Jamie: You are the first person I know interested on it.
I have also damaged 2 columns and I'm working with the third one.
It seems that, due to the alkalinity of eluent, proteins precipitate clogging the inner filter of the column.
I have tried to overpass this issue washing with citric acid 0.5 %w/v in water at the end of each day.
The problem was that high water content in eluent takes to really high pressures. So, to clean the column a 5 hours program.
It works but anyway I had an increase on working pressure smaller than the previously observed but always positive.
Finally I decided to install a precolumn of the same phase and cleaning the system with 50:50 water/ACN plus 0.1% v/v of Trifluoroacetic acid.
My idea was that if I have a clogging, to wash only the precolumn that should be easier.
But the procedure works so well that I have not had to dismount the column. I have not observed any pressure increase in my last four runs since I begun working with TFA. (two months ago)
My eluent is 20:80 water/ACN plus 0.2% of Triethylamine.
Next Monday I will post here the program I'm using.
About validation:
My needs are Fructose, Glucose, Succrose, Maltose and Lactose.
Separation between Maltose and Lactose is bad. It does not reach baseline in my last column.
Happily on my samples I never have both of them in the same sample.
Another issue, natural orange juice (not coming from concentrates) present a peak coeluting with maltose one.
Linearity is very good for 1 to 20 grams/liter, R2 better than 0.9995 and individual residuals smaller that 5%.
I work with RI detection, Flow 1 ml/min, column and detector kept at 35°C. sensitivity 256 (Waters RI), injection volume 10 µl.
Intermediate precision looks good but I can't give you a RSD value, not yet.
I can tell you that I have participated in interlaboratory test on wines, honey, soft drinks and liquors with good results.
I Understand that I still have some work to do on sugars, but I haven't had time to dedicate to that subject.
If you need further info ....
Regards
Guillermo
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