Solvent suppression techniques for coupling of size exclusion chromatography and 1H NMR using benchtop spectrometers at 43 and 62 MHz

The characterisation of polymeric materials in their full complexity chain length, monomeric composition, branching and functionalization is a tremendous challenge best tackled by tailored multi-dimensional coupled analytical detection techniques. Herein, we focus on the improvement an affordable but information rich 2D-method for polymer analysis: online hyphenation benchtop 1H NMR spectroscopy with size exclusion chromatography (SEC). main benefit this approach correlated length (SEC) to chemical composition (1H NMR). Our setup combines SEC onflow spectrometer at 43 or 62 MHz shift resolution as robust detector. A detailed comparison two instruments included considering, that only instrument equipped dedicated z-gradient enabling pulse sequences such WET. method very low concentration species interest after chromatographic separation. At typical conditions, analyte dilution typically more than factor 1000:1 protonated solvent. Therefore, efficient solvent signal suppression needed. In article, several are explored like WET, WEFT, JNR simple one-pulse – some first time hardware. By choosing optimal method, strength ratios 1:1 better achievable flow. To illustrate broad range possible applications, three cases proximity (no overlap, partial overlap) discussed using polymers (PS, PMMA, PEMA) solvents (chloroform THF). For each case, methods compared evaluated set numerical criteria (analyte broadening, suppression, remaining width).