In all previously reported examples, sample preparation requires a very specific experimental setup that can be inaccessible to some laboratories. Therefore, a more user-friendly approach regarding sample preparation and accessibility is required. Here, we show that the use of a commercial stopped-flow device connected to a freeze-quench accessory and dedicated cryogenic sample packing allows low-temperature NMR analysis of reacting solutions, with potential use for DNP magic angle spinning (MAS) approach.