Varian 450-GC, User Manual

Page: 114 / 205

Injectors – 1079 PTV Injector
Page: 176 User Manual 450-GC Varian, Inc.
Features of the 1079 PTV Injector
•
The 1079 PTV can be operated isothermally or temperature programmed. The
temperature range of the Injector is from -99 to 450 °C. Sub-ambient
temperatures are achieved using cryogenic cooling.
•
Changing from one injection mode to another typically involves a change of
Injector insert and a modification to the Injector program. Glass inserts can be
easily changed from the top of the Injector.
•
Temperature programming in the splitless mode gives better recovery of labile
analytes and is useful for wide boiling point mixtures.
•
The Injector temperature profile keeps the septum cool while maintaining the
point of injection closer to the setpoint temperature.
•
The 1079 PTV Injector design facilitates large volume injection (5 - 250 µL).
•
The 1079 PTV uses positive septum purge to minimize the adsorption of
sample onto the Injector septum and to prevent contaminants from the septum
entering the column.
•
The 1079 PTV combined with the ChromatoProbe on page 198 is an effective
tool for chromatographic analysis of dirty samples (liquids, solids and slurries,
blood, urine or milk), without cleanup or extraction. The ChromatoProbe is
based on intra-Injector thermal extraction of the semi volatile compounds in a
sample microvial, while non-volatile residue is retained in the microvial, which is
disposed of after the analysis.
Automatic Start Switch
The automatic start switch is a spring loaded actuator that fits over and is
aligned with, the injection port of the 1079 PTV Injector nut. The GC run is
started when the actuator is depressed by the syringe barrel, or manually
pressed at the moment of sample injection. The GC run can also be manually
(only in local automation) started by pressing the START .
The Injector nut and automatic start swit ch assembly may
be very hot durin g inst rument operation and shou ld NOT
be touched with unprot ected hands.
1079 PTV Injector Inserts
Click here to see the 1079 PTV Injector Inserts, on page 451.
Note that all 1079 PTV Injector inserts are deactivated for maximum inertness.