Can I collect just the first few minutes of a run? - WKB838

ENVIRONMENT

• Empower
• Agilent
• Waters HPLC

ANSWER

If using a Waters system: Set up a runtime equaling the time you want to collect (in this example it is 4 minutes) and use the "Next Injection Delay" column to set the remainder of your run time (in this case 7 minutes) via the Run Samples window in the sample set method. Next injection delay will still continue with the full gradient, but it won't collect data. Below is an example:

ADDITIONAL INFORMATION

If this logic is applied using an Agilent system with Empower, it won't work. It is an issue with Agilent LC in the way the timing works. Waters HPLCs follow the instructions from the sample set method with regard to timing. For Agilent systems, what could be done in the sample set method is as follows :

1. Create Method Set 1 with Instrument Method 1, which would have a 4-minute gradient.
2. Create Method Set 2 with Instrument Method 2, which would have a 7-minute gradient.
3. Line 1 in the sample set method would be inject sample with a run time of 4 minutes.
4. Line 2 would be condition column with a run time of 7 minutes.

You can insert the wash step in between the sample injections. See TECN1852400.