Large Volume Injection; Gas Chromatograph Requirements; Automatic Sampler Requirements - Agilent Technologies 6890 Series Operating Manual

Part 4. Using the Solvent Vent Mode

Large volume injection

Most vaporizing inlets are designed for liquid injections in the 1 to 5 µL range.
With larger injections, the vapor cloud created when the sample vaporizes may
overflow the inlet and degrade the chromatography. For the PTV, the nominal
liner liquid capacities are:
Table 18 Liner capacities
Liner
Open baffle
Glass wool packed
In the solvent vent mode, analytes are thermally trapped in the liner while the
solvent is removed. With the solvent gone, the liner volume can be used for
another injection. Injection can be repeated several times to concentrate the
analytes from a large sample volume. After injection and solvent removal, the
analytes are transferred to the column. This can replace the need for offline
concentrating and minimize loss of sample.
Multiple injections by an automatic sampler can be used with the PTV to achieve
large volume injection. A ChemStation controls the process.

Gas chromatograph requirements

• Model 6890 GC with A.2.00 or later firmware
• Agilent PTV
• Model G2613A injector (with G2612A interface card installed in the GC)

Automatic sampler requirements

• Model G1512A controller with G1512A.01.08 or later firmware.
• Model G1513A injector with G1513A.09.14 or later firmware. A second injec-
tor can be mounted for synchronous injections to the rear inlet, but only one
PTV can be mounted and it must be in the front position.
Caution
Use of the 18593A or 18593B injection tower may damage the system.
Nominal liquid capacity
µ
5 L
µ
25 L
The Programmable Temperature Vaporization Inlet
Large volume injection
Inertness
High
Lower, because of greater surface area
145