Using The Automated Needle Wash - Agilent Technologies G1329A User Manual

5
Optimizing Performance
Optimization for Lowest Carry-over

Using the Automated Needle Wash

The automated needle wash can be programmed either as "injection with
needle wash" or the needle wash can be included into the injector program.
When the automated needle wash is used, the needle is moved into a wash vial
after the sample is drawn. By washing the needle after drawing a sample, the
sample is removed from the surface of the needle immediately.
Uncapped Wash Vial
For best results, the wash vial should contain solvent in which the sample
components are soluble, and the vial should not be capped. If the wash vial is
capped, small amounts of sample remain on the surface of the septum, which
may be carried on the needle to the next sample.
Injector Program with Needle Wash
The injector program includes the command NEEDLE WASH. When this
command is included in the injector program, the needle is lowered once into
the specified wash vial before injection.
For example:
1 DRAW 5 µl
2 NEEDLE WASH vial 7
3 INJECT
Line 1 draws 5 µl from the current sample vial. Line 2 moves the needle to vial
7. Line 3 injects the sample (valve switches to main pass).
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