Sample Injection Method - Hitachi ChromasterUltra Rs 6270 Instruction Manual

2.2.5 Sample Injection Method

Summary
Measurement
method
Measurement
method details
Reproducibility
Sample loss
Carry over
Injection time
The loop exchange
when the injection
volume is changed
Injection range
Commingling of
wash fluid with flow
path
AS dead volume as
system
The decline of the
sample
concentration
caused by
influences of dilution
(the diffusion).
(1) Description of each method
Select a sample injection method for the ChromasterUltra Rs
6270 Autosampler from the following three methods.
Table 2-1 Injection Methods
Cut Injection
Method
(Standard)
The amount of sample
withdrawn by the needle
is slightly larger than the
amount that will be
transferred from the
injection valve to the
column. The middle part
of the sample is
injected; the leading and
trailing ends are not
injected.
This method provides
good reproducibility,
however some of the
sample is wasted.
Syringe
Discharge rate from
Syringe
○
△ (occurrence)
◎
○
◎ (unnecessity)
◎ (broad)
◎ (nonoccurrence)
○
△ (90% to 98%)
2 - 7
All Volume
Injection Method
The entire sample
withdrawn by the needle
is transferred to into the
sample loop and into the
column.
This method is suitable
for analysis of minute
samples since no part of
the sample is wasted.
Syringe
Aspiration/Discharge
rate from syringe
△
◎ (nonoccurrence)
○
◎
◎ (unnecessity)
○ (narrow)
△ (occurrence)
○
△ (90% to 98%)
◎:Better, ○:Good, △:Acceptable
2.2.2
Full Loop
Injection Method
The sample loop is filled
with sample for
measurement.
This method provides
the best repeatability of
sample injection volume
in analysis.
Loop
The summation of the
capacity of the flow
path in the loop and
the injection valve
◎
(No influence of
syringe measurement
accuracy)
△ (occurrence)
○
◎
△ (necessity)
△ (fixity)
◎ (nonoccurrence)
◎ (loop capacity)
○ (to 99 %)