Sandia's hand-held MicroChemLabTM system uses a micromachined preconcentrator (PC), a gas chromatography channel (GC) and a quartz surface acoustic wave array (SAW) detector for sensitive/selective detection of gas-phase chemical analytes. Requisite system size, performance, power budget and time response mandate microfabrication of the key analytical system components. In the fielded system hybrid integration has been employed, permitting optimization of the individual components. Recent improvements in the hybrid-integrated system, using plastic, metal or silicon/glass manifolds, is described, as is system performance against semivolatile compounds and toxic industrial chemicals. The design and performance of a new three-dimensional micropreconcentrator is also introduced. To further reduce system dead volume, eliminate unheated transfer lines and simplify assembly, there is an effort to monolithically integrate the silicon PC and GC with a suitable silicon-based detector, such as a magnetically-actuated flexural plate wave sensor (magFPW) or a magnetically-actuated pivot plate resonator (PPR).