We need your help about the product below:
Product Name: Mupirocin Ointment BP
Test: Related substances
Subject: Guard Column
In Related substances, it is written : When the chromatograms are recorded under the prescribed conditions the retention time of mupirocin is about 13 minutes.
Column: Zorbax C8 7µm, 250 x 4.6mm fitted with a stainless steel guard column packed with the same material.
Without Guard Column, the retention time of Mupirocin is about 7.1 minutes.
What are the dimensions and brand of the Guard Column to be used to obtain retention time of mupirocin at about 13 minutes.