A package for encapsulating a functional area against an environment includes a base substrate and a cover substrate, the base substrate together with the cover substrate defining at least part of the package or defining the package, and furthermore including the at least one functional area provided in the package, and a blocking way for reducing permeation between the environment and the functional area. The package may include at least one laser bonding line, and the substrates of the package can be hermetically joined to one another by the at least one laser bonding line, and the laser bonding line has a height (HL) perpendicular to its bonding plane.

Micro gas chromatographic devices are provided having a microfluidic separation column and a plurality of capillaries where the capillaries have been independently configured in terms of the capillary length, capillary width, the packing density and packing geometry of the capillary using one or more micro pillars, the tortuosity of the capillary path, and the presence and identity of the stationary phase for use in micro gas chromatographic separation of complex mixtures of compounds. Through the plurality of capillaries, the devices are capable of discriminating between complex samples even in instances where complete separation of the components is not possible. Methods of fabrication and methods of use of the devices are also provided. The devices can be readily fabricated using known techniques. The devices can be used for the analysis of complex mixtures of compounds containing tens or hundreds of compounds in which just a few differ in presence or concentration.