Golay Equation Versus the van Deemter Expression

The fundamental equation underlying the performance of a gas chromatographic column is the van Deemter expression [equation (2.1)], which may be expressed as 

This abbreviated expression is often referred to as the Golay equation (43). The B term may be expressed as IDgU, where Dg is the binary diffusion coefficient 

However, the major contributing factor contributing to band broadening is the C term, in which the resistance to mass transfer can be represented as the composite of the resistance to mass transfer in the mobile phase Cg and that in the stationary phase Q  

Di is the diffusion coefficient of the solute in the stationary phase, k the retention factor of the solute, // the film thickness of stationary phase, and r the radius of the capillary column. With capillary columns, C/ is small and becomes significant only with capillary columns having a thick film of stationary phase. The Golay equation may then be rewritten as 

opt = and the value of E corresponding to this optimum linear 

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