AbstractA theory has been developed for the mathematical analysis of the transient behavior of a thermoelectrogravitational electrophoresis column without reservoirs using the transport equation approach. Experimental data were obtained with a parallel membrane batch electrophoresis column to test the theory.The transient batch separation factor data obtained for a bovine albumin system under different values of the parameters (electric field strength, mobility, membrane spacing, and temperature difference) are discussed and compared with the results obtained using column transport coefficients empirically determined from steady state flow data (see Part 11). Experimental separation factors for the transient operation agree with those predicted using column transport coefficients (H and K) derived from steady flow studies, providing further support for the use of the Furry, Jones, Onsager approach to the analysis of electrophoresis columns. Failure of quantitative agreement between theory and experiment is attributed to the use of large spacings in obtaining experimental data.