Abstract: A concentrating vortex shaker for the simultaneous shaking and concentration of a multiplicity of liquid samples comprises a heat-conductive block having a plurality of openings for receiving laboratory vessels containing sample liquids and removably mounted on a base provided with an adjustable eccentric drive for displacing the block in a gyrating motion. An airtight cover is removably mounted on the block and forms a chamber above the samples which can be controllably evacuated. The samples can be heated or cooled by a temperature-controlled liquid which is fed through a channel formed in the block or heated by an adjustable electrical heater provided in the block mounting or cooled by a cooling plate, upon which the block mounts.

Abstract: A fraction collector or other electrically operated liquid-handling device has a tray underlying the device for collecting spilled liquid. A pitched surface in the tray gathers any spilled liquid into the vicinity of a sensor having a moisture-destructible or sensitive element which holds a switch against the force of a spring in a closed-circuit position, allowing power to be fed from a current source to the electrically operated device. Upon wetting and destruction of the element the spring is relieved to open the switch, thereby cutting off the power and stopping the operation of the liquid-handling device.