ABSTRACT
Many authors have frequently reported in the literature on the investigation of GPC eluents with several detectors working accord ing to different measuring principles. This multiple detection en ables information concerning the chemical heterogeneity, the differences in long chain branching when molecular size detectors are employed and allows the measurement of the absolute molecular weight range without previous calibration.
As in most cases, the multiple detection is effected in cells being spaciously separated, thus the dead volume of the connecting capillaries has to be taken into consideration in the evaluation. In spite of the exact determination of this geometric dead volume the interpretation of the measurements leads to unsatisfactory results. The cause of these disturbances is that on transferring the eluents from one cell to another, changes in the peak shape occur in addition to the well known shifting by the dead volume. In the pre sent paper this effect has been demonstrated by means of experimen tal examples. It has been tried by means of some models to describe these effects theoretically and to give instructions to optimize the real experimental conditions.
