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The development of high-performance benchtop NMR spectrometers provides a practical and information-rich way to monitor on-line/in-line the progress of chemical reaction. NMR provides not only the structural information about the different chemical species involved in the reaction but also quantitative information about the concentration of reactants and products. By following the conversion in real time, …

Monitoring a Claisen-Schmidt Condensation Reaction by NMR in the teaching Class Read More »

Together with sensitivity, resolution is one of the most important quality parameters determining the performance of an NMR spectrometer. By definition, the resolution of a spectrometer is determined by the homogeneity of the magnetic field generated by the magnet and it specifies what is the narrowest possible linewidth that can be measure in the spectrum. …

Resolving up to 5J with the ULTRA high resolution of the Spinsolve 80 MHz Read More »

The knowledge of the assay of a substance is crucial information and of interest in many applications. For example  in pharmaceutical or chemical laboratories, in the production of reference materials, or to follow the conversion of reagents in reactors. In the past decades quantitative nuclear magnetic resonance spectroscopy (qNMR) has been established as a standard …

Quantitative NMR with internal standard on a Spinsolve benchtop NMR spectrometer Read More »

In order to combine the properties of different homopolymers it is possible to either synthesize block-copolymers or to make blends of the respective homopolymers. However, in many cases the homopolymers are not miscible and their phases will separate. In contrast block-copolymers which possess a covalent bond between the polymer blocks will not demix, although they …

Distinguishing copolymers and polymer blends by Diffusion Ordered SpectroscopY (DOSY) Read More »

In a previous blogpost we showed how benchtop NMR can be utilized to determine the molecular weight of polymers by using the ratio between the end-group and the backbone signals. The polymer examples shown there belong to the family of so-called homopolymers as they are made from a single type of monomer. Most commodity plastics, like …

Determination of copolymer composition by benchtop NMR Read More »

The global awareness for climate change and sustainability related topics is continuously increasing. A long-time problem in this area is related to ground water contamination, which is in the focus of industry and politics. It is known that organic solvents applied in a variety of industrial chemical processes, such as methanol (MeOH) or chloroform (CHCl3), …

Trace analysis and limit of detection (LOD) determination of solvents in water Read More »

We all know the aroma of roasted coffee beans and the taste of freshly brewed coffee or espresso, as coffee is one of the most popular drinks all around the world. For example in Germany around 150 liters are consumed per person each year. The two main utilized coffee species worldwide are Arabica with around …

Authenticity testing and caffeine quantification of coffee with benchtop NMR Read More »

One of the main parameters determining the properties of a polymer is the degree of polymerization which is directly related to the molecular weight. The degree of polymerization (DP), or number of repeating units, can be determined by comparing in the 1D 1H spectra the integral of the end-group and the integral of the repeating …

Determination of the molecular weight of polymers by end-group analysis Read More »