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Comparing cleanup methods for biological samples
Posted: Mon Jul 18, 2016 6:32 pm
by j_wells1
Can someone explain the differences in applications for the following techniques and in what situations each would be most optimal? In particular, I would like to know if some of the other techniques listed can substitute for solid phase extraction in the interest of saving time.
centrifugal spin filters
syringe filters
solid phase extraction
column guards
precolumn filters
Thanks!
Re: Comparing cleanup methods for biological samples
Posted: Mon Jul 18, 2016 6:45 pm
by GOM
Hi
Welcome to the forum
What is your sample, what are the analytes and what instrumentation are you using or have available?
Regards
Ralph
Re: Comparing cleanup methods for biological samples
Posted: Tue Jul 19, 2016 7:17 pm
by j_wells1
For the particular project I am working on the sample is serum, analyte is a small molecule and test method will be LC-MS. But my question pertains to various test methods and analytes in general.
Re: Comparing cleanup methods for biological samples
Posted: Wed Jul 20, 2016 4:50 pm
by X
Is your molecular acidic, basic or neutral? and the polarity? all these info help us suggest the appropriate sample prep method.
Re: Comparing cleanup methods for biological samples
Posted: Wed Jul 20, 2016 5:00 pm
by tom jupille
centrifugal spin filters
syringe filters
solid phase extraction
column guards
precolumn filters
In general:
- "Filters" as a class are designed to take out particulate matter. They do nothing to clean up the sample in a chemical sense.
- Column guard columns/cartridges are designed to retain strongly bound chemical compounds which would otherwise stick to (and alter the chemistry of) the analytical column. I like to think of them as a replaceable inlet end to my column.
- Solid phase extraction (SPE) is a newer name for what used to be called "open column chromatography". It can be used to selectively retain/not-retain compounds of interest to separate them from junk in the sample. It can also be used to concentrated dilute samples.
Can the other approaches replace SPE? The most general answer is "probably not", but that depends on why SPE was used in the first place, so you need to go back to the method development notebook.
Re: Comparing cleanup methods for biological samples
Posted: Wed Jul 20, 2016 5:29 pm
by GOM
In addition to the above very helpful answers
Your query
centrifugal spin filters
syringe filters
solid phase extraction
column guards
precolumn filters
can be roughly categorised as
Sample pre-treatment before injection
centrifugal spin filters
syringe filters
solid phase extraction (see Tom's summary)
and treatment after injection
column guards
precolumn filters
Out of interest - what is the "small" molecule?
Regards
Ralph