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- Posts: 2
- Joined: Wed Jun 18, 2008 5:42 pm
Our lab has recently changed software to just the GC software which Agilent offers. We are running GC (FID) on a 6890 and using chemstation software version B.01.01.
We are a hazardous waste facility and have a lot of compounds to look for, over 90. Our method is just under 20min long. One barrier we are up against is that we cannot change our method, just not an option. When we make up our calibration curve, we use 12.5% for each of the compounds, therefore we have eight cmpds per mix. We have 12 mixes, mostly separated out by cmpd type (i.e. acetates, alcohols, ethers, esters, ketones, etc).
The problem: co-eluters in unknown samples. We receive in a sample which could potentially have a variety of components. The overall method has all 90+ compounds in it. When the software recognizes a peak at a particular retention time, it assigns a compound name. Sometimes this is in error. For example, we have DMF, Ethyl Lactate (EL), and Ethylene Glycol (EG)which all elute at nearly the same time. The software will call a peak DMF, and I know that it is EG. What I don't know is how to make it say that and then give me the appropriate percentage based on that compounds response factor etc.
One idea we had was to create a method for each of the potential waste streams, but that is almost absurd because we have well over 100 options. Additionally, even that wouldn't eliminate all co-eluting compounds. Currently we are going into our calibration table and deleting the compounds we know are not there, re-integrating, then not saving the changes.
Any help would be great.
Thank you very much,
Rachael
We are a hazardous waste facility and have a lot of compounds to look for, over 90. Our method is just under 20min long. One barrier we are up against is that we cannot change our method, just not an option. When we make up our calibration curve, we use 12.5% for each of the compounds, therefore we have eight cmpds per mix. We have 12 mixes, mostly separated out by cmpd type (i.e. acetates, alcohols, ethers, esters, ketones, etc).
The problem: co-eluters in unknown samples. We receive in a sample which could potentially have a variety of components. The overall method has all 90+ compounds in it. When the software recognizes a peak at a particular retention time, it assigns a compound name. Sometimes this is in error. For example, we have DMF, Ethyl Lactate (EL), and Ethylene Glycol (EG)which all elute at nearly the same time. The software will call a peak DMF, and I know that it is EG. What I don't know is how to make it say that and then give me the appropriate percentage based on that compounds response factor etc.
One idea we had was to create a method for each of the potential waste streams, but that is almost absurd because we have well over 100 options. Additionally, even that wouldn't eliminate all co-eluting compounds. Currently we are going into our calibration table and deleting the compounds we know are not there, re-integrating, then not saving the changes.
Any help would be great.
Thank you very much,
Rachael
