Anaerobic Operation
The anaerobic accessory equips all SX series with a high performance bench-top anaerobic capability. Anaerobic conditions are maintained using the purging manifold that forms the main part of the accessory. This unit mounts over the lower section of the drive syringes and is purged with a steady stream of nitrogen to maintain an oxygen-free environment in the region between the syringe-pistons and the syringe-barrels. This prevents oxygen diffusion across the syringe-tips and contamination of the sample.
Three-Way Valves
Three-way valves are also provided to enable anaerobic samples to be introduced to the sample handling unit without coming into contact with the outside environment (air). A full protocol for anaerobic sample introduction is provided.
Glove Box Installation
For the most challenging anaerobic measurements some users prefer to mount the instrument sample handling unit inside a nitrogen environment glove box. Applied Photophysics provides tailor-made interface solutions for glove box installations which typically involve a longer cable set and fibre-optic light guide.
Anaerobic Accessory vs. Glovebox
Applied Photophysics knows that some sample types are finicky – some small molecules, catalysts, or metalloproteins are prone to oxidation when prepared under atmospheric conditions. The flow circuit material within the SX20 is composed of polyether ether ketone (PEEK), allowing for the rapid removal of dissolved oxygen by purging with a dithionite solution. Only the syringe tips are made with polytetrafluoroethylene (PTFE), which is more difficult to fully purge of oxygen.
For particularly air-sensitive reactions, we recommend that the stopped-flow instrument is placed inside a glovebox. The rule of thumb is that if the sample(s) must be prepared in the glovebox, the instrument should be inside a glovebox.
For less sensitive reactions, we offer an anaerobic accessory: a purging manifold that mounts over the lower section of the instrument’s drive syringes. A steady stream of nitrogen prevents oxygen diffusion across the syringe tips and sample contamination. We also provide a set of three-way valves that allow anaerobic samples to be introduced to the sample handling unit without contact with air.