โ Scribed by E. Klesper; W. Hartmann
No coin nor oath required. For personal study only.
An apparatus for the chromatography with supercritical dense gases (supercritical fluids) has been designed, the characteristic feature being a pressure cascade. Three decreasing pressure levels containing the supply part, the chromatographic column, and the detector, respectively are controlled by feed back loops. Independent control and programming of pressure, temperature, and feed rate thereby become possible. Separations of oligostyrenes with n-pentane/methanol as the mobile phase and porous silica as the stationary phase were carried out on analytical and preparative scales. The resolution appears to be superior to that obtainable with liquid chromatography. Mass spectra of the peaks showed that oligomeric species of 1 monomer weight are cleanly separated. The influence of the parameters, particularly pressure and temperature, on the efficiency of the separation was studied. Slow upward pressure and temperature programming were found beneficial for the separation.
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