Some questions on nanoAcquity UPLC
Answers
-
Tony:
Here are answers from the nanoACQUITY UPLC Product Manager. Let us know if you ahve further questions.
The answer to #1 is no, Waters has not programmed the difference in radii between the 10- and 6-port valve. There would also be a dispersion hit on the 10-port. We have a cut-out on the HTM where a 2nd valve could go. It was not and will not be implemented.
The answer to #2 is that the bigger the loop the larger the system volume and dispersion. We can make multiple injections up to and beyond 100 uL using a smaller loop and trapping column. We have not tested a larger syringe with nanoACQUITY. Could you try this instead?
The answer to #3 is that the ASM functions as 2 isocratic pumps. Only one is under flow control and is used for nanolockspray addition.
The other side is not under flow control and is used for a different trapping eluent or to elute the pepsin column in HDX. Many people like to use TFA to trap and formate for gradient elution.Pat YoungWaters Product Mgt0 -
Dear Patricia,
Here are answers from the nanoACQUITY UPLC Product Manager. Let us know if you ahve further questions.
The answer to #1 is no, Waters has not programmed the difference in radii between the 10- and 6-port valve. There would also be a dispersion hit on the 10-port. We have a cut-out on the HTM where a 2nd valve could go. It was not and will not be implemented.
Toby: For the cut-out on the HTM, can it fit for and control the 6-port valve?
The answer to #2 is that the bigger the loop the larger the system volume and dispersion. We can make multiple injections up to and beyond 100 uL using a smaller loop and trapping column. We have not tested a larger syringe with nanoACQUITY. Could you try this instead?
Toby: Because the cusotmer uses the orbitrap software to control the nanoAcquity UPLC, can it also do the multiple injection?
The answer to #3 is that the ASM functions as 2 isocratic pumps. Only one is under flow control and is used for nanolockspray addition.
The other side is not under flow control and is used for a different trapping eluent or to elute the pepsin column in HDX. Many people like to use TFA to trap and formate for gradient elution.
Toby: For the pump without the flow control, does it mean that it can be used with only one flow rate or just the flow rate applied may not be stable?
Best regards,
Toby
0 -
The answer to #1 is no, Waters has not programmed the difference in radii between the 10- and 6-port valve. There would also be a dispersion hit on the 10-port. We have a cut-out on the HTM where a 2nd valve could go. It was not and will not be implemented.
Toby: For the cut-out on the HTM, can it fit for and control the 6-port valve?
Pat Young: There is no control for a second (2nd) valve of any type in the Heating and Trapping Module (HTM).
The answer to #2 is that the bigger the loop the larger the system volume and dispersion. We can make multiple injections up to and beyond 100 uL using a smaller loop and trapping column. We have not tested a larger syringe with nanoACQUITY. Could you try this instead?
Toby: Because the cusotmer uses the orbitrap software to control the nanoAcquity UPLC, can it also do the multiple injection?
Pat Young: Waters ships the nanoACQUITY UPLC System with the version (v) 1.41 driver. V 1.41 has many new features; one is the ability to make repetitive injections on to a trapping column, independently of injection loop volume.
As an example: if MassLynx commands a 30 uL injection volume and the nanoACQUITY Sample Manager (SM) was calibrated with a 10 uL sample loop, the SM would inject the 30 uL volume on to the trapping column. The SM would do this by injecting up to 80% of the loop volume at a time (8 uL in this case) until the entire commanded volume had been loaded on to the trapping column. In our example, this would be three (3) injections of 8 uL (to make 24 uL- on column) and the last injection would be 6 uL, for a total of 30 uL.
It is important to remember this is effective with column trapping only. We load the trapping column while the HTM valve in the “waste” position. This allows compounds of interest to bind in the trapping column while unwanted solutes go to waste. Then we change valve state in the HTM to bring the analytical column on-line. Compounds of interest can then elute from the trapping column and re-focus on the analytical column gradient elution.
Note: this capability resides in version 1.41. This is a nanoACQUITY driver- not for use with ACQUITY or ACQUITY H-class.
At this time, Xcalibur runs with the nanoACQUITY version 1.30 driver. This version does not support multiple injections. ThermoFisher Scientific has the v 1.41 driver and plan to add it to a version of Xcalibur. Please contact ThermoFisher Scientific for additional information.
The answer to #3 is that the ASM functions as 2 isocratic pumps. Only one is under flow control and is used for nanolockspray addition.
The other side is not under flow control and is used for a different trapping eluent or to elute the pepsin column in HDX. Many people like to use TFA to trap and formate for gradient elution.
Toby: For the pump without the flow control, does it mean that it can be used with only one flow rate or just the flow rate applied may not be stable?
Pat ...
0
