Is Golay’s Famous Equation for HETP Still Relevant in Capillary Gas Chromatography? Part 1: A Common View of HETP

Abstract

In this installment of “GC Connections,” we take a close look at Golay’s famous equation that most people view as relating to height equivalent to a theoretical plate (HETP) to the carrier gas flow rate or average linear gas velocity in a capillary column. We explore the original works of Golay and Keulemans. We also look closely at the original equation, the assumptions involved with its development, and the assumptions (both good and bad) that have been applied to HETP over the years. In part two, we will explore the consequences and relevance of this theory today, with temperature programming, very long (and very short) columns, high pressure drops, and vacuum outlet detectors.