This article describes the factors that affect the selection of columns fortwo-dimensional (2D) LC×LC separations. The maximum increase in peak capacity compared with single-dimension (1D) separations is obtained by using "orthogonal" systems employing various combinations of separation mechanisms to provide as different separation selectivities as possible for the sample compounds in the first and in the second dimension systems. To obtain best results, matching the chemistry of the stationary phase,.. Dec 1, 2007 By:
Pavel Jandera
Proteins can be separated according to their isoelectric points on an ion-exchange column using pH gradients in the first dimension and according to their hydrophobicity on an RP column in the second dimension.
