The sample preparation setup is displayed in Figure . The stopped-flow device (BioLogic SFM-4000, Figure ) is equipped with three main components: (1.) four independent syringes, (2.) mixers, and (3.) spray. Up to four solutions can be loaded and then mixed in three different compartments where solutions can be aged from a minimum of 9 ms. After mixing, the resulting solution is transferred through the last mixer and the ejection delay line (EDL) to a nozzle (3.) with an internal diameter of 0.5 mm and sprayed into a 50 mL falcon tube that is filled and stored inside cold isopentane (-145 0 C) (Figure ). Cold isopentane is prepared by gradually adding liquid nitrogen under stirring in a dewar.