Capillary electrophoresis CE is a powerful analytical technique used to separate and quantify different ionic species present in a sample based on their electrophoretic mobility. The following steps outline the process of determining the concentration of different ionic species using capillary electrophoresis:1. Sample preparation: Prepare the sample by dissolving it in an appropriate solvent, usually a buffer solution, to ensure that the ionic species are in their charged state. If necessary, perform sample cleanup or pre-concentration techniques to remove any interfering substances or improve the detection limit.2. Capillary selection: Choose a suitable capillary for the separation. The capillary is typically made of fused silica with an internal diameter of 25-100 m and a length of 30-100 cm. The capillary can be uncoated or coated with a specific material to modify the surface charge and improve separation efficiency.3. Buffer selection: Select an appropriate buffer solution to fill the capillary. The buffer should have a suitable pH and ionic strength to ensure the ionic species are charged and to control their electrophoretic mobility. Commonly used buffers include phosphate, borate, and acetate buffers.4. Instrument setup: Set up the capillary electrophoresis instrument by connecting the capillary to the high voltage power supply and the detector. The detector is usually a UV-Vis absorbance or fluorescence detector, but other detectors such as mass spectrometry can also be used.5. Sample injection: Inject the sample into the capillary using one of the injection methods, such as electrokinetic injection or pressure injection. The sample volume is typically in the nanoliter range.6. Separation: Apply a high voltage typically 10-30 kV across the capillary to create an electric field. The ionic species in the sample will migrate through the capillary according to their electrophoretic mobility, which is determined by their charge and size. The separation can be further optimized by adjusting the buffer composition, capillary temperature, and applied voltage.7. Detection and data analysis: As the ionic species pass through the detector, their presence is recorded as a function of time. The resulting electropherogram displays peaks corresponding to each ionic species, with the migration time and peak area proportional to their electrophoretic mobility and concentration, respectively. Identify the ionic species by comparing their migration times to those of known standards.8. Quantification: To determine the concentration of each ionic species, create a calibration curve by analyzing a series of standard solutions with known concentrations. Plot the peak area or peak height of each standard as a function of its concentration, and fit the data to a linear or nonlinear regression model. Use this calibration curve to calculate the concentration of each ionic species in the sample based on their peak area or height.By following these steps, you can successfully determine the concentration of different ionic species present in a sample using capillary electrophoresis.