Image Analysis of Separation Processes. I. Development of a Video Image Analyzing System and Its Fundamental Application to the Direct Observation of a Separation Process in a Column.

Real-Time Imaging through Optical Fiber Array-Assisted Laser-Induced Fluorescence of Capillary Electrophoretic Enantiomer Separations

“…In addition, investigation of the course of events during the separation is not possible. The recently introduced methodologies of real-time detection and monitoring, using Schlieren shadowgraph 2 and absorbence imaging of capillaries, , fluorescence imaging of capillaries, , HPLC glass columns, and TLC plates, offer the opportunity to study the separation as it develops. Imaging can also be performed across rather than along the capillaries, which allows simultaneous detection of 100 or more capillaries laying side by side …”

Direct Imaging of the Stepwise Elution Process in High-Performance Liquid Chromatography

“…In isocratic elution, the square of the bandwidth is proportional to the migration distance in the column. 14 According to the data shown in Figure 5, a nearly linear dependence of the square of the bandwidth on the migration distance also applies in the stepwise elution mode. These results show that the band broadening depends on migration distance rather than migration time.…”

“…In isocratic elution, the migration distance had a good linear relationship with the migration time, and the slope is the apparent migration velocity. 14 In the case of stepwise elution, the migration velocities of solute bands were changed to another constant velocity after the inflection points. Table 1 shows the migration velocities calculated from in Figure 3 and the isocratic elution by the second eluent.…”

“…The migration distance, d i , at inflection time, t i , can be obtained by substituting t i , d i in eqs 3 and 5, respectively: This is eq 2. The migration velocity, K, relates to the conventional capacity factor, k′, as follows: 14 Upon substituting eq 11 into eq 2 or 10, we have Further rearrangement could be done by substituting u in eq 1 into eq 12:…”

“…To get a clearer visualization of the problem, we developed a video image analyzing system for liquid chromatography . Video detection methods have been previously used in separation sciences as an alternative to two-dimensional densitometers, − as a detector for DNA molecular movement in pulse field gel electrophoresis, and in capillary electrophoresis. − In the present work, we investigated the dynamic aspects of band migrating processes in HPLC and estimated the movement of the solvent front in a stepwise elution mode using video imaging techniques.…”