Despite the high demand for miniaturized liquid chromatographic (LC) techniques, there are only a few chip-based chromatographic systems compared to chip-based capillary electrophoretic devices [7]. First, Manz et al. [8] described an LC partially integrated onto a silicon chip in which chromatographic C8 particles were retained by frits in the column. Other devices have incorporated a physical barrier [9], tapered capillary geometries [10] or fritless bottleneck [11] and [12] to trap stationary-phase particles. Hansen et al. [13] reported microfluidic solid-phase chromatography columns formed by multilayer soft lithography. Recently, our group has demonstrated the preparation of simple and permanent multiple chromatographic columns that are suitable for parallel chromatographic separations without frits [14].