【摘 要】
：
Micellar electrokinetic chromatography (MEKC) with diode array detector (DAD) was used to separate two dioxin-related compounds viz.2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodi
【机 构】
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Separation Science Research Group (SSRG), Department of Chemistry, Faculty of Science, Universiti Te
【出 处】
：
DaLian Internationall Symposia and Exhibition on Chromatogra
论文部分内容阅读
Micellar electrokinetic chromatography (MEKC) with diode array detector (DAD) was used to separate two dioxin-related compounds viz.2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 2,3,7,8-tetrachlorodibenzo-pfuran (TCDF).The optimum separation of these two compounds was achieved using 20 mM sodium cholate, 20 mM sodium tetraborate-decahydrate with acetonitrile:methanol (3∶1 , 5 % v/v) at a final buffer pH of 9.2.Separation wavelength was set at 225 nm using a diode array detector.Three online pre-concentration techniques viz.normal stacking mode MEKC (NSM-MEKC), reverse electrode polarity stacking mode MEKC (REPSM-MEKC) and high conductivity salt stacking mode MEKC (HCSSM-MEKC) were evaluated to compare the limit of detection, LOD obtainable for these two dioxin-related compounds.The LOD (S/N=3) obtainable with NSM, REPSM and HCCSM respectively were 0.34 ppm (TCDF) and 0.05 ppm (TCDD), 130 ppb (TCDF) and 3 ppb (TCDD), and 48.5 ppb (TCDF) and 18.5 ppb (TCDD).A 263-338-fold gain and 454-924 fold gain in detection sensitivity was obtained for these two compounds using REPSM-MEKC and HCSSM-MEKC and respectively.Combination of HCSSM-MEKC with off-line solid phase disk extraction (SPDE) reduces the LOD further to 48.5 ppt and 18.5 ppt for TCDF and TCDD respectively.
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