A method of introducing a sample into an atomic spectrometer utilizes a spray head including a vibratable mesh. A liquid sample is conducted to one face of the mesh and the mesh is vibrated to expel sample droplets from the other face of the mesh into the proximal end of a flow passage axially spaced from the mesh. Also, a low pressure gas as flowed into the proximal end of the flow passage to mix with the droplets to form an aerosol in the flow passage. The vibrating of the mesh is controlled to provide in the aerosol a selected total volume of monodisperse droplets while the flow of the carrier gas is independently controlled to provide a selected rate of flow of the aerosol along the flow passage thereby to optimize consumption of the sample. Apparatus for practicing the method is also disclosed.