You were asked to evaluate the results of GPC analysis of PMMA (poly[methyl meth

You were asked to evaluate the results of GPC analysis of PMMA (poly[methyl methacrylate]) polymer. Separation was made on PLGel universal column (styrene-divinylbenzene 100 – 107 separation range), RI detection, and eluent – THF, calibration by polystyrene standards. Weight and number average values were calculated directly from chromatogram. Are the calculated Mwand Mn values, correct? Explain why.
2/ You are separating benzene, toluene and ortho-nitrophenol on RP column with acetonitrile/water as eluent. How the variation of the eluent composition (% of acetonitrile in water) will affect the selectivity between benzene and toluene and between o-nitrophenol and benzene? Explain.