Chromatography Forum

Hi,

Everyone knows cleaning procedures for GC or LC. Replace liners, cut small part of columns or wash with 10% and 90% organic/water solutions etc.

I want to ask - how about acceptance criteria for cleaning of chromatographs? Next analysis blank solution does not give full answer to this question. For example, phosphoric ions, ion pair reagents, high boiling point

I think there *is* no "full answer". It will depend on the specific method you are running. If you run the method and meet the system suitability criteria for that method, then it is suitable for the purpose.

http://www.chromatographyonline.com/why-system-suitability-tests-are-not-substitute-analytical-instrument-qualification-or-calibration-0

System suitability is for system readiness for current analysis. SS not answer to unexpected goust peeks which flushed out from system.

Waters Qualification include baseline drift, S/N analysis, peak height analysis.
If system is dirty, we can expect failure to qualification, or verification.

So this is my thinks why system suitability can not be an answer to system cleansed.

I definitely agree that System Suitability does not substitute for Qualification (ask anyone who has taken our Troubleshooting courses!) --

-- but "Qualification" does not address general instrument cleaning issues. Just re-read your post:

Waters Qualification include baseline drift, S/N analysis, peak height analysis

there is nothing in that list that measures how clean the instrument is.

More to the point, there is no way to set an absolute standard for "clean"; it depends on what you are doing. As an example from my own experience, at one point in my career I was doing a lot of single-column ion chromatography (basically, ion-exchange separation with conductivity detection). HPLC-grade water gave an enormous (unsuitable) background. It turns out that the specification for water quality was based on UV cutoff; the water could (and did) have significant ionic contamination and still pass. Plain old DI water gave a much lower background, but would never have passed for UV detection.

When all is said and done, the instrument (and supplies) must be sufficiently clean for the purpose of the analysis (i.e., "suitable for the purpose").