Chromatography Forum

I am having trouble setting up an instrument method and sample set. Currently, I have no problem with my instrument method when I do single injections. It starts, runs and stops as it should. However, when I set up a sample set, the method starts and runs the first injection, but then I receive an "instrument failure" notice and must "abort and continue on next line" with each new injection. The only way I've found around this is to remove the "0.0 flow" line from my instrument method. However, when I do this, the injections proceed with no problem, but at the end of the method, the pump does not shut down. At this point, I am unable to do runs overnight and such, which is the point of the autosampler! Any advice/help would be much appreciated!

I dont what data system you are using but these are 2 things to try.

instead of zero flow, make it 0.01 mL/min
or
Make a new isocratic instrument method that has zero flow and run it as the last line in your sample set (i.e. a shutdown method).

AA

I don't know if this changes anything, but we've got the following setup:

Waters 490E multiwavelength detector
Waters 510 Pumps
Waters 717 Autosampler

We're running Empower Pro software.
Thanks for the suggestions!

I think you can use your method as a gradient, with the last line a flow of 0.
But you should make the time of your last line long enough (say 5 minutes more than the normal runtime).
Only your last injection should run the entire gradient. (Or even not, your HPLC will continue the gradient if there isn't a further injection).

Ace

^ same deal w/ detector events. You may be using one to shut off your lamp, make sure it doesn't shut off the lamp until ~5 min. after data collection ends for last sample.

One of the easiest ways is to create a STOP method. In the instrument method, you just use isocratic mode and use 0.00 ml/min as flow rate. You put this into a Method set.
The last line of your sample set, you should use "condition column" as function, used the STOP method as method to use, and use e.g. 1 min as run time. So at the end of your sample set, the stop method is exectuted. The method can also include the shut down of detectors etc.
I use this for year and had not trouble with it.
I hope this helps.

So now that I've set up a stop method and switched my last method step to 0.01ml/min, I can no longer get the sample set to switch injections. I've tried generating a new instrument method and sample set with each set up, but to no avail. Is this just a bug with the software or am I missing something?