A Study on the Optimization Efficiency of Supercritical Fluid Extraction / Gas Chromatography of Polycyclic Aromatic Hydro- carbons

• Main Authors: Mei-Guei Chu, 朱玫瑰
• Other Authors: Da-Chang Lin
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/33464969769451827844

碩士 === 國立成功大學 === 環境工程研究所 === 82 === In general, high pressures, high temperatures, and long time enhance the solubility of PAHs and thus improve the of extraction. The results show that for low-molecular weight (2-ring naphthalene through 4-ring chrysene) pressure is the most dominant factor for extraction. For high-molecular weight PAHs, however, both pressure and temperature affect the recovery rate. The addition of a proper modifier helped the extraction. It was foumd that prior to the continuous pumping of modifier methylene chloride (CH2Cl2) into the extraction vessel during extraction, addition of 30 uL of CH2Cl2 to the XAD-2 resin improved the yield. The optimal extraction result was obtained when a 1-mL ertraction vessel was used, and the extraction was carried out at 380 atm 140C, with an addition of CH2Cl2 at 30 uL + 5.0 uL/min, 1 min. of static extraction, followed by 40 min. of dynamic extraction. these conditions, the recovery rate of all fourteen PAHs were above 96%. Compared to traditional Soxhlet extraction SFE/GC gave much recoveries of the fourteen PAHs. Also, while SFE yield 96% rate with only 40 minutes and 110 uL of methylene chloride, result from Soxhlet extraction required 33 hours and 800 mL of solvent, not to mention the problem of its subsequent waste disposal. In terms of both cleanness, time consumption, health and environmental impact, SFE is superior to traditional Soxhlet extraction. SFE will become a major useful and powerful tool in organic environmental chemical analyses. In the future, a simplified portable personal pump will be the hope to substitute the traditional PS-1 sampler for for shorter (1-2 hours) sampling periods, thus hourly variationtrations in the ambient air may be monitored. 3. concentrations in the ambient air may be monitored.