Amines can be difficult to analyze by GC, since they are active and adsorb to surfaces within the chromatographic system, including the inlet liner and the column. This leads to loss of compound response, and peak tailing. While deactivations can help to mitigate these effects, the quality of deactivations varies. Primary amines are especially difficult, due to their susceptibility to interact with active acidic sites like silanols, commonly found in liners and columns.<\/p>\n\n\n\n
Restek offers a base deactivation for both liners and columns, designed to passivate glass surfaces with basic sites, lessening the chances of adverse reactions with amines and other basic compounds. As you may be aware, Restek launched Topaz inlet liners in 2017 as our newest premium liner deactivation. One question that has come up a few times is \u201cHow do Topaz liners compare to base deactivated liners for analysis of difficult amines?\u201d A study was conducted to compare responses of active bases on the two deactivation chemistries.<\/p>\n\n\n\n
The method conditions shown in Table 1<\/em> were used for the comparison. A mix containing primary, secondary, and heterocyclic amine groups, as well as an ethanolamine and an aniline, was evaluated on Restek\u2019s base deactivation and Topaz deactivation (See Figure 1<\/em>). Two different concentration levels were tested on each liner. A total of 7 liners from each deactivation were evaluated. Liners were single taper with wool tested in splitless mode, as this provides a very rigorous test of the deactivation.<\/p>\n\n\n\n Table 1<\/em>: Method conditions for testing liners for amine response.<\/p>\n\n\n