Improved Solvent Trapping of Volatiles in Supercritical Fluid Extraction by Pressurizing the Collection Vial
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- 作者：Mark A. Stone and Larry T. Taylor
- 刊名：Analytical Chemistry
- 出版年：2000
- 出版时间：March 15, 2000
- 年：2000
- 卷：72
- 期：6
- 页码：1268 - 1274
- 全文大小：100K
- 年卷期：v.72,no.6(March 15, 2000)
- ISSN：1520-6882
文摘
The high flow rates that result after decompression makethe trapping of analytes one of the more difficult aspectsof a supercritical extraction. By elevation of the pressureon the collection vial, the flow may be reduced andtrapping efficiency improved, considerably. The effects ofdifferent collection vial pressures were evaluated. The bestresults were obtained at 25 atm. With the collection vialat 25 atm, the trapping efficiencies of different solventswere then investigated. Also considered were the effectsof solvent volume, extraction flow rate, collection solventgeometry, and restrictor temperature. For a 30 minextraction-with the restrictor line at 200 
C-quantitativerecoveries were obtained with analytes as volatile aschlorobenzene (~90%) in 1 mL of solvent. Mild precoolingof the collection vessel allowed quantitative recoveries tobe obtained down to benzene (94.2%).
C-quantitativerecoveries were obtained with analytes as volatile aschlorobenzene (~90%) in 1 mL of solvent. Mild precoolingof the collection vessel allowed quantitative recoveries tobe obtained down to benzene (94.2%).