorption efficiency for carbon disulfide extracted by toluene decreases as concentration decreases. The desorption efficiency for 1.0 mg/sample is 95%, however its only 58% for 0.10 mg/sample. Spherocarb tube for carbon disulfide thermal desorption is also investigated. Unfortunately the analytical coefficient of variation is unacceptable (about 15%). The thermal desorption analysis condition still need improvement.