Correlations between Chemical Compositions and Retention Times of Methacrylate Random Copolymers Using LC-ESI-MS.

Correlations between chemical compositions and chromatographic retention times (Rt) of methacrylate random copolymers were studied by liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). Twenty-six different polymers including homopolymers of poly(methyl methacrylate) (PMMA), poly(tert-butyl methacrylate) (PTBMA) and poly(2-hydroxyethyl methacrylate) (PHEMA), and their random copolymers of P(MMA-TBMA) and P(MMA-HEMA) with known chemical compositions were studied. The results indicate that there is close correlations between the chemical compositions of the random copolymers and their Rt of the C8 column in the mass spectral ranges of m/z 1,800-2,000. The LC-ESI-MS analysis showed molecular weights of the copolymers distribute in the mass range of ca. 500-20,000, and the structures of polymer terminals and their monomer units can be identified.