Very strange problem with blank sample PDA Method!
Posted: Tue Jul 12, 2016 6:08 pm
I have been running a rel subs method for several months now, gradient baseline two wavelengths (lets say 240nm and 260nm) on a PDA UPLC system. I normally run a few condition columns at the start of my run to condition the column (funnily enough!) with my mobile phase, and then I enter a "Clear Calibration" line then straight into my first sample, Diluent or Blank.
Last week I forgot to enter the Clear Calibration on the sample set and now following integration of samples, I cant process the run, The processing method scans the first 240nm then shows an error saying "Cant locate 260nm processing channel" and it stops. Any attempt to select this sample in 2D and 3D channels yields the same error. But this only happens with the blank sample. When I processed the other samples from Injections using my Method Set, they converted to results for BOTH wavelengths. I cant pinpoint why this is happening.
Is it possible the lack of clear calibration functionality between the static condition column mode and first sample injection led to a delay in the 2 wavelengths being incorporated or perhaps a blank calibration curve is essential for any subsequent samples to be properly processed after data is acquired? Condition Column by default scans at one wavelength of 254nm, its almost as if the calibration curve only consists of the first wavelength for the blank sample but then kicks into 2 wavelengths for samples. It was the first run in the project and the custom fields etc and table space is normal. Can anyone help?
I have also tried:
Powering off the Lace and Instrument both manually and within "Configure System" in case there was a communication error.
Increasing table space.
Making two new PDA processing methods and putting them in my MS to process.
Making an entire NEW MS making a new instrument method and new processing method from scratch.
Checked the processing method for 260nm PDA within the MS dozens of times as well as the ins method and the sample set but nothing is awry!
Getting an admin to reset my settings and copying over the properties of another analyst to my username but to no avail.
I have run out of options so any advice is very welcome, sorry for length of post I'm trying to provide as full a picture as possible..
Last week I forgot to enter the Clear Calibration on the sample set and now following integration of samples, I cant process the run, The processing method scans the first 240nm then shows an error saying "Cant locate 260nm processing channel" and it stops. Any attempt to select this sample in 2D and 3D channels yields the same error. But this only happens with the blank sample. When I processed the other samples from Injections using my Method Set, they converted to results for BOTH wavelengths. I cant pinpoint why this is happening.
Is it possible the lack of clear calibration functionality between the static condition column mode and first sample injection led to a delay in the 2 wavelengths being incorporated or perhaps a blank calibration curve is essential for any subsequent samples to be properly processed after data is acquired? Condition Column by default scans at one wavelength of 254nm, its almost as if the calibration curve only consists of the first wavelength for the blank sample but then kicks into 2 wavelengths for samples. It was the first run in the project and the custom fields etc and table space is normal. Can anyone help?
I have also tried:
Powering off the Lace and Instrument both manually and within "Configure System" in case there was a communication error.
Increasing table space.
Making two new PDA processing methods and putting them in my MS to process.
Making an entire NEW MS making a new instrument method and new processing method from scratch.
Checked the processing method for 260nm PDA within the MS dozens of times as well as the ins method and the sample set but nothing is awry!
Getting an admin to reset my settings and copying over the properties of another analyst to my username but to no avail.
I have run out of options so any advice is very welcome, sorry for length of post I'm trying to provide as full a picture as possible..