In order to develop more stable packing materials for high-temperature liquid chromatography (HTLC), a
new stationary phase, 1-naphthyl attached poly(2-hydroxyethylmethacrylate-N-methacryloyl-(L)-histi
dine-methyl-ester) (NA-PHEMAH) polymer was synthesized in this work. The NA-PHEMAH polymer
particles with 2.0–2.1 lm in diameter were then evaluated for use as a stationary phase in
high-temperature liquid chromatography. Separation of vanillin, ethyl vanillin, coumarin,
6-methylcoumarin, and 7-methylcoumarin was achieved on this NA-PHEMAH column using HTLC at
125–200 C with 2% or 5% methanol in the mobile phase. Successful separation of the test analytes
was also obtained using subcritical water chromatography (SBWC) at 200 C. Evaluation of the
long-term stability of the NA-PHEMAH stationary phase revealed that the column was stable for over
500 h at 150 C. These results demonstrate that the new NA-PHEMAH stationary phase is suitable for
high-temperature liquid chromatography separations due to its excellent stability at high temperatures.