I am using Eurokat H column for analysis of Sugar alcohol for the first time. The column was totally new.
I used the H2SO4 aqueous solution with pH around 2. The mobile phase was used in flow of 0.1 ml/min plus column temperature of 60 C, as it was suggested. According to instruction of the column that I found from Kanuer, The column pressure should not exceed 100 bar.
Unexpectedly, the pressure of the column with a flow of 0.1 was found to be very high at around 80 bar. To make sure where this pressure comes from, I also checked the pressure without the column and the pressure 0 was reached. So I made sure that the high pressure of the system comes from the column and not from possible clogging in channels.
I would be greatly appreciated if some give me an advise to solve this problem. Any suggestion would be valuable
Regards
Marzieh
Dear Marzieh,
What was the solvent in which the column was shipped. Was it a polar solvent.
Have the injected solutions been filtered. For HPLC work filter each solution to be injected, with a 0.45 µm filter. For UHPLC work filter each solution to be injected, with a 0.2 µm filter.
Is a fresh guard column being used.
It may be that injected solutions contain analytes which have not been eluted off the column. Flush/backflush off analytes which are not of interest in the injected solutions. After that, during sample pre-treatment, use an efficient means of matrix reduction.
Kind regards,
Ade Kujore
Marketing
Cecil Instruments Limited
Milton Technical Centre, Cambridge CB24 6AZ
United Kingdom
email:- [email protected]
telephone:- +44 (0) 1223 420821
fax.:- +44 (0) 1223 420475
web site:- www.cecilinstruments.com
Facebook www.facebook.com/cecilinstruments
Registered Office: Unex House, Bourges Boulevard, Peterborough PE1 1NG, United Kingdom
Registered Number 909536
Follow the column maintenance instructions. The new column needs special precautions when start working (see the pamphlet with the column and follow the washing instructions carefully).
Dear Ade, I appreciate for your answer and the information,
Indeed, since the column is new, I asked the company of providing the products, about the pre-column, and they told me that this column does not have a pre-column ! (is that right ???)
It should be noted that I have not yet injected any samples and only the solvent passed through the column. And that the things which surprised me, because basically, the new columns should be free of any disturbing particles.
As you suggested, I will once again filter the solvents to see what will happen.
Could you please also explain what do you mean by " use an efficient means of matrix reduction"
Thanks a lot,
Marzieh
Dear Abdallah Hussien, Thank you so much.
You are right. I may need to repeat the instructions more carefully. Hope that these inappropriate conditions did not damage the structure of the column !
Dear Marzieh,
In order to preserve the life of the relatively expensive analytical column, a cheaper pre-column or guard column is often used, so that the injected sample may first pass through the guard column, which will filter out extraneous material.
So pre-columns or guard columns are separate columns. They have a composition similar to the analytical column, but are shorter and have larger pore sizes.
The mobile phase should be created with HPLC grade solvents, and filtered with a 0.45 µm filter.
During sample pre-treatment, matrix reduction is a process which removes as much of the sample matrix as is practical. So if for example, your sample is a diluted yogurt drink or mulberry jam, then matrix reduction would remove most of the solids which are insoluble in mobile phase.
Kind regards,
Ade Kujore
Marketing
Cecil Instruments Limited
Milton Technical Centre, Cambridge CB24 6AZ
United Kingdom
email:- [email protected]
telephone:- +44 (0) 1223 420821
fax.:- +44 (0) 1223 420475
web site:- www.cecilinstruments.com
Facebook www.facebook.com/cecilinstruments
Registered Office: Unex House, Bourges Boulevard, Peterborough PE1 1NG, United Kingdom
Registered Number 909536
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