Running samples overnight or during the weekend can help to improve the throughput of your experiments, but there are some considerations to make when leaving a system unattended. With continuous flow being the preferred way to maintain instruments, it can be wasteful to continue running solvent into a waste reservoir well after the experiment has finished. Another worry is the solvent reservoir running empty and columns running dry. For these reasons, we strongly recommend the Wyatt Orbit™ as a way to control when your mobile phase is directed to the waste (during sample runs) and when it should be recycled to reduce solvent consumption.
If you don’t have a Wyatt Orbit or solvent recycling system, another option is utilizing Wyatt’s HPLC Service software. HPLC Service allows ASTRA® to gradually reduce the flow rate of your HPLC system at the end of the sequence. This helps conserve solvent while keeping the system under constant flow.
You also need to consider the state in which you leave your Wyatt detectors. Every ASTRA installation comes with several system methods, called utilities, that can be customized for your instruments and run at the end of a sequence to turn off the laser, run the COMET, or even purge your Optilab. These can be found in the system folder under the System > Methods in a Utilities folder under each instrument type.
For example, under the System > Methods > Light Scattering > Utilities, there are options for both running the COMET and turning the laser off for a HELEOS or TREOS. Similar utilities are available for the microDAWN, ViscoStar, and Optilab.
System methods are locked for editing but can be saved as a new method to include your physical instruments. To make a utility compatible with your system, first open the system method, set your physical instrument in the Configuration, and then save this experiment as a new method. You can now add this method to your sequence table as a utility.
With these utilities, it is easy to turn the Orbit on for solvent recycling, turn off a laser to extend laser lifetime, or even run a COMET to help keep your system clean when you are running experiments overnight or during the weekend.