A stop-flow sample delivery system for transient spectroscopy.
David BuhrkeJeannette RufPhilipp J HeckmeierPeter HammPublished in: The Review of scientific instruments (2022)
A stop-flow sample delivery system for transient spectroscopy is presented, which is, in particular, suited for laser-based instruments (quantum-cascade lasers or amplified femtosecond lasers) with excitation pulse repetition rates in the range 10-100 Hz. Two pulsing micro-valves are mounted onto a flow cuvette designed for transient IR spectroscopy, which is integrated into a flow cycle driven by a peristaltic pump. The performance of the system is demonstrated with transient IR experiments of the trans-to-cis photoisomerization of a water-soluble azobenzene derivative. The sample stands still when the micro-valves are closed and is pushed out from the probe beam focus on a 1 ms timescale when opening the micro-valves. The setup is extremely sample efficient. It needs only small sample volumes, and at the same time, it enables excitation of a large fraction of molecules in solution.
Keyphrases
- water soluble
- cerebral ischemia
- aortic valve
- high resolution
- single molecule
- solid state
- aortic valve replacement
- mass spectrometry
- molecular dynamics
- ms ms
- energy transfer
- coronary artery disease
- heart failure
- blood brain barrier
- living cells
- transcatheter aortic valve implantation
- subarachnoid hemorrhage
- patient reported outcomes
- ejection fraction
- aortic stenosis