No of plates decreasing during analysis of residronate sodiu

[vishall79]

Hi,
I am doing analysis of residronate sodium as per USP. But dusring analysis it is observed that the no of lates of column are decreasing sharplt (50%). I tried washing the column, it worked for some time but later the same case repeated. Please help.

[tom jupille]

If the column returned to its original efficiency, that implies that some garbage from the sample was accumulating on the column. The most straightforward option is to wash the column regularly. Another possibility is to improve the sample prep/cleanup. A third is to use a guard cartridge.