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- Posts: 156
- Joined: Wed Jul 03, 2013 1:51 am
- Location: Michigan, USA
Hi Everyone,
we have to quantify a semi-volatile amine impurity in the presence of bulk quantity of another semi-volatile amine. We need to make sure that the analyte is present as the free base. Which may or may not be the case.... HPLC is not an option for convoluted reasons.
To ensure that the free base is present, we are adding excess DBU base. We are seeing a nice peak. The lab tech tried pyridine first but that is too weak of a base and we saw no peak. So far so good.
However, there is NO DBU peak which worries me. Where did it go? I am not sure what the expected RT would be.
DO you have experience with using DBU to ensure analyte as the free base? We are doing liquid injection. I know this is well-established in HS.
Would you recommend using another small base rather? The analytes' pKas range from 8-10.
Thank you very much in advance!
Arne
we have to quantify a semi-volatile amine impurity in the presence of bulk quantity of another semi-volatile amine. We need to make sure that the analyte is present as the free base. Which may or may not be the case.... HPLC is not an option for convoluted reasons.
To ensure that the free base is present, we are adding excess DBU base. We are seeing a nice peak. The lab tech tried pyridine first but that is too weak of a base and we saw no peak. So far so good.
However, there is NO DBU peak which worries me. Where did it go? I am not sure what the expected RT would be.
DO you have experience with using DBU to ensure analyte as the free base? We are doing liquid injection. I know this is well-established in HS.
Would you recommend using another small base rather? The analytes' pKas range from 8-10.
Thank you very much in advance!
Arne
