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- Posts: 2
- Joined: Wed May 06, 2020 6:35 pm
Using a Metrohm Compact 881 Pro IC with a Multitek drive furnace attached as the 'remote box'
We use a 5ppm phosphate scrubber solution, so when a Blank run is done we look for a 5ppm phosphate peak around 13-15 minutes. The machine has been unusable lately because the Blank printouts are terrible - dropping conductivity and background noise and no phosphate peak!
I replaced the older Phosphate scrubber solution with one I made so that I can be sure it was made correctly. I replaced the Eluent aspiration filter. (the eluent used is standard carbonate eluent - the snips from Metrohm). I detected a small air leak between the 'out' eluent degasser port and the high pressure pump, corrected the leak. I purged the valve after changing the eluent aspirator filter to rid the line of any air bubbles.
This has fixed the dropping conductivity, low baseline, and a good bit of noise.
But where oh where is my phosphate peak???????
In November a direct injection calibration was done for the ions we look at: F-, Cl-, and our reference phosphate. I don't believe calibration is the issue. We run the IC at a constant 26C temperature.