Bases, cyclodextrin effect columns

Today, there are a number of effective chiral stationary phases suitable for GC, some based on amino acid derivatives, some on polysiloxane polymers and some, probably the more popular, based on cyclodextrin derivatives. Very few chiral columns, if any, are packed, the vast majority being open tubular columns having various lengths and an I.D. that ranges from about 250 pm or 320 pm There has, however, been a recent trend to smaller diameter columns cf. 125 pm) to achieve higher efficiencies and even shorter analysis times. 

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