This is a good general usage recommendation, but what about for specialty columns? For instance, I sometimes use phenyl columns or HILIC columns. About 80% of what I analyze uses either C8 or C18 Reverse-phase columns, and I would definitely employ this cleaning method, but is there a better cleaning format for the lesser used types of columns?
I’m using RP18 250 cm column with 90% 1%acetic acid and 10%MeOH on gradient where B maximum is 65%. After about 80 hours of constant use, I found peaks are moving forward for about half minute, even for standards. Can you tell me the reasons and solution. Column can work between 1-9 pH, n A phase has pH around 3.5
you're probably not equilibrating your column long enough. you might want to hold it at B longer at the end of the run or even kick it up higher and then when you bring it back to the starting conditions - let that go for a bit before ending the run.
Can you write a detailed program to clean column C18 with this method (95% water and 5% methanol for 10 column columns. Do a gradient of 5 to 95% methanol for 5 column volumes. Hold 5% water and 95% for 10 column volumes?) Tks Note: I use pharmaceutical analysis with HPLC Dionex Ultimate 3000 autosampler and Water E2695 autosampler. Example: I used ACN: KH2PO4 0,01M (40:60) pharmaceutical analysis, so How I can clean column C18 with this method?
You need to remove your current mobile phase and replace with methanol and water. It's important to remove the salt in your column. Hopefully you have a binary or quaternary pump where you can do a gradient. You first start with a hold of 5:95 methanol to water. Then you do gradient. Finally you hold 95:5 methanol to water.
Do not follow this video. Always follow the column manufacturers manual and call their technical support if you have specific application questions. Anyone who would tell you to reverse flow through a HPLC column is basically telling you to piss way $1500. Source: I'm a field service engineer for Thermo Fisher and I work in IC/LC chromatography.
Hey Daniel, this is for a reverse phase column and this is in the column care guide that comes with the column. Yes, you are right that this does not apply to all columns but it does apply to this column as it is reverse phase.
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Excellent video
Thank you very much!
Really helpful thankss
This is a good general usage recommendation, but what about for specialty columns? For instance, I sometimes use phenyl columns or HILIC columns. About 80% of what I analyze uses either C8 or C18 Reverse-phase columns, and I would definitely employ this cleaning method, but is there a better cleaning format for the lesser used types of columns?
I have the exact same question too
I have purchase new hplc c18 colums. I want to know how to use a new colum??. Or just start using it for routine analysis. I want your say on this
how about the flow rate of 10% Methanol???
I’m using RP18 250 cm column with 90% 1%acetic acid and 10%MeOH on gradient where B maximum is 65%. After about 80 hours of constant use, I found peaks are moving forward for about half minute, even for standards. Can you tell me the reasons and solution. Column can work between 1-9 pH, n A phase has pH around 3.5
you're probably not equilibrating your column long enough. you might want to hold it at B longer at the end of the run or even kick it up higher and then when you bring it back to the starting conditions - let that go for a bit before ending the run.
Is 100 present ACN not good enough for flushing columns?
not for all situations no.
Can you write a detailed program to clean column C18 with this method (95% water and 5% methanol for 10 column columns. Do a gradient of 5 to 95% methanol for 5 column volumes. Hold 5% water and 95% for 10 column volumes?) Tks
Note: I use pharmaceutical analysis with HPLC Dionex Ultimate 3000 autosampler and Water E2695 autosampler.
Example: I used ACN: KH2PO4 0,01M (40:60) pharmaceutical analysis, so How I can clean column C18 with this method?
You need to remove your current mobile phase and replace with methanol and water. It's important to remove the salt in your column. Hopefully you have a binary or quaternary pump where you can do a gradient. You first start with a hold of 5:95 methanol to water. Then you do gradient. Finally you hold 95:5 methanol to water.
@@DavidYazdi1 Tks so much
Do not follow this video. Always follow the column manufacturers manual and call their technical support if you have specific application questions. Anyone who would tell you to reverse flow through a HPLC column is basically telling you to piss way $1500.
Source: I'm a field service engineer for Thermo Fisher and I work in IC/LC chromatography.
Hey Daniel, this is for a reverse phase column and this is in the column care guide that comes with the column. Yes, you are right that this does not apply to all columns but it does apply to this column as it is reverse phase.
100 %Water is not good for column
I invite everyone to read coran the last book of god on earth and judge it