Sample injection arrangement for an analytical instrument

Claim 2

In an analytical instrument having an injection station, a probe-penetrable, self-sealing material forming a wall segment of said injection station for introducing a sample by a probe into an injection chamber, means for heating said injection station; said wall material exhausting volatile contaminants when said injection station is heated, a means for reducing the introduction of said contaminants from said wall material into said instrument comprising a demountable shielding body having a disc-shaped configuration disposed between an inner surface of said wall and chamber environment for shielding said inner surface from said environment, said body formed of a material which is probe penetrable and which is nonvolatile at the operating temperature.

Claim 3

In an analytical instrument having an injection station, a probe-penetrable, self-sealing material forming a wall segment of said injection station for introducing a sample by a probe into an injection chamber, means for heating said injection station, said wall material exhausting volatile contaminants when said injection station is heated, a means for reducing the introduction of said contaminants from said wall material into said instrument comprising a shielding body having an uninterrupted surface disposed adjacent an inner surface of said wall material for trapping volatile contaminants at an interface between said shielding body and said wall material, said shielding body formed of a material which is probe penetrable and which is nonvolatile at the operating temperature.

Claim 4

In an analytical instrument having an injection station, a probe-penetrable, self-sealing material forming a wall segment of said injection station for introducing a sample by a probe into an injection chamber, means for heating said injection station, said wall material exhausting volatile contaminants when said injection station is heated, a means for reducing the introduction of said contaminants from said wall material into said instrument comprising a shielding body having an uninterrupted surface disposed adjacent an inner surface of said wall material for trapping volatile contaminants at an interface between said shielding body and said wall material, said shielding body formed of a material which is probe penetrable and which is nonvolatile at the operating temperature.

Claim 5

The apparatus of claim 1 wherein said shielding body is formed of polytetrafluoroethylene.

Claim 6

The apparatus of claim 2 including a support means for simultaneously replacing said inert body and maintaining a gastight seal between said wall material and chamber.

Claim 7

In an analytical instrument having an injection block, a means for heating the block, an improved probe injection arrangement comprising: a support means coupled to said block at an injection station thereof and including a support member for supporting a first body having an inner surface thereof and formed of a probe-penetrable, self-sealing material providing a gas seal between an injection chamber environment and atmospheric environment; said body exhausting volatile contaminants when said injection station is heated; said support member having a groove formed in a cross section thereof in a direction substantially parallel to the inner surface of said body; and, a second body formed of a probe-penetrable material which is nonvolatile at the operating temperatures positioned in said groove for shielding said first body from the chamber environment, said second body comprising a segment of an elongated strip having portions thereof extending from said support member whereby said strip is adapted for manual advancement.

Claim 8

In an analytical instrument having an injection block, a means for heating the block, an improved probe injection arrangement comprising: a support means coupled to said block at an injection station thereof and including a support member for supporting a first body having an inner surface thereof and formed of a probe-penetrable, self-sealing material providing a gas seal between an injection chamber environment and atmospheric environment; said body exhausting volatile contaminants when said injection station is heated; said support member having a groove formed in a cross section thereof in a direction substantially parallel to the inner surface of said body; and, a second body formed of a probe-penetrable material which is nonvolatile at the operating temperatures positioned in said groove for shielding said first body from the chamber environment, said second body comprising a segment of an elongated strip having portions thereof extending from said support member whereby said strip is adapted for manual advancement.

Claim 9

A probe injection arrangement for a gas chromatograph comprising: an injection block having a gas flow passage formed therein; means for heating said injection block; a tubular member extending from said injection block and communicating with said passage; a cap mounted at an outer end of said tubular member, said cap including a cylindrical bore and a probe entrance aperture connected with said bOre; a first body formed of a probe-penetrable, self-sealing material positioned in said bore and forming a gas seal said aperture and said bore said body exhausting volatile contamination when heated at the operating temperature; and, a second body formed of a probe-penetrable material positioned in said bore adjacent said first body for shielding said first body from an environment of said gas passage, said second body comprising a thin disc having an uninterrupted surface and formed of a material which is probe-penetrable and nonvolatile at the operating temperature.

Claim 10

A probe injection arrangement for a gas chromatograph comprising: an injection block having a gas flow passage formed therein; means for heating said injection block; a tubular member extending from said injection block and communicating with said passage; a cap mounted at an outer end of said tubular member, said cap including a cylindrical bore and a probe entrance aperture connected with said bOre; a first body formed of a probe-penetrable, self-sealing material positioned in said bore and forming a gas seal said aperture and said bore said body exhausting volatile contamination when heated at the operating temperature; and, a second body formed of a probe-penetrable material positioned in said bore adjacent said first body for shielding said first body from an environment of said gas passage, said second body comprising a thin disc having an uninterrupted surface and formed of a material which is probe-penetrable and nonvolatile at the operating temperature.

Claim 11

The apparatus of claim 6 wherein said cap includes a groove formed in a cross section thereof and said second body is formed of an elongated strip having a portion of said length positioned in said groove.

Claim 12

The apparatus of claim 7 including means positioned between said first and second bodies for reducing sliding friction therebetween.