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Method 525.3 UCMR4
Posted: Fri Aug 25, 2017 4:55 pm
by elgoetzman
Is anyone running method 525.3 for UCMR4? I am having issues with low recoveries of surrogates in the extraction. Does anyone have any suggestions on the extraction procedure??
Re: Method 525.3 UCMR4
Posted: Fri Aug 25, 2017 8:55 pm
by James_Ball
elgoetzman wrote:
Is anyone running method 525.3 for UCMR4? I am having issues with low recoveries of surrogates in the extraction. Does anyone have any suggestions on the extraction procedure??
We are running this method, currently have the new PT sample in house in process.
Are you getting low recoveries on all surrogates, or only on certain ones?
I found if you over dry you can lost the Benzo[a]pyrene-d12 and if the extract is too wet when eluted you will have low recoveries on the 1,3-Dimethyl-2-nitrobenzene.
Re: Method 525.3 UCMR4
Posted: Fri Aug 25, 2017 9:21 pm
by elgoetzman
Are you running manual SPE or do you have a robotic system? Any chance you could type out your steps??
Re: Method 525.3 UCMR4
Posted: Wed Aug 30, 2017 5:45 pm
by James_Ball
I am doing manual extraction and following the method exactly as written for the Waters HLB cartridges. We have also done the extraction using C18 cartridges and we get comparable results.
Definitely include the rinses of the bottle with the solvents. You end up with a little more water in the extracts that has to be removed, but the analytes do tend to stick to the glass and transfer tubes and the solvent rinse will pull them out well.
Re: Method 525.3 UCMR4
Posted: Tue Sep 05, 2017 1:17 pm
by Bigbear
We freeze or extracts before drying. It helps in not transferring water to the drying tubes.