Study on the Determination of Trace Ions in the Presence of High Concentration of Matrix by Simplified Column-Switching Ion Chromatography
简化柱切换技术在高浓度基体存在下测定痕量离子的研究

A simplified column-switching technique for the determination of trace ions in the presence of high concentration of matrix is established. A binary eluent mechanism is developed to study the effect of matrix on the shift of the analyte retention time. According to this mechanism, eluent of high concentration is preferred to suppress the peak shift of trace analyte caused by large amount of matrix. Since the peak shift has been effectively suppressed, the procedures for determining the column-switching time windows were greatly simplified. According to the different samples, different strategies should be employed in this technique. In this work, three typical samples were analyzed by this technique and the strategies for these three samples were studied to show the principles of choosing the proper separation conditions. Results showed that by this simplified technique analysis for trace analytes in the presence of complicated matrix was accurate and precise. The successful use of this method to the determination of trace bromate in drinking water, and nitrate, ammonium and iodide in sea water indicates that the application of this versatile technique to quantify analytes of low concentration in a wide range of sample matrices is promising.