In this article, we’ll take a closer look at some of the potential adjustments related to the column.
In the first two parts of this series, we took an overview of the concept (Part 1) then at specific guidelines for mobile-phase adjustment (Part 2). This article takes a closer look at some of the potential adjustments related to the column.
Column Length
The guidelines for adjustments to the column length are the same for the European Pharmacopoeia (EP) and the United States Pharmacopoeia (USP), as summarized in Table 1 – a change of ±70% in column length is allowed. For example, let’s consider the most popular column size, 150 x 4.6 mm i.d. This guideline would allow 70% x 150 = 105 mm of length adjustment. Thus, any column in the 45 to 255 mm range would be allowed. Of course, only certain column lengths are available, but these limits allow for a change to most of the common column lengths: 50, 75, 100, 150, and 250 mm.
To view the full article complete the form below: