I
NSTRUMENT
D
ESCRIPTION
ProStar 400 AutoSampler
15
the analysis time is completed, the next injection is made starting
the sequence at step 3 with a fixed preflush of 4 µL.
Figure 4 Dispenser-controlled Injection
Pressure-controlled Injections
1. With the injection valve in load position, the coaxial needle
pair is inserted into the sample. Air pressure, applied on the
sample through the outer (air-) needle, will force the sample
via the inner (sample-) needle through the sample loop. The
duration of the headspace pressure is programmable;
appropriate duration has to be determined experimentally.
2. Injection valve switches into inject position. Sample loop is
now part of the HPLC mobile phase flow path: sample is
transported to the column. Analysis time starts.
NOTE:
A special sample drain that prevents siphoning must be connected to the
injection valve (replacing the dispenser connection). Refer to
Installation
on page 3.
Summary of Contents for ProStar 400
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