Optimizing Throughput - Agilent Technologies 7697A Advanced Operation Manual

Optimizing Throughput

Advanced Operation
The 111 vial model HS automatically manages its timings to
maximize the throughput of samples submitted to it for
processing. Upon starting a sequence, it compares the
methods used for each vial, then determines how and when
to place each vial in the oven to minimize any downtime
between GC runs. Its analysis depends on:
• The HS timing parameters (wait times, equilibration times,
and so forth)
• The accuracy of the entered GC cycle time
• The number of contiguous samples in the sequence that
use the same method
• The differences in the HS parameters between each
method
• Any differences between the actual GC run time and the
entered values for HS parameters such as carrier gas flow
or pressure programs
HS throughput analysis does not consider other GC settings,
such as GC oven temperature or inlet temperature changes.
The HS cannot account for MSD solvent wait time or other
external events that occur after the GC run completes. You
must include these types of timing issues in the GC cycle time
parameter if any becomes important. For example, suppose
you temperature program the inlet. The inlet must cool down
before the next run. This will take some amount of time,
during which the GC is Not Ready and the HS may have
samples in the oven. If the cool down takes too long, the
samples would remain in the HS oven too long and trigger
the Check for ready sequence action. In this case you may need
to consider increasing the GC cycle time.
When using HS carrier gas control, any excess time left in a
HS flow or pressure ramp will be honored regardless of GC
state. If the GC oven program ends, the run ends, but the
HS would continue to execute the flow program until
finished. This case may result in reduced throughput.
Practices that may increase throughput:
• Group samples that use similar HS oven temperature and
shaking.
• Arrange samples to avoid heating, then cooling the HS
oven. Analyze samples in order of increasing HS oven
temperature.
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Method Development
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