We have applied CZE and CEC in microfluidic devices to a number of analytical problems including the analysis of chemical warfare agents, polycyclic aromatic hydrocarbons, and proteins. In addition to developments in the areas of separations, we are also heavily involved in the "front-end" of analytical systems particularly in the area of sample preconcentration. We have a particular interest in the concentration of a wide range of molecules including small molecules, biopolymers, and cells. Our current toolbox includes a microfluidic platform known as Liquid Phase μChemLab developed by a team at Sandia for protein analysis. This platform has been demonstrated with protein biotoxins, CW agent degradation products, protein preconcentration, and is suitable for other targets. Additionally, electrodeless dielectrophoresis technology developed at Sandia is an attractive alternative to filters for cell concentration.