In my diploma thesis, I studied changes in the profiles of chromatographic peaks in ion chromatography, with an emphasis on retention time, asymmetry factor and tailing factor for peaks of sodium and potassium cations. The aim of the research was to determine how various factors, especially ion concentration, affect the shape of chromatographic peaks and the resolution between them.
The experimental work was based on the analysis of solutions of sodium and potassium ions using ion chromatography. Calibration and control solutions with different ion concentrations were prepared, and measurements were performed with an ion chromatograph. In the analysis, I monitored the repeatability of measurements and the influence of ion concentration on the shape of the peaks.
The results showed that fronting occurs with increasing concentration in sodium peaks, which indicates saturation of the stationary phase. I observed a more pronounced tailing phenomenon in potassium peaks, which decreased with increasing concentration. A key finding is that higher sodium concentration results in a shorter retention time for potassium, indicating competition between ions for binding sites in the chromatographic column. With increasing sodium concentration, the resolution between the sodium and potassium peaks decreased, which can pose a challenge in the simultaneous analysis of these ions.
The analysis revealed trends in chromatographic peak formation and highlighted the need to optimize analytical methods for efficient ion determination in complex samples. Although some trends were less reproducible, the findings contribute to a better understanding of the factors that affect chromatographic peak shape and analyte resolution.
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