{"id":1573,"date":"2019-02-27T07:44:00","date_gmt":"2019-02-27T13:44:00","guid":{"rendered":"https:\/\/www.rqmplus.com\/?p=1573"},"modified":"2025-09-03T09:14:26","modified_gmt":"2025-09-03T14:14:26","slug":"how-to-choose-gpc-column","status":"publish","type":"post","link":"https:\/\/www.rqmplus.com\/blog\/how-to-choose-gpc-column\/","title":{"rendered":"How to Choose a GPC Column"},"content":{"rendered":"\n

Gel Permeation Chromatography (GPC) is a powerful technique that provides a direct measurement of molecular weight, a critical property in characterizing natural and synthetic polymers. There is no universal GPC system with the capability to separate every polymer-based exclusively on size, so how do you choose the correct column tailored specifically for your sample?
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Choosing a Mobile Phase<\/h2>\n\n\n\n

It all starts with the mobile phase. What is your sample polymer soluble in? A polymer that is insoluble cannot be analyzed by GPC, making solvent selection paramount. For an efficient GPC separation based only on size, the optimal solvent should be strong enough to minimize the sample-column interaction.<\/p>\n\n\n\n

Don\u2019t Sacrifice on Resolution<\/h2>\n\n\n\n

When choosing GPC columns, it is essential to decide on the level of resolution desired for your samples and standards. Remember the golden rule: resolution and separation efficiency increases directly with the column\u2019s volume (pore volume). The length and internal diameter (ID) of each column should be carefully considered prior to purchasing any column set. We would suggest:<\/p>\n\n\n\n

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  1. Using a longer column, or multiple columns in series (two 30 cm in series vs. one 30 cm column)\u00b9<\/strong><\/li>\n\n\n\n
  2. Choosing a column with a larger internal diameter (22 mm vs. 7.8 mm)<\/li>\n<\/ol>\n\n\n\n

    An advantageous solution to poor resolution is to include an additional column in series to your current system. \u201cFree resolution\u201d can be obtained by increasing the column temperature or by choosing the optimal injection volume\/concentration for your system.<\/p>\n\n\n\n

    Pore Size Matters<\/h2>\n\n\n\n

    GPC utilizes a non-interactive stationary phase, composed of a porous network, allowing for an elution order based on decreasing molecular size.  There are a number of pore sizes available, and each pore size excels at separating a specific molecular weight range (Table 1).The Mixed Bed column is a linear column, and is strongly recommended for routine or unknown sample analyses. The column pore size should be chosen based on the suspected molecular weight range of the polymer being analyzed.<\/p>\n\n\n\n

    \u201cIt\u2019s Just a Phase\u2026\u201d<\/h2>\n\n\n\n

    Let\u2019s summarize what we know now:<\/p>\n\n\n\n