Fluid injector

In a fluid apparatus for the injection of preselected quantities of a fluid specimen into an analytical instrument wherein there is included the combination of

• (A) a syringe constituted of
• a barrel into which a fluid specimen can be loaded, and
• a plunger rod reciprocally mounted in one end of the barrel for opening the barrel for receipt of fluid specimen, and for displacement of fluid specimen from the barrel,
• (B) an injector feed assembly constituted of
• a pair of concentrically mounted needles of different diameters, each provided with an axial opening therethrough,
• an outer larger diameter needle containing a side wall opening communicating with the axial opening therethrough, and
• an inner needle of sufficiently small diameter to form an annulus between the external surface of said inner needle and the internal surface of said outer tubular needle, and
• (C) a magazine for transporting one or more fluid specimen-containing septum sealed vials, and serially positioning a vial for the pickup of a fluid specimen therefrom via projection of the dispensing end of said concentric pair of needles of said injector feed assembly (B) through the septum of a vial, gas being passed via the side wall opening of the large diameter needle through the needle annulus to pressurize the fluid contents of the vial to drive fluid specimen from the vial through the axial opening of the small diameter needle for transfer to the barrel of the syringe,
• the improvement wherein
• an end of the outer larger diameter needle of the injector feed assembly (B) containing the side wall opening is mounted directly within the end of the barrel opposite that in which the plunger is mounted, the syringe (A) and injector feed assembly (B) thus forming a unitary assembly, and
• (D) a tubular block valve through the tubular opening of which said concentric pair of needles can be projected into a vial carried by said magazine and positioned in-line therewith, said valve further including a pair of lateral channels, the first of said lateral channels fluidly communicating with a pressurized gas, the second of said lateral channels adapted to be connected to said analytical instrument, such that when the concentric pair of needles of said feed injector assembly (B) is projected through the tubular opening, through a vial septum and into a vial carried by the magazine, and an end of the smaller diameter needle immersed in a fluid specimen, gas can be passed via the first lateral channel of said block valve, the side wall opening of the large diameter needle, and via the needle annulus to pressurize the fluid contents of the vial and drive fluid specimen into the axial opening of the small diameter needle, and on retraction of the plunger rod into the syringe barrel, and on closure of said first lateral block valve channel and opening of the second lateral block channel, the fluid specimen can be displaced from the syringe barrel and expressed via said second lateral block valve channel to the analytical instrument.