کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1207860 965283 2007 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Comparison of micellar isotherms of benzene determined by headspace gas chromatography and micellar electrokinetic chromatography: Assessment on impact of buffer and solubilization-induced conductivity change
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Comparison of micellar isotherms of benzene determined by headspace gas chromatography and micellar electrokinetic chromatography: Assessment on impact of buffer and solubilization-induced conductivity change
چکیده انگلیسی

The possibility is discussed that micellar isotherms determined by vacancy-micellar electrokinetic chromatography (vacancy-MEKC) differ from isotherms in electrolyte-free surfactants due to thermodynamic effects of buffer. Also discussed is the possibility that they are biased at high solute concentrations by solubilization-induced changes of electrical conductivity. Such bias could invalidate a theory on peak asymmetry of neutral solutes in MEKC that is based on thermodynamic interpretation of the isotherms. To evaluate these possibilities, the nonlinear concave upward isotherm of benzene in a pH 7.0, 0.0060 M sodium phosphate buffer containing 50 mM sodium dodecyl sulfate (SDS) was measured by headspace gas chromatography. Of interest is the finding that benzene is more stable in the surfactant-free buffer than in water. The isotherm was compared to that previously measured by vacancy-MEKC in the same buffer and 10, 30, or 50 mM SDS. No difference was found between the isotherms. However, the isotherm indeed differed from that of benzene in buffer-free 50 mM SDS, which was also determined and agreed favorably with previous results. A partial explanation is given for the independence of the vacancy-MEKC isotherm of solubilization-induced conductivity changes.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Chromatography A - Volume 1147, Issue 1, 13 April 2007, Pages 111–119
نویسندگان
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