An analysis system (1) for the analysis of a sample, comprises a gel permeation chromatograph (14) that is coupled with a nuclear magnetic resonance (=NMR) spectrometer. The chromatograph (14) has a gel permeation chromatography (=GPC) separating column system (6a) that is filled with porous particles (21). The NMR spectrometer is configured as a low-field NMR spectrometer (8) with a permanent magnet system (9) for generating a B0 field of the NMR spectrometer. The low-field NMR spectrometer (8) comprises a shim system (10) with which homogeneity of the B0 field of at least 0.5 ppm can be achieved in a right circular cylindrical sample volume (27) having a diameter of at least 5 mm and a length of at least 15 mm. The system permits the quantitative and qualitative chemical analysis of samples containing substances of different molecular size using a less expensive apparatus.