Monosegmented micro-volume liquid-liquid flow-extraction system based on intermittent pumping and spectroscopic detection

被引:16
作者
Carlsson, K [1 ]
Karlberg, B [1 ]
机构
[1] Stockholm Univ, Dept Analyt Chem, SE-10691 Stockholm, Sweden
关键词
liquid-liquid extraction; capillary extraction; micro-volume system; caffeine analysis;
D O I
10.1016/S0003-2670(00)00851-5
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
A micro-volume liquid-liquid flow-extraction system with on-capillary spectroscopic detection has been developed, exploiting the surface-enhanced capacity of small plugs of organic solvent to extract analytes from aqueous samples in 250 mu m i.d, silica columns. The organic solvent plug is monitored directly, while in the capillary, and a ceramic piston pump is used, allowing exact volumes of the aqueous sample and the organic solvent to be pulsed into the capillary. This pulsed flow increases the extraction efficiency. Sample and organic solvent volumes used in the trials reported here were in the ranges 180 nl-5.6 mu l and 50 nl-3 mu l, respectively. The utility of the system was demonstrated by extracting pharmaceutical samples containing caffeine (2.65 mu l) with chloroform (254 nl). This system is suitable for analyses where only small amounts of sample are available, e.g. for drug screening. (C) 2000 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:1 / 7
页数:7
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