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Graphite Furnace Procedure
for AAnalyst 800 in
Room 109
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FAST GUIDE TO OPERATING THE AA800
GRAPHITE FURNACE
BEFORE TURNING ON THE INSTRUMENT
1. Make sure the cooling system is filled to
the maximum mark.
2. Turn on the inert gas main valve (argon) and adjust the outlet
gauge pressures to the recommended value (50-58 psi). Never
exceed the maximum pressure. Replace the tank before the
main pressure gauge is shows less than 200 psi.
SETTING UP THE SYSTEM
1. Turn on the computer.
2. Install the requisite hollow cathode lamp, if it is not already
installed.
3. Turn on the spectrometer.
4. Start the software. Before doing anything WAIT until the software
detects the spectrometer and the instrument is initialized. The
screen should look like Figure1, shown below. 
Figure 1. Screen shot of WinLab software
after turning on the equipment.
5. Select the technique and perform the analysis.
Go to File > Technique. Select Furnace from the Flame
or Furnace options.
6. Select the analysis method. If the desired
method is already saved in the memory select it from the library.
Go to File > Open > Method. The Open Method dialog
window appears. Select the method and click OK. The name of the
method should be now in the toolbar giving the name and the element
to be analyzed.
7. Go through all the parameters in the method
to be sure everything is correct. To do this click on Tools
> Method Editor. The window to edit the current method
appears. For a brief introduction of methods go to the end of
this page.
8. Sample Information File (SIF). This file
stores information related to the samples. If an SIF exits, go
to File > Open > Sample Info file. To create a new
method go to File > New > Sample Info File. Fill out the
requisite information and confirm the position of all samples
in the tray.
9. Setting up the lamp. Go to Tools >
Lamp Set Up. In the column On/Off, click in the lamp to be
used. Click in the button of the column Set Up to align the lamp.
Allow lamps to warm up for 20 minutes before alignment. Be certain the mirror for the furance is in the correct position.
10. Allign the furnace. Go to Tools >
Furnace Control and click on Align Furnace. The align furnace
wizard appears. Click on automatically align furnace. Click in
adjust. Click finish.
11. Setting up the autosampler. 
In the Furnace control window click on Align
Tip, the Align Autosampler Tip wizard appears. In the task
list select Align the autosampler tip in the graphite tube. Follow
the instruction in the window. If the tip was correctly aligned
the mirror image will look like the sketch at the right.
PERFORMING THE ANALYSIS
1. First, set up the automatic analysis control.
Go to Tools > Automated Analysis Control. Methods needed
to perform the analysis are added to the table. Double click in
the table to add a method from the method list.
2. Sample information file may or may not be used. When a Sample
Information is not used enter file the location in samples in
the table.
3. When using SIF, go to the table and click in the column Sample Info File. From the drop box choose 'All' to use
all the samples defined of choose the number to be used.
4. To save the data select a Result Data Set. Choose open and
the window Select Result Data Set appears. Give a name and a description
and click OK to add a new set. NOTE: Selection of an older set
will cause prior results to be overwritten.
5. When the instrument is not being used, for a few hours, check
the box "Lamps off at the end of the analysis".
6. In the analyze tab choose the correct analysis. Run the standards
and the samples separately or in only one run. The system will
then print the information and storage the results.
Shutdown procedure
1. In the Furnace Control window, click on Flush Sampler a number
of times.
2. Empty the autosampler waste bottle. Dispose of waste solutions
correctly.
3. Remove all the samples and reagents from the sample tray. Wipe
up any spillages.
4. Switch off the spectrometer.
5. Turn off the gas supplies.
6. Exit WinLab: in the File menu, click Exit.
7. If there are no other applications for the computer for other
tasks, shut down the computer and printer.
Brief Introduction to Methods
A method is a register that the software store
in a database with all the parameters corresponding for every
analysis. Many of these parameters are optimized by the factory,
hence there is not need to change them unless the response of
the machine is not as expected.
Opening the method editor will show the window
in figure 3.
Figure 3. Main screen method editor. In
the bottom part of the screen there will be several tabs for the
different parameters of the method.
Spectrometer Tab:
When the method correctly selected, the name of the element to
be analyze should be in the frame spectrometer. Do not change
anything else in this tab. For information about a parameter press
F1.
Sampler Tab:
decide how the autosampler will handle the samples. There are
three subtabs in this window.
a. Furnace program: it is also optimized in
the factory. Unless there is a special sample, do not change these
parameters.
b. Autosampler: In the sample frame introduce the volume of sample
used for the furnace (20 µl is the standard). The diluent
volume is used only with standard addition method. When using
this calibration method tell the sampler how much to add and the
diluent location, otherwise use 0. The matrix modifiers frame
allows the introduction of a specific volume and location of two
modifiers when the instrument does the preparation. When not in
use the sample modifiers the volume should be 0 µl.
c. Sequence: in this subtab tell the instrument
how to make the injection. Pressing the button custom the
next window appears:
Figure 4. Custom sequence for injections. The only step that may require modification is the pipette step. For example, to modify the step A for injecting
only the sample go to the frame pipette and press Sample/Std.
After that click on step A and the press Enter pipette.
Calibration Tab:
There are also several subtab for this window.
a. Equation and units: Tell the instrument
which type of mathematical relationship is going to be used to
fit the data. For a large description of every equation press
F1.
b. Standard concentrations: The positions
of the standards and their concentrations have to be filled out
in this table. There are two possibilities, first to prepare standards
or let the instrument to prepare them. To prepare standards just
fill out the values and position in the table and how much of
the standard is required (use the same volume than for the samples).
Except for standard addition and then need to introduce a specific
volume of the diluent.
For the instrument to make the standards
provide a stock solution and its position. Press Calculate
Standard Volumes and in the table introduce the concentrations
of the standards required and in the frame Stocks introduce the
concentration of the stock and the location. The instrument will
calculate the appropriate volumes and will fill out the table.
In this case provide a diluent.
c. Initial calibration: nothing to do in this
window unless the previous calibration curves is being used.
d. Calibration check: this option allows the
program to stop if the correlation coefficient for the calibration
is below a given value. Or specify if the instrument should repeat
the calibration or what to do in case of a low correlation coefficient.
The basic set up of the method is complete.
Other tabs are for more advance uses. Become familiar with the
other options of the instrument press F1 in any window and information
will pop up.
