中国科学院大连化学物理研究所机构知识库
Advanced  
DICP OpenIR  > 中国科学院大连化学物理研究所  > 会议论文
学科主题: 分析化学
题名: Investigation on hollow fiber based liquid-liquid-liquid micro-extraction with different driving forces
作者: Wu Q(吴倩) ;  Wu DP(吴大朋) ;  Shen Z(沈铮) ;  Guan YF(关亚风)
会议文集: Investigation on hollow fiber based liquid-liquid-liquid micro-extraction with different driving forces
会议名称: 37th International symposium on High-Performance Liquid Phase Separations and Related Techniques
会议日期: 2011-10-8
出版日期: 2011
会议地点: 大连
通讯作者: 关亚风
出版者: 待补充
出版地: 待补充
合作性质: 分会特邀报告
部门归属: 105
主办者: 中国化学会色谱专业委员会和大连化学物理研究所
摘要: In recent years, hollow fiber based liquid-liquid-liquid micro-extraction (HF-LLLME) [1] has been widely studied due to its higher enrichment factor, excellent ability of clean-up, and lower consumption of organic solvent. In HF-LLLME, the driving force for analytes transferring from donor phase through organic phase into acceptor phase is the essential factor for HF-LLLME to obtain fast extraction with a high enrichment factor. By far, the driving force most widely used for HF-LLLME is pH gradient between donor phase and acceptor phase [2-4]. Donor phase is adjusted to favor the deionization of analytes and distributing into organic phase, while the acceptor phase is adjusted to favor the analytes ionization and dissolving in acceptor. Actually, the ion strength gradient is also used as an auxiliary driving force when pH gradient is used [3]. The composition of organic phase is another critical factor that influences the selectivity and clean-up ability of HF-LLLME. The long extraction time to reach equilibrium and the low extraction recovery are the major disadvantages of HF-LLLME [2]. Recently the electrical potential difference is explored as the major driving force for analytes mass transfer in HF-LLLME, and this method is commonly called as electro-membrane extraction (EME) [5]. In EME, pH of the donor phase is adjusted to favor the ionization of analytes, and the target ions transfer from donor to acceptor under the electric field. This method takes much shorter time and owns higher selectivity, but by far the composition of organic phase for various compounds with different polarity to get enough recovery is still limited, especially for acidic compounds. In our study, HF-LLLME with above mentioned different driving forces have been developed to analyze endogenous gibberellins from complex plant extracts and have been compared with each other. With the same organic phase (n-octanol), it was found that EME favors the extraction of gibberellins with low polarity, but HF-LLLME with pH gradient has no such selectivity. In HF-LLLME with pH gradient as the major driving force and ion strength gradient as the auxiliary driving force, an interesting phenomenon has been observed: the water osmosis has been found from the acceptor to donor, and this process has been demonstrated theoretically and experimentally that it is helpful to reduce extraction time to reach equilibrium and improve the extraction recovery. Series of weak anion-exchange extractants has been added into organic phase for EME to selectively extract more polar acidic compounds (logP<0.5). The relationship between the molecular structure of organic solvent and the system selectivity has been found. Finally, another new auxiliary driving force, the temperature gradient, has been proposed to get even higher extraction efficiency. REFERENCES [1] S. Pedersen-Bjergaard, et al., Anal. Chem. 71 (1999) 2650 [2] S. Pedersenbjergaard, et al., J Chromatogr A 1184 (2008) 132 [3] G. Shen, et al., Anal. Chem. 74 (2001) 648 [4] J. Wu, et al., J. Chromatogr A 1082 (2005) 121 [5] S. Pedersen-Bjergaard, et al., J Chromatogr A 1109 (2006) 183
英文摘要: In recent years, hollow fiber based liquid-liquid-liquid micro-extraction (HF-LLLME) [1] has been widely studied due to its higher enrichment factor, excellent ability of clean-up, and lower consumption of organic solvent. In HF-LLLME, the driving force for analytes transferring from donor phase through organic phase into acceptor phase is the essential factor for HF-LLLME to obtain fast extraction with a high enrichment factor. By far, the driving force most widely used for HF-LLLME is pH gradient between donor phase and acceptor phase [2-4]. Donor phase is adjusted to favor the deionization of analytes and distributing into organic phase, while the acceptor phase is adjusted to favor the analytes ionization and dissolving in acceptor. Actually, the ion strength gradient is also used as an auxiliary driving force when pH gradient is used [3]. The composition of organic phase is another critical factor that influences the selectivity and clean-up ability of HF-LLLME. The long extraction time to reach equilibrium and the low extraction recovery are the major disadvantages of HF-LLLME [2]. Recently the electrical potential difference is explored as the major driving force for analytes mass transfer in HF-LLLME, and this method is commonly called as electro-membrane extraction (EME) [5]. In EME, pH of the donor phase is adjusted to favor the ionization of analytes, and the target ions transfer from donor to acceptor under the electric field. This method takes much shorter time and owns higher selectivity, but by far the composition of organic phase for various compounds with different polarity to get enough recovery is still limited, especially for acidic compounds. In our study, HF-LLLME with above mentioned different driving forces have been developed to analyze endogenous gibberellins from complex plant extracts and have been compared with each other. With the same organic phase (n-octanol), it was found that EME favors the extraction of gibberellins with low polarity, but HF-LLLME with pH gradient has no such selectivity. In HF-LLLME with pH gradient as the major driving force and ion strength gradient as the auxiliary driving force, an interesting phenomenon has been observed: the water osmosis has been found from the acceptor to donor, and this process has been demonstrated theoretically and experimentally that it is helpful to reduce extraction time to reach equilibrium and improve the extraction recovery. Series of weak anion-exchange extractants has been added into organic phase for EME to selectively extract more polar acidic compounds (logP<0.5). The relationship between the molecular structure of organic solvent and the system selectivity has been found. Finally, another new auxiliary driving force, the temperature gradient, has been proposed to get even higher extraction efficiency. REFERENCES [1] S. Pedersen-Bjergaard, et al., Anal. Chem. 71 (1999) 2650 [2] S. Pedersenbjergaard, et al., J Chromatogr A 1184 (2008) 132 [3] G. Shen, et al., Anal. Chem. 74 (2001) 648 [4] J. Wu, et al., J. Chromatogr A 1082 (2005) 121 [5] S. Pedersen-Bjergaard, et al., J Chromatogr A 1109 (2006) 183
内容类型: 会议论文
URI标识: http://cas-ir.dicp.ac.cn/handle/321008/116114
Appears in Collections:中国科学院大连化学物理研究所_会议论文

Files in This Item:

There are no files associated with this item.


Recommended Citation:
Wu Q,Wu DP,Shen Z,et al. Investigation on hollow fiber based liquid-liquid-liquid micro-extraction with different driving forces[C]. 见:37th International symposium on High-Performance Liquid Phase Separations and Related Techniques. 大连. 2011-10-8.
Service
 Recommend this item
 Sava as my favorate item
 Show this item's statistics
 Export Endnote File
Google Scholar
 Similar articles in Google Scholar
 [吴倩]'s Articles
 [吴大朋]'s Articles
 [沈铮]'s Articles
CSDL cross search
 Similar articles in CSDL Cross Search
 [吴倩]‘s Articles
 [吴大朋]‘s Articles
 [沈铮]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
  Add to CiteULike  Add to Connotea  Add to Del.icio.us  Add to Digg  Add to Reddit 
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Powered by CSpace