$1\mathrm{.}22$ Using Moment Analysis to Evaluate Chromatography Column Performance On $2$

different days $2$ weeks apart for a $50cm$ long ion exchange chromatography column, a

step change in sodium chloride concentration is introduced at the column inlet in order

to evaluate the column performance. Conductivity is measured at the column outlet as a

function of the effluent volume, as shown in Table P$7\mathrm{.}22.$

TABLE P$7.22$

Determine the non$-$Gaussian HETP for each case. How do these cases compare

in terms of column efficiency? If there is a significant difference in column effi$-$

ciency between the two cases, what may be a reason for the discrepancy?