By Anonymous on Wednesday, March 31, 2004 - 01:46 pm:
I have just recently decided to try the JT Baker cation exchange SPE cartridges, and much to my surprise, they get completely clogged after a very small sample volume, some even become blocked before the conditioning solvents are passed through. I am using HPLC grade solvents, and I can see no reason why this should be happening. If anyone has had this experience before, or could offer a suggestion as to why this may be happening it would be greatly appreciated.
By Chris Pohl on Saturday, April 3, 2004 - 01:18 am:
What is the nature of and pH of your conditioning solvents?
By Anonymous on Monday, April 5, 2004 - 03:15 pm:
The pH is 3.3 and the buffer is salicylic acid and sodium salicylate, diluted with Nanopure water.
By Chris Pohl on Monday, April 5, 2004 - 08:13 pm:
I can't be sure without a bit of experimentation with salicylate but one possible explaination would be that the cation exchange catridge is in the hydrogen form. Salicylic acid isn't all that soluble in water and a cartridge in this form would convert it to salicylic acid. This could be what's clogging the pores. Try sitching to another buffer or at least conditioning first with NaCl solution to see if this helps.