Journal of University of Chinese Academy of Sciences >
Membrane Extraction and Flow Injection for On-Line Sample Preparation
Received date: 2003-01-03
Online published: 2003-07-10
The objective of this dissertation is to develop on-line sample preparation procedures based on membrane extraction and flow injection (FI) techniques. A novel sample pretreatment technique, which we termed continuous flow liquid membrane extraction(CFLME), was developed for trace-enrichment of polar organic pollutants. The principle and parameters of CFLME were investigated by using sulfonylurea herbicides and bisphenol A as model compounds. At the optimum conditions and with an enrichment time of 120 min and 40 min, metsulfuron methyl and bisphenol A were enriched with an enrichment factor of 1000 and 200, respectively, and the enrichment efficiencies of bisphenol A and the five studied sulfonylurea herbicides were 3.5 ～ 200 fold of that of supported liquid membrane extraction (SLM). Then,an on-line coupled CFLME-HPLC system, with detection limits of 0.05 ～ 0.1 μg/L after 10min of enrichment, was developed for the determination of sulfonylurea herbicides. Futhermore, an on-line coupled CFLME-C18 precolumn-HPLC system was developed for the trace analysis of sulfonylurea herbicides in surface waters at ng/L level. The detection limit of this proposed CFLME-C18 precolumn-HPLC system is 200 fold lower than that of the original C18SPE preconcentration-HPLC detection method. Experiments show that the proposed CFLME technique has the advantages of high selectivity, high enrichment efficiency, low-cost, longterm stability and convenience for coupling on-line with other analytical instruments.On-line sample pretreatment procedures based on FI technique were also studied and approaches for the application of FI technique in routine analysis were proposed. A FI-micropore membrane liquid-liquid system was developed for the routine analysis of anionic surfactants in detergents, and a FI high temperature reaction system was developed for the determination of total inorganic phosphates in detergents and the total reducing sugars in tobacco. To simplify the manifold, aregent-injection-FI technique was proposed for the elimination of matrix background absorption in the determination of chloride in tobacco.
Key words： on-line sample preparation; membrane extraction; flow injection
Liu Jingfu , Jiang Guibin . Membrane Extraction and Flow Injection for On-Line Sample Preparation[J]. Journal of University of Chinese Academy of Sciences, 2003 , 20(4) : 504 -509 . DOI: 10.7523/j.issn.2095-6134.2003.4.018
［1］Liu Jing-Fu, Chao Jing-Bo, Jiang Gui-Bin. Continuous flow liquid membrane extraction: a novel automatic trace-enrichment technique based on continuous flow liquid-liquid extraction combined with supported liquid membrane. Anal Chim Acta, 2002, 455:93～101
［2］Liu Jing-Fu, Chao Jing-Bo, Wen Mei-Juan, Jiang Gui-Bin. Automatic trace-enrichment of bisphenol A by a novel continuous flow liquid membrane extraction technique. J Sep Sci, 2001, 24:874～878
［3］Chao Jing-Bo, Liu Jing-Fu, Wen Mei-Juan, Liu Jie-Min, Cai Ya-Qi, Jiang Gui-Bin. Determination of sulfonylurea herbicides by continuous flow liquid membrane extraction on-line coupled with high performance liquid chromatography. J Chromatogr A, 2002,955:183～189
［4］Liu Jing-Fu, Chao Jing-Bo, Jiang Gui-Bin, Cai Ya-Qi, Liu Jie-Min. Trace analysis of sulfonylurea herbicides in water by an on-line coupled continuous flow liquid membrane extraction-C18-precolumn-HPLC/UV system. J Chromatogr A, 2003, 995:21～28
［5］Liu Jing-Fu, Jiang Gui-Bin. Determination of anionic surfactants in detergents by microporous membrane liquid-liquid extraction and flow injection spectrophotometry. Microchem J, 2001, 68:29～33
［6］Liu Jing-Fu, Jiang Gui-Bin. Selective determination of orthophosphate and total inorganic phosphates in detergents by flow injection photometric method. Talanta, 2000, 52:211～216
［7］Liu Jing-Fu, Jiang Gui-Bin. Spectrophotometric flow injection determination of total reducing sugars in tobacco based on oxidation by ferricyanide and formation of Prussian blue. Anal Lett, 2001, 34:1923～1934
［8］Liu Jing-Fu, Jiang Gui-Bin. Evaluation of a reagent-injection flow injection technique for sample background absorption elimination:Determination of chloride in cigarettes. Talanta, 2001, 54:329～332
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