We have mentioned earlier the importance of choosing and testing of the column when developing a chromatographic method.
But what should be the routine process for qualifying a newly purchased column, and keeping them in qualified state?
Background in guidelines, regulations
Since this topic is rather specific, it's not mentioned in too many places. I know only about two of them:
The EDQM guideline on Qualification of analytical columns, and the WHO's 'Good Chromatographic Practices' guideline.
What do these document require exactly?
EDQM guideline describes several different analytical methods with rational limits to initially and periodically qualify your columns.
WHO is a bit tight-lipped (Section 10.3): 'Columns should be verified on initial receipt and checked for their suitability as part of the chromatographic system, prior to use in analysis.' *
I'd like to grasp on one small word from this requirement, and let me roll out my way of thinking based on that: 'suitability'.
An efficient approach
So we have an analytical method, with properly defined system suitability test(s). We purchase the column, and we are to use it. As soon as possible, that's why we purchased it, didn't we?
So seeing WHO requirement first, what should be our verification and checking suitability? No other than our System Suitability Test!
If the SST is OK, then we can start to feed our tray with the sample solutions, that's it!
But what does EDQM say about this scenario?
In Section 7, we can read 'In-use qualification corresponds to the system suitability test for the method used. It shall be performed on a regular basis before each test and/or during the sequence of injections.'
For me, that means you don't need any other tests to perform, but the SST. You can also proceduralize that your initial SST qualifies your columns 'automatically'.
So don't bother to take your column from routine usage in order to make it qualified with a different eluent - stay with your routine environment, and monitor your column's performance through the SST values.
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* However, the document also decribes (Section 10.2) 'Columns should be purchased from approved suppliers.' So there are some thing you cannot spare: list of approved suppliers, column inventory, etc.
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