Agilent Technologies Agilent 1260 Infinity System User's Manual page 49

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Optimization of the Agilent 1260 Infinity Binary LC
How to Achieve Shorter Cycle Times
Automatic delay volume reduction (ADVR)
The Agilent 1260 Infinity High Performance Autosampler offers the
possibility of performing overlapped injections (OI) and/or automatic delay
volume reduction (ADVR). This means that the injection valve is switched
out of the flow path after the sample has reached the top of the column.
This reduces the delay volume significantly, see Figure 17 on page 49.
Figure 17 Reduction of the delay volume
The lower the flow rate, the greater the negative impact that can be
expected from delay volume. In Figure 17 on page 49, a 2.1 mm inner
diameter column was used at a flow rate of 0.6 mL/min. The delay volume
is reduced step by step from the lowest trace to the top trace. The
influence on total run time, and the impact, especially on peak width and
the heights of the first peaks, is obvious.
The drawback of overlapped injection and automatic delay volume
reduction is that the autosampler is not in the flow path for the complete
run time. For very sticky compounds this could lead to higher carry- over
and/or compound discrimination.
1260 Infinity Binary LC - System User Guide 49