Apparatus to measure electrophoretic mobility of a flowing sample

An apparatus comprising:

• a fractionator configured to fractionate a sample solution comprising particles;
• a fluid inlet coupled to an outlet of the fractionator and coupled to a measurement chamber,
• wherein the fluid inlet is configured to introduce the sample solution into the measurement chamber;
• a measurement chamber coupled configured to allow the sample solution to flow in a direction essentially parallel to a path of a laser beam transmitted through the measurement chamber;
• a fluid outlet coupled to the measurement chamber,
• wherein the fluid outlet is configured to allow the sample solution to exit the measurement chamber;
• electrodes configured to generate an alternating electric field across the measurement chamber and essentially perpendicular to the direction;
• and
• a concentration detector coupled to the fractionator and coupled to the measurement chamber,
• wherein the concentration detector is configured to measure a concentration of each species in the sample solution, resulting in a measured concentration of the each species in the sample solution.