Fast GC Solution to Quantify Volatile Amines in Pharmaceuticals

Researchers from Merck and Agilent Technologies have developed a simple and fast generic gas chromatography–flame ionization detection (GC–FID) method for the quantitation of volatile amines in pharmaceutical drugs and synthetic intermediates (1).

Among the most frequently used compounds in pharmaceutical chemistry, volatile amines offer chemists the ability to control the pH of reaction mixtures and improve product yield because of their basic properties and low boiling point. However, the selection of the “optimal” amine for a particular production also becomes a bottleneck in synthetic route development process. Many hours are devoted to the development of new analytical methods for the quantitation of residual amine content prior to each analysis session. Hours and resources that could be focused elsewhere if an alternative option existed.

This issue has been well documented with a wide spectrum of extraction procedures already existing for each separation technique. However, most require detailed sample preparation and specific instrumentation so do not address the time issue they were intended to solve. Furthermore, many of the procedures were specific and focused on a narrow group of amines, lacking the potential to be used universally. The added speed with which chemists can generate accurate and quality data with generic or more universal chromatographic methods has led to their popularity in recent years and the need for such procedures in the production of pharmaceuticals.

The method developed by researchers analyzes over 25 volatile amines and other basic polar species in a single 16-min chromatographic run using conventional and readily available GC–FID instrumentation and using either He or H₂ as a carrier gas.

The validation experiments performed showed excellent sensitivity, precision, linear correlation, and accuracy for all the amines. Researchers also believe the method can be used as an effective starting point for solving challenging separations and analysis of volatile polar species beyond the list of amines described in the study.

Reference

1.   G.C. Graffius et al., J. Chromatogr. A1518, 70–77 (2017).