| Summary: | 碩士 === 國立中正大學 === 化學研究所 === 89 === Abstract
A simple procedure was used to synthesize Poly(sodium N-undecylenic sulfate)(Poly-SUS) polymeric micells, which was applied to micellar electrokinetic capillary chromatography(MEKC) separation. anabolic steroids.
In the first part of this research, parameters that effect on the separation of four steroids were studied. These parameters include the concentration of buffer, the concentration of Poly-SUS, and the concentration of organic modifier, etc. From these parameters, the optimized separation conditions are 0.5%(w/v)Poly-SUS, 12.5mM sodium phosphate(pH=8), and 35%(V/V)acetonitrile. Such condition offers base-line separation of four anabolic steroids in five minutes. Also, Poly-SUS was examine for the feasibility of MEKC-MS.
In the second part of this research, on-line concentration of anabolic steroids by MEKC with Poly-SUS at high and low pH were studied. Low concentration phosphate buffer solution with Poly-SUS was used as separation buffer and high concentration of phosphate solution was used as sample matrix. This leads to the conductivity difference between the sample zone and the separation zone. Therefore, the mobility of the micelles at the two zones are difference. Hence the stacking process of neutral analyte on the micell boundary between sample zone and buffer zone was increase.
The experiment investigated the important parameters that were
effect on the stacking and seaparations of anabolic steroids.These parameters include the concentration of buffer, the concentration of Poly-SUS, the concentration of organic modifier and the concentration of samples matrix. At high pH value, the optimized conditions are 0.3%(w/v) Poly-SUS, 18mM sodium phosphate (pH=8), 30%(V/V) acetonitrile. The efficiency of stacking can improve the detection limits more than 200 folds. At low pH value, the optimized conditions are 0.5 % (w/v) Poly-SUS, 36mM sodium phosphate (pH=1.9), 30%(V/V)acetonitrile. The efficiency of stacking can improve the detection limits more than 300 folds.
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