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- Posts: 1
- Joined: Thu May 18, 2023 10:46 pm
- Location: United States
Hello, I am working with a team testing residual solvents within consumer products. We test for 28-analytes using an Agilent 7697A Headspace sampler and a 7890B GC system attached to a 5977B MS.
Our current set up includes a 624plus column at 60 meters, .25mm ID, and 1.4um film thickness.
A few days ago we came across an issue with our QC recoveries immediately after a fresh recalibration. Our accuracies were well below acceptable range (70-130%) for all analytes aside from the heavier xylenes at the end of our method, although even these were at the lower end of acceptability. We noticed that an initial CCV would recover low, but additional CCVs ran in sequence would increase in recoveries. For example, Acetone increases from 36% to 59% to 62%.
We've replaced the injection port, loop, and transfer line with the issue persisting. Any familiarity with troubleshooting this is greatly appreciated.
Our current set up includes a 624plus column at 60 meters, .25mm ID, and 1.4um film thickness.
A few days ago we came across an issue with our QC recoveries immediately after a fresh recalibration. Our accuracies were well below acceptable range (70-130%) for all analytes aside from the heavier xylenes at the end of our method, although even these were at the lower end of acceptability. We noticed that an initial CCV would recover low, but additional CCVs ran in sequence would increase in recoveries. For example, Acetone increases from 36% to 59% to 62%.
We've replaced the injection port, loop, and transfer line with the issue persisting. Any familiarity with troubleshooting this is greatly appreciated.
