Hitachi ZA3000 Series Instruction Manual page 260

3.1 Generation of Measurement Conditions
[Addition] determines whether to add the reagent before or
after sample injection ("Pre" or "Post").
For a palladium modifier, the injection after sample may
provide a higher reproducibility because such a modifier
contains much acid and is apt to disperse in the cuvette.
"Post" is recommended to target the contents of the sample
and "Pre" to suppress the interaction between the surface
of the cuvette and the sample.
Fig. 3-26 Autosampler Window (Modifier/QC Cup No.)
NOTES: 1. Modifier is added to both unknown and standard
samples.
2. Total volume of injection into a graphite cuvette is
given by the sum of (total addition volume of
modifiers 1 to 4) + (Sample Injection Vol.).
This volume should not exceed the injection
volume allowed for the graphite cuvette.
3. In case the adding sequence (Pre or Post) is the
same in the multiple set modifiers, modifiers 1 to 4
are added in this order.
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