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Questions related from Jonathan Decenzi
I am running several matrices for sugar on the HPLC, and no matter how clear the sample looks, the pressure jumps when it gets to this particularly starchy sample. I suspect that the starch is...
03 March 2014 7,177 34 View
I have gotten the Vitamin C to stick to a C18 using methanol at 0.5 mL/min, but it always comes out in a blob when I run a food sample. I have set the UV to 243, 250 and 260 to try and phase out...
01 January 2014 8,707 26 View
At times, I have run into analytes that don't give particularly great peak shape, whether on GC, HPLC or MS. I have run methods where despite some tailing on the chromatography, we have...
10 October 2013 5,286 3 View
I have obviously gathered validation data such as linearity tests, matrix spikes, precision and even blind proficiency samples. So what would be the next step?
09 September 2013 7,103 10 View
My lab analyzes sugar in food samples using AOAC guidelines, and it doesn't take long for the chromatographic performance to decline, and there is a steady increase in backpressure with every run....
08 August 2013 6,846 5 View
I cleaned the inlet, changed the liner and septum, the flows are good, cleaned the detector, changed the jet, recut both ends and reinstalled the column. I could see a solvent peak after that, but...
08 August 2013 5,940 17 View
The work will not be for any educational purposes, this will be for my business institution. We are on a tight budget, but I also don't want to skimp too much on quality.
07 July 2013 9,999 8 View
The instrument is old, I changed a lot of the other plumbing. The pressure is fine and steady when equilibrating, then when it goes to make the injection, it just starts flowing from the needle...
04 April 2013 1,264 1 View
