A multi-filter chemical speciation sampler and a virtual impaction particle separation inlet therefore are provided. The inlet includes a housing having a bottom, a collection tube that extends through the bottom, and collection apertures formed in the bottom, arranged around the collection tube; a first plate disposed on top of the housing, having acceleration nozzles disposed at the perimeter thereof; a second plate disposed in the housing below the first plate, having a central aperture and separation apertures disposed around the central aperture. The sampler includes: an inlet; a virtual impaction separator to further fractionate the PM into a course fraction and a fine fraction; a first separation assembly to divide the course fraction into coarse aliquots, comprising first filters to collect the coarse aliquots; a second separation assembly to divide the fine fraction into fine aliquots, comprising second filters to collect the fine aliquots.