Dionex As - Determining the Sample Loop Injection Type

3 • Operation and Maintenance
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3.6.3 Determining the Sample Loop Injection Type
When the AS is in normal or sequential mode, it can perform the
following types of sample loop injections:
• Full-loop—A full loop volume is injected.
• Large-loop—A full (large) loop volume is injected. Large loops are
200.0 to 7000.0
μL in volume.
• Partial-loop—A partial loop volume is injected.
• Partial-loop, limited-sample—A partial loop volume is injected; no
extra sample is aspirated from the vial or well.
NOTE When the AS is in simultaneous mode, it performs
only full-loop injections.
The following three parameters are used to determine the type of sample
loop injection the AS performs: cut volume, injection volume, and loop
size (see Table 3-4)
.
The cut volume, which is used only for partial-loop and partial-loop,
limited-sample injections, specifies a volume of sample to be “cut” (or
omitted) from each side of the sample during the injection process. Using
a smaller cut volume minimizes the amount of total sample aspirated from
the vial or well. However, better precision is achieved with a larger cut
volume. If you enter a cut volume of 0, the AS draws only the injection
volume from the vial or well.
Criteria for Determining the
Sample Loop Injection Type
Type of Sample Loop Injection
Performed
Injection volume ≥ loop size
(loop size = 2.5 to 199.9 μL)
Full-loop
Injection volume ≥ loop size
(loop size = 200.0 to 7000.0 μL)
Large-loop
Injection volume < loop size
(cut volume > 0)
Partial-loop
Injection volume < loop size
(cut volume = 0)
Partial-loop, limited-sample
Table 3-4. Determining the Sample Loop Injection Type