Investigation of enantiomer separation by LC with a new bonded cellulose 3,5-dimethylphenylcarbamate chiral stationary phase

A chiral stationary phase has been prepared from the 3,5-dimethylphenylcarbamate of cellulose chemically bonded to 3-aminopropylsilica gel at the 6-positions of the glucose units. The phase has been used to study direct liquid chromatographic enantioselective separation of five racemates. The effects on resolution of modifiers (alcohols, THF, and chloroform), flow rate, and temperature were investigated. It was found that the concentration and structure of the alcohol modifier can affect the separation; enantiomer separations were improved to different extents by addition of THF or chloroform to the mobile phase. Flow rate and temperature can also effect the resolution of racemates. In the range 10-40 degrees C there was a linear relationship between In k (or In alpha) and I/T (r > 0.98) for four of the compounds. These results indicate retention mechanism does not change as a function of temperature.