Semi-automatic and automatic fluid injectors

Abstract

An apparatus for sampling and injecting measured liquid samples into the septum inlet of an analytical instrument or the like. Three sub-assemblies comprising the apparatus are (a) an injector inclusive of a barrel communicating with a hollow needle at one end for injecting fluid into through a septum and a valve communicating with the other end for interrupting flow through the barrel and needle, (b) a feed assembly inclusive of an upwardly directed probe for puncturing the septum of an inverted sample containing receptacle for supplying gas pressure to the receptacle and for transporting the sample through a conduit to the valve of the injector, (c) a magazine inclusive of a pair of concentric slidable tubes, the outer tube guiding the inner and the inner adapted to carry the inverted sample receptacle downwardly for puncturing by the probe of the feed assembly so that, the fluid contents of the vial pressurized by injection of gas into the vial via the gas inlet conduit and fluid specimen transported via the fluid specimen outlet to the barrel, whereby on the ingress of an initial portion of the fluid specimen the barrel and needle can be purged and cleaned, a measured quantity of the fluid specimen then trapped, and then injected on insertion of the dispensing end of said needle into said medium.