Question $3$

a$)$ Define the following terms

i$.$ Isocratic elution

ii$.$ Splitless injection

iii. Total ion chromatogram

b$)$ Indicate the order in which the following compounds would be eluted from an HPI $r.$ column containing a reversed$-$phase packing: acetone, dichloroethane, acetamide.

c$)$ Explain your answer to question $($b$)$ above

d$)$ Two components in an HPLC separation have retention times that differ by $22s.$ The first peak elutes in $10\mathrm{.}5$min and the peak widths are equal. Calculate the minimum number of theoretical plates needed to achieve a resolution of $0\mathrm{.}50$

e$)$ Describe the principle of operation of a thermal conductivity detector $($TCD$)$ as used in gas chromatography

f$)$ A chromatogram is obtained with the following components and corresponding retention times

$\backslash$table$[[$Component$,$Retention time $(\frac{L_L}{m}in)$