HS 55 (Batch Mode)
Installation and commissioning
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}
For AAS devices with only one sample chamber: remove the cell and also remove the
cell unit.
4.3.2
Coating the graphite tube
NOTICE
Damage to the titanium cannula
Do not coat the graphite tube using the titanium cannula of the autosampler for the
graphite tube furnace. Otherwise the cannula can no longer be used for measurements.
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Only coat the graphite tube using the standard configuration of the autosampler,
i.e., with the MFA metering hose.
Coat the graphite tube with iridium for detecting hydride-forming elements or with gold
for detecting mercury.
Recommendation
Pipette 50 µl iridium or gold master solution (1000 mg/l) into the graphite tube with
the autosampler three times in a row and allow the solution to dry on the graphite tube.
After the coating furnace program, 150 µg metallic iridium or gold remains on the tube
bottom.
Do not exceed a temperature of 2200 °C (iridium) or 1000 °C (gold) during coating and
bake-out of the graphite tube. Otherwise iridium or gold loss will occur.
}
Start the ASpect LS or ASpect CS program.
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In the Quick Start window, select the Graphite Furnace (Wall) method and initialize
the device configuration.
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Close the window with OK.
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Click the Furnace button.
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Select the Plot tab and check the box next to Graphite tube coating.
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Define the coating parameters.
– Cycles = number of pipetting cycles (recommended: 3)
– Position = position of the iridium or gold master solution on the plate of the au-
tosampler
– Vol. = sample volume to be pipetted per cycle (recommended: 50 µl)
– Element = Ir or Au
ü
The diagram on the tab shows the fixed temperature/time gradient for tube coat-
ing with iridium or gold.
}
Place the sample container with the iridium or gold master solution into the selected
position on the plate of the autosampler.
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Click Start to start the coating process.
ü
The graphite tube is coated with iridium or gold.