| Summary: | 碩士 === 國立清華大學 === 生醫工程與環境科學系 === 96 === Determination of trace elements in high-salt content samples is always the most complicated and difficult to overcome analytical task, since it needs the robust instruments with high sensitivity and accuracy in the analytical system. Besides, there's lot of operation procedure to deal with saline sample prior to detection. Till now, various pretreatment methods, such as coprecipitation, solvent extraction, and ion exchange resin, were employed to separate analyte from matrix prior to the instrumental detection for the preconcentration of trace elements and matrix separation, however, the complicated operation procedure and the use of large volume of chemicals always lead to severe contamination and time-consuming. For purpose of simplifying the analytical procedure and minimizing the volume of chemicals, a non-functionalized PTFE tube as a solid phase extraction adsorbent was developed to couple with ICP-MS measurement.
In this study, we used PTFE tube as a SPE sorbent to determinate trace metal ions in dialysate of rat's brain and then introduced metal ions to ICP-MS. Compared to traditional SPE methods, the employment of complex/precipitation reagent and washing/conditioning of sorbent become ignored for in-tube SPE system. Thus, the contamination resulted from the reagents can be significantly minimized and higher analytical throughput can be achieved by online in-tube SPE method. To optimize the analytical performance, the effects of sample pH, sample flow rate, and acidity of eluent on the separation efficiency of in-tube SPE were investigated; in addition, the effect of salt matrix on the extraction efficiency was also studied. The detection limits of analyte ions were found in the range of sub ng/ml. The accuracy of the proposed method is confirmed by the analysis of certified reference materials of river and urine samples. Eventually, the on-line in-tube SPE-ICP-MS method was also applied to monitor in-vivo dynamic changes in the concentration of trace metal ions in the brain extracellular fluid; as long as, the concentration of analyte ions is higher than the detection limit, the variation of trace metal ions in brain can be observed.
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