PROCEDURE AND DEVICE FOR AUTOMATIC SAMPLING WITH A FLAMELESS ATOMIC ABSORPTION SPECTROMETER

摘要

1497012 Sample holders and delivery of samples BODENSEEWERK PERKIN-ELMER & CO GmbH 19 May 1976 [30 May 1975] 20685/76 Heading G2J [Also in Division F1] Samples for spectroscopic analysis are introduced successively into a graphite tube cell 12 from a series of micro-pipette tips 30 which are mounted in a holding device 18 so as to be brought sequentially in line with an aperture 36 in the cell 12 and a dispensing device 14 which first lowers each tip 30 and then discharges the sample into the cell 12, the tip 30 subsequently returning to its upper position and being replaced by the next tip 30 on rotation of the device 18. Each tip 30 is carried by a holder 22 which is urged into its upper position by a spring 24. The dispensing device comprises a cylinder 44 in which slides a piston 42 which is also urged into its upper position. Each tip 30 is forced downwards by the piston 42 on pressurizing the space in the cylinder 44 above the piston 42. When the piston 42 reaches its lower position; a duct 72 therethrough communicates with a source of inert gas at high pressure, which forces the sample from the tip 30 into the cell 12. The gas above the piston 42 is then exhausted and the piston 42 and the holder 22 move upwards under the action of springs 64, 24. In a modification the piston 42 is driven by a motor.