A hand-held microfluidic testing device is provided that includes a housing having a cartridge receiving port, a cartridge for input to the cartridge receiving port having a sample input and a channel, where the channel includes a mixture of Raman-scattering nanoparticles and a calibration solution, where the calibration solution includes chemical compounds capable of interacting with a sample under test input to the cartridge and the Raman-scattering nanoparticles, and an optical detection system in the housing, where the optical detection system is capable of providing an illuminated electric field, where the illuminating electric field is capable of being used for Raman spectroscopy with the Raman-scattering nanoparticles and the calibration solution to analyze the sample under test input to the cartridge.

Certain configurations of a gas chromatography system comprising an internal gas generator are described. In some instances, the gas chromatography system may comprise an internal hydrogen generator to provide hydrogen gas to a chromatography column for separation of analyte species. In certain examples, the gas chromatography system can be operated without any external gas inputs.

A microscale collector and injector device comprises a microscale passive pre-concentrator (PP) and a microscale progressively-heated injector (PHI). The PP devices comprises first and second substrate portions, a first collection material, a PP heater, and an outlet. The first substrate portion defines an array of microscale diffusion channels. The first and second substrate portions cooperate to define a first compartment in fluid communication with the diffusion channels. The first collection material is disposed within the first compartment, at least partially surrounding the outlet. The PP heater is disposed in thermal communication with the second substrate portion. The PHI device comprises third and fourth substrate portions, a second collection material, and a plurality of PHI heaters. The third and fourth substrate portions cooperate to define a second compartment. The second collection material is disposed within the second compartment. The PHI heaters are disposed in thermal communication with the second compartment.