Agilent Technologies 1200 series, Reference Manual

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218 Agilent 1200 Series Autosampler Reference Manual
7 Introduction to the Autosampler
Introduction to the Autosampler
Two models of Agilent 1200 Series autosamplers are available; within this
introduction they will be referred to as the standard and the preparative
autosamplers. Unless otherwise stated all information in this section is valid
for both models.
The Agilent 1200 Series autosamplers and Agilent 1200 Series autosamplers
are designed for use with other modules of the Agilent 1200 Series LC system,
with the HP 1050 Series, or with other LC systems if adequate remote control
inputs and outputs are available. The autosamplerss are controlled from the
Agilent 1200 Series control module or from the Agilent ChemStation for LC.
Three sample-rack sizes are available for the autosamplers. The standard
full-size rack holds 100 × 1.8 ml vials, while the two half-size racks provide
space for 40 × 1.8 ml vials and 15 × 6 ml vials respectively. Any two half-size
racks trays can be installed in the autosamplers simultaneously. A specially
designed sample-rack holding 100 × 1.8 ml vials is available for use with the
thermostatted autosamplers. The half-size racks trays are not designed for an
optimal heat transfer when they are used with a thermostatted autosampler.
The autosamplers transport mechanism uses an X-Z-Theta movement to
optimize vial pick-up and return. Vials are picked up by the gripper arm, and
positioned below the sampling unit. The gripper transport mechanism and
sampling unit are driven by motors. Movement is monitored by optical sensors
and optical encoders to ensure correct operation. The metering device is
always flushed after injection to ensure minimum carry-over.
The standard analytical head device provides injection volumes from
0.1 – 100 µl. Two preparative head devices provide injection volumes from
0.1 – 900 µl. One head is limited by a system pressure of 200 bars, the other by
a system pressure of 400 bars.
The six-port (only 5 ports are used) injection valve unit is driven by a
high-speed hybrid stepper motor. During the sampling sequence, the valve unit
bypasses the autosamplers, and connects flow from the pump to the column
directly. During injection and analysis, the valve unit directs the flow through
the autosamplers which ensures that all of the sample is injected onto the